diff options
Diffstat (limited to 'mm')
-rw-r--r-- | mm/backing-dev.c | 448 | ||||
-rw-r--r-- | mm/filemap.c | 2 | ||||
-rw-r--r-- | mm/hugetlb.c | 110 | ||||
-rw-r--r-- | mm/hwpoison-inject.c | 15 | ||||
-rw-r--r-- | mm/init-mm.c | 6 | ||||
-rw-r--r-- | mm/kmemleak.c | 100 | ||||
-rw-r--r-- | mm/ksm.c | 71 | ||||
-rw-r--r-- | mm/memblock.c | 2 | ||||
-rw-r--r-- | mm/memcontrol.c | 462 | ||||
-rw-r--r-- | mm/memory-failure.c | 120 | ||||
-rw-r--r-- | mm/memory.c | 44 | ||||
-rw-r--r-- | mm/mempolicy.c | 82 | ||||
-rw-r--r-- | mm/migrate.c | 10 | ||||
-rw-r--r-- | mm/mmap.c | 44 | ||||
-rw-r--r-- | mm/nommu.c | 5 | ||||
-rw-r--r-- | mm/oom_kill.c | 683 | ||||
-rw-r--r-- | mm/page-writeback.c | 254 | ||||
-rw-r--r-- | mm/page_alloc.c | 33 | ||||
-rw-r--r-- | mm/page_io.c | 2 | ||||
-rw-r--r-- | mm/rmap.c | 186 | ||||
-rw-r--r-- | mm/shmem.c | 133 | ||||
-rw-r--r-- | mm/slab.c | 2 | ||||
-rw-r--r-- | mm/swapfile.c | 100 | ||||
-rw-r--r-- | mm/truncate.c | 38 | ||||
-rw-r--r-- | mm/util.c | 11 | ||||
-rw-r--r-- | mm/vmalloc.c | 11 | ||||
-rw-r--r-- | mm/vmscan.c | 548 | ||||
-rw-r--r-- | mm/vmstat.c | 8 |
28 files changed, 2128 insertions, 1402 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index f9fd3dd3916..eaa4a5bbe06 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/writeback.h> #include <linux/device.h> +#include <trace/events/writeback.h> static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0); @@ -49,8 +50,6 @@ static struct timer_list sync_supers_timer; static int bdi_sync_supers(void *); static void sync_supers_timer_fn(unsigned long); -static void bdi_add_default_flusher_task(struct backing_dev_info *bdi); - #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> #include <linux/seq_file.h> @@ -65,31 +64,25 @@ static void bdi_debug_init(void) static int bdi_debug_stats_show(struct seq_file *m, void *v) { struct backing_dev_info *bdi = m->private; - struct bdi_writeback *wb; + struct bdi_writeback *wb = &bdi->wb; unsigned long background_thresh; unsigned long dirty_thresh; unsigned long bdi_thresh; unsigned long nr_dirty, nr_io, nr_more_io, nr_wb; struct inode *inode; - /* - * inode lock is enough here, the bdi->wb_list is protected by - * RCU on the reader side - */ nr_wb = nr_dirty = nr_io = nr_more_io = 0; spin_lock(&inode_lock); - list_for_each_entry(wb, &bdi->wb_list, list) { - nr_wb++; - list_for_each_entry(inode, &wb->b_dirty, i_list) - nr_dirty++; - list_for_each_entry(inode, &wb->b_io, i_list) - nr_io++; - list_for_each_entry(inode, &wb->b_more_io, i_list) - nr_more_io++; - } + list_for_each_entry(inode, &wb->b_dirty, i_list) + nr_dirty++; + list_for_each_entry(inode, &wb->b_io, i_list) + nr_io++; + list_for_each_entry(inode, &wb->b_more_io, i_list) + nr_more_io++; spin_unlock(&inode_lock); - get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi); + global_dirty_limits(&background_thresh, &dirty_thresh); + bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh); #define K(x) ((x) << (PAGE_SHIFT - 10)) seq_printf(m, @@ -98,19 +91,16 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) "BdiDirtyThresh: %8lu kB\n" "DirtyThresh: %8lu kB\n" "BackgroundThresh: %8lu kB\n" - "WritebackThreads: %8lu\n" "b_dirty: %8lu\n" "b_io: %8lu\n" "b_more_io: %8lu\n" "bdi_list: %8u\n" - "state: %8lx\n" - "wb_list: %8u\n", + "state: %8lx\n", (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)), (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)), K(bdi_thresh), K(dirty_thresh), - K(background_thresh), nr_wb, nr_dirty, nr_io, nr_more_io, - !list_empty(&bdi->bdi_list), bdi->state, - !list_empty(&bdi->wb_list)); + K(background_thresh), nr_dirty, nr_io, nr_more_io, + !list_empty(&bdi->bdi_list), bdi->state); #undef K return 0; @@ -247,7 +237,6 @@ static int __init default_bdi_init(void) sync_supers_tsk = kthread_run(bdi_sync_supers, NULL, "sync_supers"); BUG_ON(IS_ERR(sync_supers_tsk)); - init_timer(&sync_supers_timer); setup_timer(&sync_supers_timer, sync_supers_timer_fn, 0); bdi_arm_supers_timer(); @@ -259,77 +248,6 @@ static int __init default_bdi_init(void) } subsys_initcall(default_bdi_init); -static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi) -{ - memset(wb, 0, sizeof(*wb)); - - wb->bdi = bdi; - wb->last_old_flush = jiffies; - INIT_LIST_HEAD(&wb->b_dirty); - INIT_LIST_HEAD(&wb->b_io); - INIT_LIST_HEAD(&wb->b_more_io); -} - -static void bdi_task_init(struct backing_dev_info *bdi, - struct bdi_writeback *wb) -{ - struct task_struct *tsk = current; - - spin_lock(&bdi->wb_lock); - list_add_tail_rcu(&wb->list, &bdi->wb_list); - spin_unlock(&bdi->wb_lock); - - tsk->flags |= PF_FLUSHER | PF_SWAPWRITE; - set_freezable(); - - /* - * Our parent may run at a different priority, just set us to normal - */ - set_user_nice(tsk, 0); -} - -static int bdi_start_fn(void *ptr) -{ - struct bdi_writeback *wb = ptr; - struct backing_dev_info *bdi = wb->bdi; - int ret; - - /* - * Add us to the active bdi_list - */ - spin_lock_bh(&bdi_lock); - list_add_rcu(&bdi->bdi_list, &bdi_list); - spin_unlock_bh(&bdi_lock); - - bdi_task_init(bdi, wb); - - /* - * Clear pending bit and wakeup anybody waiting to tear us down - */ - clear_bit(BDI_pending, &bdi->state); - smp_mb__after_clear_bit(); - wake_up_bit(&bdi->state, BDI_pending); - - ret = bdi_writeback_task(wb); - - /* - * Remove us from the list - */ - spin_lock(&bdi->wb_lock); - list_del_rcu(&wb->list); - spin_unlock(&bdi->wb_lock); - - /* - * Flush any work that raced with us exiting. No new work - * will be added, since this bdi isn't discoverable anymore. - */ - if (!list_empty(&bdi->work_list)) - wb_do_writeback(wb, 1); - - wb->task = NULL; - return ret; -} - int bdi_has_dirty_io(struct backing_dev_info *bdi) { return wb_has_dirty_io(&bdi->wb); @@ -348,10 +266,10 @@ static void bdi_flush_io(struct backing_dev_info *bdi) } /* - * kupdated() used to do this. We cannot do it from the bdi_forker_task() + * kupdated() used to do this. We cannot do it from the bdi_forker_thread() * or we risk deadlocking on ->s_umount. The longer term solution would be * to implement sync_supers_bdi() or similar and simply do it from the - * bdi writeback tasks individually. + * bdi writeback thread individually. */ static int bdi_sync_supers(void *unused) { @@ -387,144 +305,198 @@ static void sync_supers_timer_fn(unsigned long unused) bdi_arm_supers_timer(); } -static int bdi_forker_task(void *ptr) +static void wakeup_timer_fn(unsigned long data) +{ + struct backing_dev_info *bdi = (struct backing_dev_info *)data; + + spin_lock_bh(&bdi->wb_lock); + if (bdi->wb.task) { + trace_writeback_wake_thread(bdi); + wake_up_process(bdi->wb.task); + } else { + /* + * When bdi tasks are inactive for long time, they are killed. + * In this case we have to wake-up the forker thread which + * should create and run the bdi thread. + */ + trace_writeback_wake_forker_thread(bdi); + wake_up_process(default_backing_dev_info.wb.task); + } + spin_unlock_bh(&bdi->wb_lock); +} + +/* + * This function is used when the first inode for this bdi is marked dirty. It + * wakes-up the corresponding bdi thread which should then take care of the + * periodic background write-out of dirty inodes. Since the write-out would + * starts only 'dirty_writeback_interval' centisecs from now anyway, we just + * set up a timer which wakes the bdi thread up later. + * + * Note, we wouldn't bother setting up the timer, but this function is on the + * fast-path (used by '__mark_inode_dirty()'), so we save few context switches + * by delaying the wake-up. + */ +void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi) +{ + unsigned long timeout; + + timeout = msecs_to_jiffies(dirty_writeback_interval * 10); + mod_timer(&bdi->wb.wakeup_timer, jiffies + timeout); +} + +/* + * Calculate the longest interval (jiffies) bdi threads are allowed to be + * inactive. + */ +static unsigned long bdi_longest_inactive(void) +{ + unsigned long interval; + + interval = msecs_to_jiffies(dirty_writeback_interval * 10); + return max(5UL * 60 * HZ, interval); +} + +static int bdi_forker_thread(void *ptr) { struct bdi_writeback *me = ptr; - bdi_task_init(me->bdi, me); + current->flags |= PF_FLUSHER | PF_SWAPWRITE; + set_freezable(); + + /* + * Our parent may run at a different priority, just set us to normal + */ + set_user_nice(current, 0); for (;;) { - struct backing_dev_info *bdi, *tmp; - struct bdi_writeback *wb; + struct task_struct *task = NULL; + struct backing_dev_info *bdi; + enum { + NO_ACTION, /* Nothing to do */ + FORK_THREAD, /* Fork bdi thread */ + KILL_THREAD, /* Kill inactive bdi thread */ + } action = NO_ACTION; /* * Temporary measure, we want to make sure we don't see * dirty data on the default backing_dev_info */ - if (wb_has_dirty_io(me) || !list_empty(&me->bdi->work_list)) + if (wb_has_dirty_io(me) || !list_empty(&me->bdi->work_list)) { + del_timer(&me->wakeup_timer); wb_do_writeback(me, 0); + } spin_lock_bh(&bdi_lock); + set_current_state(TASK_INTERRUPTIBLE); - /* - * Check if any existing bdi's have dirty data without - * a thread registered. If so, set that up. - */ - list_for_each_entry_safe(bdi, tmp, &bdi_list, bdi_list) { - if (bdi->wb.task) - continue; - if (list_empty(&bdi->work_list) && - !bdi_has_dirty_io(bdi)) + list_for_each_entry(bdi, &bdi_list, bdi_list) { + bool have_dirty_io; + + if (!bdi_cap_writeback_dirty(bdi) || + bdi_cap_flush_forker(bdi)) continue; - bdi_add_default_flusher_task(bdi); - } + WARN(!test_bit(BDI_registered, &bdi->state), + "bdi %p/%s is not registered!\n", bdi, bdi->name); - set_current_state(TASK_INTERRUPTIBLE); + have_dirty_io = !list_empty(&bdi->work_list) || + wb_has_dirty_io(&bdi->wb); - if (list_empty(&bdi_pending_list)) { - unsigned long wait; + /* + * If the bdi has work to do, but the thread does not + * exist - create it. + */ + if (!bdi->wb.task && have_dirty_io) { + /* + * Set the pending bit - if someone will try to + * unregister this bdi - it'll wait on this bit. + */ + set_bit(BDI_pending, &bdi->state); + action = FORK_THREAD; + break; + } + + spin_lock(&bdi->wb_lock); + + /* + * If there is no work to do and the bdi thread was + * inactive long enough - kill it. The wb_lock is taken + * to make sure no-one adds more work to this bdi and + * wakes the bdi thread up. + */ + if (bdi->wb.task && !have_dirty_io && + time_after(jiffies, bdi->wb.last_active + + bdi_longest_inactive())) { + task = bdi->wb.task; + bdi->wb.task = NULL; + spin_unlock(&bdi->wb_lock); + set_bit(BDI_pending, &bdi->state); + action = KILL_THREAD; + break; + } + spin_unlock(&bdi->wb_lock); + } + spin_unlock_bh(&bdi_lock); - spin_unlock_bh(&bdi_lock); - wait = msecs_to_jiffies(dirty_writeback_interval * 10); - if (wait) - schedule_timeout(wait); + /* Keep working if default bdi still has things to do */ + if (!list_empty(&me->bdi->work_list)) + __set_current_state(TASK_RUNNING); + + switch (action) { + case FORK_THREAD: + __set_current_state(TASK_RUNNING); + task = kthread_run(bdi_writeback_thread, &bdi->wb, "flush-%s", + dev_name(bdi->dev)); + if (IS_ERR(task)) { + /* + * If thread creation fails, force writeout of + * the bdi from the thread. + */ + bdi_flush_io(bdi); + } else { + /* + * The spinlock makes sure we do not lose + * wake-ups when racing with 'bdi_queue_work()'. + */ + spin_lock_bh(&bdi->wb_lock); + bdi->wb.task = task; + spin_unlock_bh(&bdi->wb_lock); + } + break; + + case KILL_THREAD: + __set_current_state(TASK_RUNNING); + kthread_stop(task); + break; + + case NO_ACTION: + if (!wb_has_dirty_io(me) || !dirty_writeback_interval) + /* + * There are no dirty data. The only thing we + * should now care about is checking for + * inactive bdi threads and killing them. Thus, + * let's sleep for longer time, save energy and + * be friendly for battery-driven devices. + */ + schedule_timeout(bdi_longest_inactive()); else - schedule(); + schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10)); try_to_freeze(); + /* Back to the main loop */ continue; } - __set_current_state(TASK_RUNNING); - - /* - * This is our real job - check for pending entries in - * bdi_pending_list, and create the tasks that got added - */ - bdi = list_entry(bdi_pending_list.next, struct backing_dev_info, - bdi_list); - list_del_init(&bdi->bdi_list); - spin_unlock_bh(&bdi_lock); - - wb = &bdi->wb; - wb->task = kthread_run(bdi_start_fn, wb, "flush-%s", - dev_name(bdi->dev)); /* - * If task creation fails, then readd the bdi to - * the pending list and force writeout of the bdi - * from this forker thread. That will free some memory - * and we can try again. + * Clear pending bit and wakeup anybody waiting to tear us down. */ - if (IS_ERR(wb->task)) { - wb->task = NULL; - - /* - * Add this 'bdi' to the back, so we get - * a chance to flush other bdi's to free - * memory. - */ - spin_lock_bh(&bdi_lock); - list_add_tail(&bdi->bdi_list, &bdi_pending_list); - spin_unlock_bh(&bdi_lock); - - bdi_flush_io(bdi); - } + clear_bit(BDI_pending, &bdi->state); + smp_mb__after_clear_bit(); + wake_up_bit(&bdi->state, BDI_pending); } return 0; } -static void bdi_add_to_pending(struct rcu_head *head) -{ - struct backing_dev_info *bdi; - - bdi = container_of(head, struct backing_dev_info, rcu_head); - INIT_LIST_HEAD(&bdi->bdi_list); - - spin_lock(&bdi_lock); - list_add_tail(&bdi->bdi_list, &bdi_pending_list); - spin_unlock(&bdi_lock); - - /* - * We are now on the pending list, wake up bdi_forker_task() - * to finish the job and add us back to the active bdi_list - */ - wake_up_process(default_backing_dev_info.wb.task); -} - -/* - * Add the default flusher task that gets created for any bdi - * that has dirty data pending writeout - */ -void static bdi_add_default_flusher_task(struct backing_dev_info *bdi) -{ - if (!bdi_cap_writeback_dirty(bdi)) - return; - - if (WARN_ON(!test_bit(BDI_registered, &bdi->state))) { - printk(KERN_ERR "bdi %p/%s is not registered!\n", - bdi, bdi->name); - return; - } - - /* - * Check with the helper whether to proceed adding a task. Will only - * abort if we two or more simultanous calls to - * bdi_add_default_flusher_task() occured, further additions will block - * waiting for previous additions to finish. - */ - if (!test_and_set_bit(BDI_pending, &bdi->state)) { - list_del_rcu(&bdi->bdi_list); - - /* - * We must wait for the current RCU period to end before - * moving to the pending list. So schedule that operation - * from an RCU callback. - */ - call_rcu(&bdi->rcu_head, bdi_add_to_pending); - } -} - /* * Remove bdi from bdi_list, and ensure that it is no longer visible */ @@ -541,23 +513,16 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, const char *fmt, ...) { va_list args; - int ret = 0; struct device *dev; if (bdi->dev) /* The driver needs to use separate queues per device */ - goto exit; + return 0; va_start(args, fmt); dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args); va_end(args); - if (IS_ERR(dev)) { - ret = PTR_ERR(dev); - goto exit; - } - - spin_lock_bh(&bdi_lock); - list_add_tail_rcu(&bdi->bdi_list, &bdi_list); - spin_unlock_bh(&bdi_lock); + if (IS_ERR(dev)) + return PTR_ERR(dev); bdi->dev = dev; @@ -569,21 +534,21 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, if (bdi_cap_flush_forker(bdi)) { struct bdi_writeback *wb = &bdi->wb; - wb->task = kthread_run(bdi_forker_task, wb, "bdi-%s", + wb->task = kthread_run(bdi_forker_thread, wb, "bdi-%s", dev_name(dev)); - if (IS_ERR(wb->task)) { - wb->task = NULL; - ret = -ENOMEM; - - bdi_remove_from_list(bdi); - goto exit; - } + if (IS_ERR(wb->task)) + return PTR_ERR(wb->task); } bdi_debug_register(bdi, dev_name(dev)); set_bit(BDI_registered, &bdi->state); -exit: - return ret; + + spin_lock_bh(&bdi_lock); + list_add_tail_rcu(&bdi->bdi_list, &bdi_list); + spin_unlock_bh(&bdi_lock); + + trace_writeback_bdi_register(bdi); + return 0; } EXPORT_SYMBOL(bdi_register); @@ -598,31 +563,29 @@ EXPORT_SYMBOL(bdi_register_dev); */ static void bdi_wb_shutdown(struct backing_dev_info *bdi) { - struct bdi_writeback *wb; - if (!bdi_cap_writeback_dirty(bdi)) return; /* - * If setup is pending, wait for that to complete first + * Make sure nobody finds us on the bdi_list anymore */ - wait_on_bit(&bdi->state, BDI_pending, bdi_sched_wait, - TASK_UNINTERRUPTIBLE); + bdi_remove_from_list(bdi); /* - * Make sure nobody finds us on the bdi_list anymore + * If setup is pending, wait for that to complete first */ - bdi_remove_from_list(bdi); + wait_on_bit(&bdi->state, BDI_pending, bdi_sched_wait, + TASK_UNINTERRUPTIBLE); /* - * Finally, kill the kernel threads. We don't need to be RCU + * Finally, kill the kernel thread. We don't need to be RCU * safe anymore, since the bdi is gone from visibility. Force * unfreeze of the thread before calling kthread_stop(), otherwise * it would never exet if it is currently stuck in the refrigerator. */ - list_for_each_entry(wb, &bdi->wb_list, list) { - thaw_process(wb->task); - kthread_stop(wb->task); + if (bdi->wb.task) { + thaw_process(bdi->wb.task); + kthread_stop(bdi->wb.task); } } @@ -644,7 +607,9 @@ static void bdi_prune_sb(struct backing_dev_info *bdi) void bdi_unregister(struct backing_dev_info *bdi) { if (bdi->dev) { + trace_writeback_bdi_unregister(bdi); bdi_prune_sb(bdi); + del_timer_sync(&bdi->wb.wakeup_timer); if (!bdi_cap_flush_forker(bdi)) bdi_wb_shutdown(bdi); @@ -655,6 +620,18 @@ void bdi_unregister(struct backing_dev_info *bdi) } EXPORT_SYMBOL(bdi_unregister); +static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi) +{ + memset(wb, 0, sizeof(*wb)); + + wb->bdi = bdi; + wb->last_old_flush = jiffies; + INIT_LIST_HEAD(&wb->b_dirty); + INIT_LIST_HEAD(&wb->b_io); + INIT_LIST_HEAD(&wb->b_more_io); + setup_timer(&wb->wakeup_timer, wakeup_timer_fn, (unsigned long)bdi); +} + int bdi_init(struct backing_dev_info *bdi) { int i, err; @@ -666,7 +643,6 @@ int bdi_init(struct backing_dev_info *bdi) bdi->max_prop_frac = PROP_FRAC_BASE; spin_lock_init(&bdi->wb_lock); INIT_LIST_HEAD(&bdi->bdi_list); - INIT_LIST_HEAD(&bdi->wb_list); INIT_LIST_HEAD(&bdi->work_list); bdi_wb_init(&bdi->wb, bdi); diff --git a/mm/filemap.c b/mm/filemap.c index 20e5642e9f9..3d4df44e422 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2238,14 +2238,12 @@ static ssize_t generic_perform_write(struct file *file, do { struct page *page; - pgoff_t index; /* Pagecache index for current page */ unsigned long offset; /* Offset into pagecache page */ unsigned long bytes; /* Bytes to write to page */ size_t copied; /* Bytes copied from user */ void *fsdata; offset = (pos & (PAGE_CACHE_SIZE - 1)); - index = pos >> PAGE_CACHE_SHIFT; bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset, iov_iter_count(i)); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 54d42b009db..cc5be788a39 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -18,6 +18,9 @@ #include <linux/bootmem.h> #include <linux/sysfs.h> #include <linux/slab.h> +#include <linux/rmap.h> +#include <linux/swap.h> +#include <linux/swapops.h> #include <asm/page.h> #include <asm/pgtable.h> @@ -220,6 +223,12 @@ static pgoff_t vma_hugecache_offset(struct hstate *h, (vma->vm_pgoff >> huge_page_order(h)); } +pgoff_t linear_hugepage_index(struct vm_area_struct *vma, + unsigned long address) +{ + return vma_hugecache_offset(hstate_vma(vma), vma, address); +} + /* * Return the size of the pages allocated when backing a VMA. In the majority * cases this will be same size as used by the page table entries. @@ -552,6 +561,7 @@ static void free_huge_page(struct page *page) set_page_private(page, 0); page->mapping = NULL; BUG_ON(page_count(page)); + BUG_ON(page_mapcount(page)); INIT_LIST_HEAD(&page->lru); spin_lock(&hugetlb_lock); @@ -605,6 +615,8 @@ int PageHuge(struct page *page) return dtor == free_huge_page; } +EXPORT_SYMBOL_GPL(PageHuge); + static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) { struct page *page; @@ -2129,6 +2141,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, entry = huge_ptep_get(src_pte); ptepage = pte_page(entry); get_page(ptepage); + page_dup_rmap(ptepage); set_huge_pte_at(dst, addr, dst_pte, entry); } spin_unlock(&src->page_table_lock); @@ -2140,6 +2153,19 @@ nomem: return -ENOMEM; } +static int is_hugetlb_entry_hwpoisoned(pte_t pte) +{ + swp_entry_t swp; + + if (huge_pte_none(pte) || pte_present(pte)) + return 0; + swp = pte_to_swp_entry(pte); + if (non_swap_entry(swp) && is_hwpoison_entry(swp)) { + return 1; + } else + return 0; +} + void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long end, struct page *ref_page) { @@ -2198,6 +2224,12 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, if (huge_pte_none(pte)) continue; + /* + * HWPoisoned hugepage is already unmapped and dropped reference + */ + if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) + continue; + page = pte_page(pte); if (pte_dirty(pte)) set_page_dirty(page); @@ -2207,6 +2239,7 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, flush_tlb_range(vma, start, end); mmu_notifier_invalidate_range_end(mm, start, end); list_for_each_entry_safe(page, tmp, &page_list, lru) { + page_remove_rmap(page); list_del(&page->lru); put_page(page); } @@ -2272,6 +2305,9 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, return 1; } +/* + * Hugetlb_cow() should be called with page lock of the original hugepage held. + */ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *ptep, pte_t pte, struct page *pagecache_page) @@ -2286,8 +2322,13 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, retry_avoidcopy: /* If no-one else is actually using this page, avoid the copy * and just make the page writable */ - avoidcopy = (page_count(old_page) == 1); + avoidcopy = (page_mapcount(old_page) == 1); if (avoidcopy) { + if (!trylock_page(old_page)) { + if (PageAnon(old_page)) + page_move_anon_rmap(old_page, vma, address); + } else + unlock_page(old_page); set_huge_ptep_writable(vma, address, ptep); return 0; } @@ -2338,6 +2379,13 @@ retry_avoidcopy: return -PTR_ERR(new_page); } + /* + * When the original hugepage is shared one, it does not have + * anon_vma prepared. + */ + if (unlikely(anon_vma_prepare(vma))) + return VM_FAULT_OOM; + copy_huge_page(new_page, old_page, address, vma); __SetPageUptodate(new_page); @@ -2349,11 +2397,19 @@ retry_avoidcopy: ptep = huge_pte_offset(mm, address & huge_page_mask(h)); if (likely(pte_same(huge_ptep_get(ptep), pte))) { /* Break COW */ + mmu_notifier_invalidate_range_start(mm, + address & huge_page_mask(h), + (address & huge_page_mask(h)) + huge_page_size(h)); huge_ptep_clear_flush(vma, address, ptep); set_huge_pte_at(mm, address, ptep, make_huge_pte(vma, new_page, 1)); + page_remove_rmap(old_page); + hugepage_add_anon_rmap(new_page, vma, address); /* Make the old page be freed below */ new_page = old_page; + mmu_notifier_invalidate_range_end(mm, + address & huge_page_mask(h), + (address & huge_page_mask(h)) + huge_page_size(h)); } page_cache_release(new_page); page_cache_release(old_page); @@ -2452,10 +2508,29 @@ retry: spin_lock(&inode->i_lock); inode->i_blocks += blocks_per_huge_page(h); spin_unlock(&inode->i_lock); + page_dup_rmap(page); } else { lock_page(page); - page->mapping = HUGETLB_POISON; + if (unlikely(anon_vma_prepare(vma))) { + ret = VM_FAULT_OOM; + goto backout_unlocked; + } + hugepage_add_new_anon_rmap(page, vma, address); } + } else { + page_dup_rmap(page); + } + + /* + * Since memory error handler replaces pte into hwpoison swap entry + * at the time of error handling, a process which reserved but not have + * the mapping to the error hugepage does not have hwpoison swap entry. + * So we need to block accesses from such a process by checking + * PG_hwpoison bit here. + */ + if (unlikely(PageHWPoison(page))) { + ret = VM_FAULT_HWPOISON; + goto backout_unlocked; } /* @@ -2507,10 +2582,18 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, pte_t *ptep; pte_t entry; int ret; + struct page *page = NULL; struct page *pagecache_page = NULL; static DEFINE_MUTEX(hugetlb_instantiation_mutex); struct hstate *h = hstate_vma(vma); + ptep = huge_pte_offset(mm, address); + if (ptep) { + entry = huge_ptep_get(ptep); + if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) + return VM_FAULT_HWPOISON; + } + ptep = huge_pte_alloc(mm, address, huge_page_size(h)); if (!ptep) return VM_FAULT_OOM; @@ -2548,6 +2631,11 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, vma, address); } + if (!pagecache_page) { + page = pte_page(entry); + lock_page(page); + } + spin_lock(&mm->page_table_lock); /* Check for a racing update before calling hugetlb_cow */ if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) @@ -2573,6 +2661,8 @@ out_page_table_lock: if (pagecache_page) { unlock_page(pagecache_page); put_page(pagecache_page); + } else { + unlock_page(page); } out_mutex: @@ -2785,3 +2875,19 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) hugetlb_put_quota(inode->i_mapping, (chg - freed)); hugetlb_acct_memory(h, -(chg - freed)); } + +/* + * This function is called from memory failure code. + * Assume the caller holds page lock of the head page. + */ +void __isolate_hwpoisoned_huge_page(struct page *hpage) +{ + struct hstate *h = page_hstate(hpage); + int nid = page_to_nid(hpage); + + spin_lock(&hugetlb_lock); + list_del(&hpage->lru); + h->free_huge_pages--; + h->free_huge_pages_node[nid]--; + spin_unlock(&hugetlb_lock); +} diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c index 10ea71905c1..0948f1072d6 100644 --- a/mm/hwpoison-inject.c +++ b/mm/hwpoison-inject.c @@ -5,6 +5,7 @@ #include <linux/mm.h> #include <linux/swap.h> #include <linux/pagemap.h> +#include <linux/hugetlb.h> #include "internal.h" static struct dentry *hwpoison_dir; @@ -13,6 +14,7 @@ static int hwpoison_inject(void *data, u64 val) { unsigned long pfn = val; struct page *p; + struct page *hpage; int err; if (!capable(CAP_SYS_ADMIN)) @@ -24,18 +26,19 @@ static int hwpoison_inject(void *data, u64 val) return -ENXIO; p = pfn_to_page(pfn); + hpage = compound_head(p); /* * This implies unable to support free buddy pages. */ - if (!get_page_unless_zero(p)) + if (!get_page_unless_zero(hpage)) return 0; - if (!PageLRU(p)) + if (!PageLRU(p) && !PageHuge(p)) shake_page(p, 0); /* * This implies unable to support non-LRU pages. */ - if (!PageLRU(p)) + if (!PageLRU(p) && !PageHuge(p)) return 0; /* @@ -44,9 +47,9 @@ static int hwpoison_inject(void *data, u64 val) * We temporarily take page lock for try_get_mem_cgroup_from_page(). * __memory_failure() will redo the check reliably inside page lock. */ - lock_page(p); - err = hwpoison_filter(p); - unlock_page(p); + lock_page(hpage); + err = hwpoison_filter(hpage); + unlock_page(hpage); if (err) return 0; diff --git a/mm/init-mm.c b/mm/init-mm.c index 57aba0da966..1d29cdfe8eb 100644 --- a/mm/init-mm.c +++ b/mm/init-mm.c @@ -7,6 +7,11 @@ #include <asm/atomic.h> #include <asm/pgtable.h> +#include <asm/mmu.h> + +#ifndef INIT_MM_CONTEXT +#define INIT_MM_CONTEXT(name) +#endif struct mm_struct init_mm = { .mm_rb = RB_ROOT, @@ -17,4 +22,5 @@ struct mm_struct init_mm = { .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), .mmlist = LIST_HEAD_INIT(init_mm.mmlist), .cpu_vm_mask = CPU_MASK_ALL, + INIT_MM_CONTEXT(init_mm) }; diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 2c0d032ac89..bd9bc214091 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -211,6 +211,9 @@ static signed long jiffies_scan_wait; static int kmemleak_stack_scan = 1; /* protects the memory scanning, parameters and debug/kmemleak file access */ static DEFINE_MUTEX(scan_mutex); +/* setting kmemleak=on, will set this var, skipping the disable */ +static int kmemleak_skip_disable; + /* * Early object allocation/freeing logging. Kmemleak is initialized after the @@ -398,7 +401,9 @@ static struct kmemleak_object *lookup_object(unsigned long ptr, int alias) object = prio_tree_entry(node, struct kmemleak_object, tree_node); if (!alias && object->pointer != ptr) { - kmemleak_warn("Found object by alias"); + pr_warning("Found object by alias at 0x%08lx\n", ptr); + dump_stack(); + dump_object_info(object); object = NULL; } } else @@ -695,7 +700,7 @@ static void paint_ptr(unsigned long ptr, int color) } /* - * Make a object permanently as gray-colored so that it can no longer be + * Mark an object permanently as gray-colored so that it can no longer be * reported as a leak. This is used in general to mark a false positive. */ static void make_gray_object(unsigned long ptr) @@ -838,10 +843,19 @@ out: rcu_read_unlock(); } -/* - * Memory allocation function callback. This function is called from the - * kernel allocators when a new block is allocated (kmem_cache_alloc, kmalloc, - * vmalloc etc.). +/** + * kmemleak_alloc - register a newly allocated object + * @ptr: pointer to beginning of the object + * @size: size of the object + * @min_count: minimum number of references to this object. If during memory + * scanning a number of references less than @min_count is found, + * the object is reported as a memory leak. If @min_count is 0, + * the object is never reported as a leak. If @min_count is -1, + * the object is ignored (not scanned and not reported as a leak) + * @gfp: kmalloc() flags used for kmemleak internal memory allocations + * + * This function is called from the kernel allocators when a new object + * (memory block) is allocated (kmem_cache_alloc, kmalloc, vmalloc etc.). */ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count, gfp_t gfp) @@ -855,9 +869,12 @@ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count, } EXPORT_SYMBOL_GPL(kmemleak_alloc); -/* - * Memory freeing function callback. This function is called from the kernel - * allocators when a block is freed (kmem_cache_free, kfree, vfree etc.). +/** + * kmemleak_free - unregister a previously registered object + * @ptr: pointer to beginning of the object + * + * This function is called from the kernel allocators when an object (memory + * block) is freed (kmem_cache_free, kfree, vfree etc.). */ void __ref kmemleak_free(const void *ptr) { @@ -870,9 +887,14 @@ void __ref kmemleak_free(const void *ptr) } EXPORT_SYMBOL_GPL(kmemleak_free); -/* - * Partial memory freeing function callback. This function is usually called - * from bootmem allocator when (part of) a memory block is freed. +/** + * kmemleak_free_part - partially unregister a previously registered object + * @ptr: pointer to the beginning or inside the object. This also + * represents the start of the range to be freed + * @size: size to be unregistered + * + * This function is called when only a part of a memory block is freed + * (usually from the bootmem allocator). */ void __ref kmemleak_free_part(const void *ptr, size_t size) { @@ -885,9 +907,12 @@ void __ref kmemleak_free_part(const void *ptr, size_t size) } EXPORT_SYMBOL_GPL(kmemleak_free_part); -/* - * Mark an already allocated memory block as a false positive. This will cause - * the block to no longer be reported as leak and always be scanned. +/** + * kmemleak_not_leak - mark an allocated object as false positive + * @ptr: pointer to beginning of the object + * + * Calling this function on an object will cause the memory block to no longer + * be reported as leak and always be scanned. */ void __ref kmemleak_not_leak(const void *ptr) { @@ -900,10 +925,14 @@ void __ref kmemleak_not_leak(const void *ptr) } EXPORT_SYMBOL(kmemleak_not_leak); -/* - * Ignore a memory block. This is usually done when it is known that the - * corresponding block is not a leak and does not contain any references to - * other allocated memory blocks. +/** + * kmemleak_ignore - ignore an allocated object + * @ptr: pointer to beginning of the object + * + * Calling this function on an object will cause the memory block to be + * ignored (not scanned and not reported as a leak). This is usually done when + * it is known that the corresponding block is not a leak and does not contain + * any references to other allocated memory blocks. */ void __ref kmemleak_ignore(const void *ptr) { @@ -916,8 +945,16 @@ void __ref kmemleak_ignore(const void *ptr) } EXPORT_SYMBOL(kmemleak_ignore); -/* - * Limit the range to be scanned in an allocated memory block. +/** + * kmemleak_scan_area - limit the range to be scanned in an allocated object + * @ptr: pointer to beginning or inside the object. This also + * represents the start of the scan area + * @size: size of the scan area + * @gfp: kmalloc() flags used for kmemleak internal memory allocations + * + * This function is used when it is known that only certain parts of an object + * contain references to other objects. Kmemleak will only scan these areas + * reducing the number false negatives. */ void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) { @@ -930,8 +967,14 @@ void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) } EXPORT_SYMBOL(kmemleak_scan_area); -/* - * Inform kmemleak not to scan the given memory block. +/** + * kmemleak_no_scan - do not scan an allocated object + * @ptr: pointer to beginning of the object + * + * This function notifies kmemleak not to scan the given memory block. Useful + * in situations where it is known that the given object does not contain any + * references to other objects. Kmemleak will not scan such objects reducing + * the number of false negatives. */ void __ref kmemleak_no_scan(const void *ptr) { @@ -1602,7 +1645,9 @@ static int kmemleak_boot_config(char *str) return -EINVAL; if (strcmp(str, "off") == 0) kmemleak_disable(); - else if (strcmp(str, "on") != 0) + else if (strcmp(str, "on") == 0) + kmemleak_skip_disable = 1; + else return -EINVAL; return 0; } @@ -1616,6 +1661,13 @@ void __init kmemleak_init(void) int i; unsigned long flags; +#ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF + if (!kmemleak_skip_disable) { + kmemleak_disable(); + return; + } +#endif + jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE); jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000); @@ -33,6 +33,7 @@ #include <linux/mmu_notifier.h> #include <linux/swap.h> #include <linux/ksm.h> +#include <linux/hash.h> #include <asm/tlbflush.h> #include "internal.h" @@ -153,8 +154,9 @@ struct rmap_item { static struct rb_root root_stable_tree = RB_ROOT; static struct rb_root root_unstable_tree = RB_ROOT; -#define MM_SLOTS_HASH_HEADS 1024 -static struct hlist_head *mm_slots_hash; +#define MM_SLOTS_HASH_SHIFT 10 +#define MM_SLOTS_HASH_HEADS (1 << MM_SLOTS_HASH_SHIFT) +static struct hlist_head mm_slots_hash[MM_SLOTS_HASH_HEADS]; static struct mm_slot ksm_mm_head = { .mm_list = LIST_HEAD_INIT(ksm_mm_head.mm_list), @@ -269,28 +271,13 @@ static inline void free_mm_slot(struct mm_slot *mm_slot) kmem_cache_free(mm_slot_cache, mm_slot); } -static int __init mm_slots_hash_init(void) -{ - mm_slots_hash = kzalloc(MM_SLOTS_HASH_HEADS * sizeof(struct hlist_head), - GFP_KERNEL); - if (!mm_slots_hash) - return -ENOMEM; - return 0; -} - -static void __init mm_slots_hash_free(void) -{ - kfree(mm_slots_hash); -} - static struct mm_slot *get_mm_slot(struct mm_struct *mm) { struct mm_slot *mm_slot; struct hlist_head *bucket; struct hlist_node *node; - bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct)) - % MM_SLOTS_HASH_HEADS]; + bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)]; hlist_for_each_entry(mm_slot, node, bucket, link) { if (mm == mm_slot->mm) return mm_slot; @@ -303,8 +290,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm, { struct hlist_head *bucket; - bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct)) - % MM_SLOTS_HASH_HEADS]; + bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)]; mm_slot->mm = mm; hlist_add_head(&mm_slot->link, bucket); } @@ -318,19 +304,14 @@ static void hold_anon_vma(struct rmap_item *rmap_item, struct anon_vma *anon_vma) { rmap_item->anon_vma = anon_vma; - atomic_inc(&anon_vma->external_refcount); + get_anon_vma(anon_vma); } -static void drop_anon_vma(struct rmap_item *rmap_item) +static void ksm_drop_anon_vma(struct rmap_item *rmap_item) { struct anon_vma *anon_vma = rmap_item->anon_vma; - if (atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->lock)) { - int empty = list_empty(&anon_vma->head); - spin_unlock(&anon_vma->lock); - if (empty) - anon_vma_free(anon_vma); - } + drop_anon_vma(anon_vma); } /* @@ -415,7 +396,7 @@ static void break_cow(struct rmap_item *rmap_item) * It is not an accident that whenever we want to break COW * to undo, we also need to drop a reference to the anon_vma. */ - drop_anon_vma(rmap_item); + ksm_drop_anon_vma(rmap_item); down_read(&mm->mmap_sem); if (ksm_test_exit(mm)) @@ -470,7 +451,7 @@ static void remove_node_from_stable_tree(struct stable_node *stable_node) ksm_pages_sharing--; else ksm_pages_shared--; - drop_anon_vma(rmap_item); + ksm_drop_anon_vma(rmap_item); rmap_item->address &= PAGE_MASK; cond_resched(); } @@ -558,7 +539,7 @@ static void remove_rmap_item_from_tree(struct rmap_item *rmap_item) else ksm_pages_shared--; - drop_anon_vma(rmap_item); + ksm_drop_anon_vma(rmap_item); rmap_item->address &= PAGE_MASK; } else if (rmap_item->address & UNSTABLE_FLAG) { @@ -1566,7 +1547,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || @@ -1589,7 +1570,7 @@ again: if (!search_new_forks || !mapcount) break; } - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); if (!mapcount) goto out; } @@ -1619,7 +1600,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || @@ -1637,11 +1618,11 @@ again: ret = try_to_unmap_one(page, vma, rmap_item->address, flags); if (ret != SWAP_AGAIN || !page_mapped(page)) { - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); goto out; } } - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); } if (!search_new_forks++) goto again; @@ -1671,7 +1652,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || @@ -1688,11 +1669,11 @@ again: ret = rmap_one(page, vma, rmap_item->address, arg); if (ret != SWAP_AGAIN) { - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); goto out; } } - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); } if (!search_new_forks++) goto again; @@ -1943,15 +1924,11 @@ static int __init ksm_init(void) if (err) goto out; - err = mm_slots_hash_init(); - if (err) - goto out_free1; - ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd"); if (IS_ERR(ksm_thread)) { printk(KERN_ERR "ksm: creating kthread failed\n"); err = PTR_ERR(ksm_thread); - goto out_free2; + goto out_free; } #ifdef CONFIG_SYSFS @@ -1959,7 +1936,7 @@ static int __init ksm_init(void) if (err) { printk(KERN_ERR "ksm: register sysfs failed\n"); kthread_stop(ksm_thread); - goto out_free2; + goto out_free; } #else ksm_run = KSM_RUN_MERGE; /* no way for user to start it */ @@ -1975,9 +1952,7 @@ static int __init ksm_init(void) #endif return 0; -out_free2: - mm_slots_hash_free(); -out_free1: +out_free: ksm_slab_free(); out: return err; diff --git a/mm/memblock.c b/mm/memblock.c index 3024eb30fc2..43840b305ec 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -504,7 +504,7 @@ int __init memblock_is_reserved(u64 addr) int memblock_is_region_reserved(u64 base, u64 size) { - return memblock_overlaps_region(&memblock.reserved, base, size); + return memblock_overlaps_region(&memblock.reserved, base, size) >= 0; } /* diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 20a8193a7af..3eed583895a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -47,10 +47,13 @@ #include <linux/mm_inline.h> #include <linux/page_cgroup.h> #include <linux/cpu.h> +#include <linux/oom.h> #include "internal.h" #include <asm/uaccess.h> +#include <trace/events/vmscan.h> + struct cgroup_subsys mem_cgroup_subsys __read_mostly; #define MEM_CGROUP_RECLAIM_RETRIES 5 struct mem_cgroup *root_mem_cgroup __read_mostly; @@ -211,8 +214,6 @@ struct mem_cgroup { */ spinlock_t reclaim_param_lock; - int prev_priority; /* for recording reclaim priority */ - /* * While reclaiming in a hierarchy, we cache the last child we * reclaimed from. @@ -268,6 +269,7 @@ enum move_type { /* "mc" and its members are protected by cgroup_mutex */ static struct move_charge_struct { + spinlock_t lock; /* for from, to, moving_task */ struct mem_cgroup *from; struct mem_cgroup *to; unsigned long precharge; @@ -276,6 +278,7 @@ static struct move_charge_struct { struct task_struct *moving_task; /* a task moving charges */ wait_queue_head_t waitq; /* a waitq for other context */ } mc = { + .lock = __SPIN_LOCK_UNLOCKED(mc.lock), .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), }; @@ -836,12 +839,13 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) { int ret; struct mem_cgroup *curr = NULL; + struct task_struct *p; - task_lock(task); - rcu_read_lock(); - curr = try_get_mem_cgroup_from_mm(task->mm); - rcu_read_unlock(); - task_unlock(task); + p = find_lock_task_mm(task); + if (!p) + return 0; + curr = try_get_mem_cgroup_from_mm(p->mm); + task_unlock(p); if (!curr) return 0; /* @@ -858,35 +862,6 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) return ret; } -/* - * prev_priority control...this will be used in memory reclaim path. - */ -int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) -{ - int prev_priority; - - spin_lock(&mem->reclaim_param_lock); - prev_priority = mem->prev_priority; - spin_unlock(&mem->reclaim_param_lock); - - return prev_priority; -} - -void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) -{ - spin_lock(&mem->reclaim_param_lock); - if (priority < mem->prev_priority) - mem->prev_priority = priority; - spin_unlock(&mem->reclaim_param_lock); -} - -void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) -{ - spin_lock(&mem->reclaim_param_lock); - mem->prev_priority = priority; - spin_unlock(&mem->reclaim_param_lock); -} - static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) { unsigned long active; @@ -944,7 +919,7 @@ unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, struct zone *zone, enum lru_list lru) { - int nid = zone->zone_pgdat->node_id; + int nid = zone_to_nid(zone); int zid = zone_idx(zone); struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); @@ -954,7 +929,7 @@ unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, struct zone *zone) { - int nid = zone->zone_pgdat->node_id; + int nid = zone_to_nid(zone); int zid = zone_idx(zone); struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); @@ -999,7 +974,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, LIST_HEAD(pc_list); struct list_head *src; struct page_cgroup *pc, *tmp; - int nid = z->zone_pgdat->node_id; + int nid = zone_to_nid(z); int zid = zone_idx(z); struct mem_cgroup_per_zone *mz; int lru = LRU_FILE * file + active; @@ -1038,6 +1013,10 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, } *scanned = scan; + + trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken, + 0, 0, 0, mode); + return nr_taken; } @@ -1072,6 +1051,47 @@ static unsigned int get_swappiness(struct mem_cgroup *memcg) return swappiness; } +/* A routine for testing mem is not under move_account */ + +static bool mem_cgroup_under_move(struct mem_cgroup *mem) +{ + struct mem_cgroup *from; + struct mem_cgroup *to; + bool ret = false; + /* + * Unlike task_move routines, we access mc.to, mc.from not under + * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. + */ + spin_lock(&mc.lock); + from = mc.from; + to = mc.to; + if (!from) + goto unlock; + if (from == mem || to == mem + || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css)) + || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css))) + ret = true; +unlock: + spin_unlock(&mc.lock); + return ret; +} + +static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem) +{ + if (mc.moving_task && current != mc.moving_task) { + if (mem_cgroup_under_move(mem)) { + DEFINE_WAIT(wait); + prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); + /* moving charge context might have finished. */ + if (mc.moving_task) + schedule(); + finish_wait(&mc.waitq, &wait); + return true; + } + } + return false; +} + static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data) { int *val = data; @@ -1158,6 +1178,24 @@ static int mem_cgroup_count_children(struct mem_cgroup *mem) } /* + * Return the memory (and swap, if configured) limit for a memcg. + */ +u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) +{ + u64 limit; + u64 memsw; + + limit = res_counter_read_u64(&memcg->res, RES_LIMIT) + + total_swap_pages; + memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); + /* + * If memsw is finite and limits the amount of swap space available + * to this memcg, return that limit. + */ + return min(limit, memsw); +} + +/* * Visit the first child (need not be the first child as per the ordering * of the cgroup list, since we track last_scanned_child) of @mem and use * that to reclaim free pages from. @@ -1262,8 +1300,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, /* we use swappiness of local cgroup */ if (check_soft) ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, - noswap, get_swappiness(victim), zone, - zone->zone_pgdat->node_id); + noswap, get_swappiness(victim), zone); else ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap, get_swappiness(victim)); @@ -1370,7 +1407,7 @@ static void memcg_wakeup_oom(struct mem_cgroup *mem) static void memcg_oom_recover(struct mem_cgroup *mem) { - if (atomic_read(&mem->oom_lock)) + if (mem && atomic_read(&mem->oom_lock)) memcg_wakeup_oom(mem); } @@ -1582,16 +1619,83 @@ static int __cpuinit memcg_stock_cpu_callback(struct notifier_block *nb, return NOTIFY_OK; } + +/* See __mem_cgroup_try_charge() for details */ +enum { + CHARGE_OK, /* success */ + CHARGE_RETRY, /* need to retry but retry is not bad */ + CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ + CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ + CHARGE_OOM_DIE, /* the current is killed because of OOM */ +}; + +static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask, + int csize, bool oom_check) +{ + struct mem_cgroup *mem_over_limit; + struct res_counter *fail_res; + unsigned long flags = 0; + int ret; + + ret = res_counter_charge(&mem->res, csize, &fail_res); + + if (likely(!ret)) { + if (!do_swap_account) + return CHARGE_OK; + ret = res_counter_charge(&mem->memsw, csize, &fail_res); + if (likely(!ret)) + return CHARGE_OK; + + mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); + flags |= MEM_CGROUP_RECLAIM_NOSWAP; + } else + mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); + + if (csize > PAGE_SIZE) /* change csize and retry */ + return CHARGE_RETRY; + + if (!(gfp_mask & __GFP_WAIT)) + return CHARGE_WOULDBLOCK; + + ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, + gfp_mask, flags); + /* + * try_to_free_mem_cgroup_pages() might not give us a full + * picture of reclaim. Some pages are reclaimed and might be + * moved to swap cache or just unmapped from the cgroup. + * Check the limit again to see if the reclaim reduced the + * current usage of the cgroup before giving up + */ + if (ret || mem_cgroup_check_under_limit(mem_over_limit)) + return CHARGE_RETRY; + + /* + * At task move, charge accounts can be doubly counted. So, it's + * better to wait until the end of task_move if something is going on. + */ + if (mem_cgroup_wait_acct_move(mem_over_limit)) + return CHARGE_RETRY; + + /* If we don't need to call oom-killer at el, return immediately */ + if (!oom_check) + return CHARGE_NOMEM; + /* check OOM */ + if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask)) + return CHARGE_OOM_DIE; + + return CHARGE_RETRY; +} + /* * Unlike exported interface, "oom" parameter is added. if oom==true, * oom-killer can be invoked. */ static int __mem_cgroup_try_charge(struct mm_struct *mm, - gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom) + gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom) { - struct mem_cgroup *mem, *mem_over_limit; - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; - struct res_counter *fail_res; + int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; + struct mem_cgroup *mem = NULL; + int ret; int csize = CHARGE_SIZE; /* @@ -1609,126 +1713,108 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, * thread group leader migrates. It's possible that mm is not * set, if so charge the init_mm (happens for pagecache usage). */ - mem = *memcg; - if (likely(!mem)) { - mem = try_get_mem_cgroup_from_mm(mm); - *memcg = mem; - } else { - css_get(&mem->css); - } - if (unlikely(!mem)) - return 0; - - VM_BUG_ON(css_is_removed(&mem->css)); - if (mem_cgroup_is_root(mem)) - goto done; - - while (1) { - int ret = 0; - unsigned long flags = 0; - + if (!*memcg && !mm) + goto bypass; +again: + if (*memcg) { /* css should be a valid one */ + mem = *memcg; + VM_BUG_ON(css_is_removed(&mem->css)); + if (mem_cgroup_is_root(mem)) + goto done; if (consume_stock(mem)) goto done; + css_get(&mem->css); + } else { + struct task_struct *p; - ret = res_counter_charge(&mem->res, csize, &fail_res); - if (likely(!ret)) { - if (!do_swap_account) - break; - ret = res_counter_charge(&mem->memsw, csize, &fail_res); - if (likely(!ret)) - break; - /* mem+swap counter fails */ - res_counter_uncharge(&mem->res, csize); - flags |= MEM_CGROUP_RECLAIM_NOSWAP; - mem_over_limit = mem_cgroup_from_res_counter(fail_res, - memsw); - } else - /* mem counter fails */ - mem_over_limit = mem_cgroup_from_res_counter(fail_res, - res); - - /* reduce request size and retry */ - if (csize > PAGE_SIZE) { - csize = PAGE_SIZE; - continue; - } - if (!(gfp_mask & __GFP_WAIT)) - goto nomem; - - ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, - gfp_mask, flags); - if (ret) - continue; - + rcu_read_lock(); + p = rcu_dereference(mm->owner); + VM_BUG_ON(!p); /* - * try_to_free_mem_cgroup_pages() might not give us a full - * picture of reclaim. Some pages are reclaimed and might be - * moved to swap cache or just unmapped from the cgroup. - * Check the limit again to see if the reclaim reduced the - * current usage of the cgroup before giving up - * + * because we don't have task_lock(), "p" can exit while + * we're here. In that case, "mem" can point to root + * cgroup but never be NULL. (and task_struct itself is freed + * by RCU, cgroup itself is RCU safe.) Then, we have small + * risk here to get wrong cgroup. But such kind of mis-account + * by race always happens because we don't have cgroup_mutex(). + * It's overkill and we allow that small race, here. */ - if (mem_cgroup_check_under_limit(mem_over_limit)) - continue; - - /* try to avoid oom while someone is moving charge */ - if (mc.moving_task && current != mc.moving_task) { - struct mem_cgroup *from, *to; - bool do_continue = false; + mem = mem_cgroup_from_task(p); + VM_BUG_ON(!mem); + if (mem_cgroup_is_root(mem)) { + rcu_read_unlock(); + goto done; + } + if (consume_stock(mem)) { /* - * There is a small race that "from" or "to" can be - * freed by rmdir, so we use css_tryget(). + * It seems dagerous to access memcg without css_get(). + * But considering how consume_stok works, it's not + * necessary. If consume_stock success, some charges + * from this memcg are cached on this cpu. So, we + * don't need to call css_get()/css_tryget() before + * calling consume_stock(). */ - from = mc.from; - to = mc.to; - if (from && css_tryget(&from->css)) { - if (mem_over_limit->use_hierarchy) - do_continue = css_is_ancestor( - &from->css, - &mem_over_limit->css); - else - do_continue = (from == mem_over_limit); - css_put(&from->css); - } - if (!do_continue && to && css_tryget(&to->css)) { - if (mem_over_limit->use_hierarchy) - do_continue = css_is_ancestor( - &to->css, - &mem_over_limit->css); - else - do_continue = (to == mem_over_limit); - css_put(&to->css); - } - if (do_continue) { - DEFINE_WAIT(wait); - prepare_to_wait(&mc.waitq, &wait, - TASK_INTERRUPTIBLE); - /* moving charge context might have finished. */ - if (mc.moving_task) - schedule(); - finish_wait(&mc.waitq, &wait); - continue; - } + rcu_read_unlock(); + goto done; + } + /* after here, we may be blocked. we need to get refcnt */ + if (!css_tryget(&mem->css)) { + rcu_read_unlock(); + goto again; + } + rcu_read_unlock(); + } + + do { + bool oom_check; + + /* If killed, bypass charge */ + if (fatal_signal_pending(current)) { + css_put(&mem->css); + goto bypass; + } + + oom_check = false; + if (oom && !nr_oom_retries) { + oom_check = true; + nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; } - if (!nr_retries--) { - if (!oom) + ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check); + + switch (ret) { + case CHARGE_OK: + break; + case CHARGE_RETRY: /* not in OOM situation but retry */ + csize = PAGE_SIZE; + css_put(&mem->css); + mem = NULL; + goto again; + case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ + css_put(&mem->css); + goto nomem; + case CHARGE_NOMEM: /* OOM routine works */ + if (!oom) { + css_put(&mem->css); goto nomem; - if (mem_cgroup_handle_oom(mem_over_limit, gfp_mask)) { - nr_retries = MEM_CGROUP_RECLAIM_RETRIES; - continue; } - /* When we reach here, current task is dying .*/ + /* If oom, we never return -ENOMEM */ + nr_oom_retries--; + break; + case CHARGE_OOM_DIE: /* Killed by OOM Killer */ css_put(&mem->css); goto bypass; } - } + } while (ret != CHARGE_OK); + if (csize > PAGE_SIZE) refill_stock(mem, csize - PAGE_SIZE); + css_put(&mem->css); done: + *memcg = mem; return 0; nomem: - css_put(&mem->css); + *memcg = NULL; return -ENOMEM; bypass: *memcg = NULL; @@ -1747,11 +1833,7 @@ static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem, res_counter_uncharge(&mem->res, PAGE_SIZE * count); if (do_swap_account) res_counter_uncharge(&mem->memsw, PAGE_SIZE * count); - VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags)); - WARN_ON_ONCE(count > INT_MAX); - __css_put(&mem->css, (int)count); } - /* we don't need css_put for root */ } static void mem_cgroup_cancel_charge(struct mem_cgroup *mem) @@ -1979,10 +2061,9 @@ out: * < 0 if the cgroup is over its limit */ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, - gfp_t gfp_mask, enum charge_type ctype, - struct mem_cgroup *memcg) + gfp_t gfp_mask, enum charge_type ctype) { - struct mem_cgroup *mem; + struct mem_cgroup *mem = NULL; struct page_cgroup *pc; int ret; @@ -1992,7 +2073,6 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, return 0; prefetchw(pc); - mem = memcg; ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true); if (ret || !mem) return ret; @@ -2020,7 +2100,7 @@ int mem_cgroup_newpage_charge(struct page *page, if (unlikely(!mm)) mm = &init_mm; return mem_cgroup_charge_common(page, mm, gfp_mask, - MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); + MEM_CGROUP_CHARGE_TYPE_MAPPED); } static void @@ -2030,7 +2110,6 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) { - struct mem_cgroup *mem = NULL; int ret; if (mem_cgroup_disabled()) @@ -2051,7 +2130,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, if (!(gfp_mask & __GFP_WAIT)) { struct page_cgroup *pc; - pc = lookup_page_cgroup(page); if (!pc) return 0; @@ -2063,22 +2141,24 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, unlock_page_cgroup(pc); } - if (unlikely(!mm && !mem)) + if (unlikely(!mm)) mm = &init_mm; if (page_is_file_cache(page)) return mem_cgroup_charge_common(page, mm, gfp_mask, - MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); + MEM_CGROUP_CHARGE_TYPE_CACHE); /* shmem */ if (PageSwapCache(page)) { + struct mem_cgroup *mem = NULL; + ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); if (!ret) __mem_cgroup_commit_charge_swapin(page, mem, MEM_CGROUP_CHARGE_TYPE_SHMEM); } else ret = mem_cgroup_charge_common(page, mm, gfp_mask, - MEM_CGROUP_CHARGE_TYPE_SHMEM, mem); + MEM_CGROUP_CHARGE_TYPE_SHMEM); return ret; } @@ -2114,7 +2194,6 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm, goto charge_cur_mm; *ptr = mem; ret = __mem_cgroup_try_charge(NULL, mask, ptr, true); - /* drop extra refcnt from tryget */ css_put(&mem->css); return ret; charge_cur_mm: @@ -2245,7 +2324,6 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) { struct page_cgroup *pc; struct mem_cgroup *mem = NULL; - struct mem_cgroup_per_zone *mz; if (mem_cgroup_disabled()) return NULL; @@ -2285,10 +2363,6 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) break; } - if (!mem_cgroup_is_root(mem)) - __do_uncharge(mem, ctype); - if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) - mem_cgroup_swap_statistics(mem, true); mem_cgroup_charge_statistics(mem, pc, false); ClearPageCgroupUsed(pc); @@ -2299,13 +2373,18 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) * special functions. */ - mz = page_cgroup_zoneinfo(pc); unlock_page_cgroup(pc); - + /* + * even after unlock, we have mem->res.usage here and this memcg + * will never be freed. + */ memcg_check_events(mem, page); - /* at swapout, this memcg will be accessed to record to swap */ - if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) - css_put(&mem->css); + if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { + mem_cgroup_swap_statistics(mem, true); + mem_cgroup_get(mem); + } + if (!mem_cgroup_is_root(mem)) + __do_uncharge(mem, ctype); return mem; @@ -2392,13 +2471,12 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) memcg = __mem_cgroup_uncharge_common(page, ctype); - /* record memcg information */ - if (do_swap_account && swapout && memcg) { + /* + * record memcg information, if swapout && memcg != NULL, + * mem_cgroup_get() was called in uncharge(). + */ + if (do_swap_account && swapout && memcg) swap_cgroup_record(ent, css_id(&memcg->css)); - mem_cgroup_get(memcg); - } - if (swapout && memcg) - css_put(&memcg->css); } #endif @@ -2476,7 +2554,6 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry, */ if (!mem_cgroup_is_root(to)) res_counter_uncharge(&to->res, PAGE_SIZE); - css_put(&to->css); } return 0; } @@ -2611,11 +2688,8 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem, ClearPageCgroupMigration(pc); unlock_page_cgroup(pc); - if (unused != oldpage) - pc = lookup_page_cgroup(unused); __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE); - pc = lookup_page_cgroup(used); /* * If a page is a file cache, radix-tree replacement is very atomic * and we can skip this check. When it was an Anon page, its mapcount @@ -2791,8 +2865,7 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, } unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, - gfp_t gfp_mask, int nid, - int zid) + gfp_t gfp_mask) { unsigned long nr_reclaimed = 0; struct mem_cgroup_per_zone *mz, *next_mz = NULL; @@ -2804,7 +2877,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, if (order > 0) return 0; - mctz = soft_limit_tree_node_zone(nid, zid); + mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); /* * This loop can run a while, specially if mem_cgroup's continuously * keep exceeding their soft limit and putting the system under @@ -3759,8 +3832,6 @@ static int mem_cgroup_oom_control_read(struct cgroup *cgrp, return 0; } -/* - */ static int mem_cgroup_oom_control_write(struct cgroup *cgrp, struct cftype *cft, u64 val) { @@ -4180,9 +4251,6 @@ static int mem_cgroup_do_precharge(unsigned long count) goto one_by_one; } mc.precharge += count; - VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags)); - WARN_ON_ONCE(count > INT_MAX); - __css_get(&mem->css, (int)count); return ret; } one_by_one: @@ -4400,11 +4468,13 @@ static int mem_cgroup_precharge_mc(struct mm_struct *mm) static void mem_cgroup_clear_mc(void) { + struct mem_cgroup *from = mc.from; + struct mem_cgroup *to = mc.to; + /* we must uncharge all the leftover precharges from mc.to */ if (mc.precharge) { __mem_cgroup_cancel_charge(mc.to, mc.precharge); mc.precharge = 0; - memcg_oom_recover(mc.to); } /* * we didn't uncharge from mc.from at mem_cgroup_move_account(), so @@ -4413,11 +4483,9 @@ static void mem_cgroup_clear_mc(void) if (mc.moved_charge) { __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); mc.moved_charge = 0; - memcg_oom_recover(mc.from); } /* we must fixup refcnts and charges */ if (mc.moved_swap) { - WARN_ON_ONCE(mc.moved_swap > INT_MAX); /* uncharge swap account from the old cgroup */ if (!mem_cgroup_is_root(mc.from)) res_counter_uncharge(&mc.from->memsw, @@ -4431,16 +4499,18 @@ static void mem_cgroup_clear_mc(void) */ res_counter_uncharge(&mc.to->res, PAGE_SIZE * mc.moved_swap); - VM_BUG_ON(test_bit(CSS_ROOT, &mc.to->css.flags)); - __css_put(&mc.to->css, mc.moved_swap); } /* we've already done mem_cgroup_get(mc.to) */ mc.moved_swap = 0; } + spin_lock(&mc.lock); mc.from = NULL; mc.to = NULL; mc.moving_task = NULL; + spin_unlock(&mc.lock); + memcg_oom_recover(from); + memcg_oom_recover(to); wake_up_all(&mc.waitq); } @@ -4469,12 +4539,14 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss, VM_BUG_ON(mc.moved_charge); VM_BUG_ON(mc.moved_swap); VM_BUG_ON(mc.moving_task); + spin_lock(&mc.lock); mc.from = from; mc.to = mem; mc.precharge = 0; mc.moved_charge = 0; mc.moved_swap = 0; mc.moving_task = current; + spin_unlock(&mc.lock); ret = mem_cgroup_precharge_mc(mm); if (ret) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 6b44e52caca..9c26eeca134 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -46,6 +46,7 @@ #include <linux/suspend.h> #include <linux/slab.h> #include <linux/swapops.h> +#include <linux/hugetlb.h> #include "internal.h" int sysctl_memory_failure_early_kill __read_mostly = 0; @@ -690,17 +691,29 @@ static int me_swapcache_clean(struct page *p, unsigned long pfn) /* * Huge pages. Needs work. * Issues: - * No rmap support so we cannot find the original mapper. In theory could walk - * all MMs and look for the mappings, but that would be non atomic and racy. - * Need rmap for hugepages for this. Alternatively we could employ a heuristic, - * like just walking the current process and hoping it has it mapped (that - * should be usually true for the common "shared database cache" case) - * Should handle free huge pages and dequeue them too, but this needs to - * handle huge page accounting correctly. + * - Error on hugepage is contained in hugepage unit (not in raw page unit.) + * To narrow down kill region to one page, we need to break up pmd. + * - To support soft-offlining for hugepage, we need to support hugepage + * migration. */ static int me_huge_page(struct page *p, unsigned long pfn) { - return FAILED; + struct page *hpage = compound_head(p); + /* + * We can safely recover from error on free or reserved (i.e. + * not in-use) hugepage by dequeuing it from freelist. + * To check whether a hugepage is in-use or not, we can't use + * page->lru because it can be used in other hugepage operations, + * such as __unmap_hugepage_range() and gather_surplus_pages(). + * So instead we use page_mapping() and PageAnon(). + * We assume that this function is called with page lock held, + * so there is no race between isolation and mapping/unmapping. + */ + if (!(page_mapping(hpage) || PageAnon(hpage))) { + __isolate_hwpoisoned_huge_page(hpage); + return RECOVERED; + } + return DELAYED; } /* @@ -838,6 +851,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, int ret; int i; int kill = 1; + struct page *hpage = compound_head(p); if (PageReserved(p) || PageSlab(p)) return SWAP_SUCCESS; @@ -846,10 +860,10 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, * This check implies we don't kill processes if their pages * are in the swap cache early. Those are always late kills. */ - if (!page_mapped(p)) + if (!page_mapped(hpage)) return SWAP_SUCCESS; - if (PageCompound(p) || PageKsm(p)) + if (PageKsm(p)) return SWAP_FAIL; if (PageSwapCache(p)) { @@ -864,10 +878,11 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, * XXX: the dirty test could be racy: set_page_dirty() may not always * be called inside page lock (it's recommended but not enforced). */ - mapping = page_mapping(p); - if (!PageDirty(p) && mapping && mapping_cap_writeback_dirty(mapping)) { - if (page_mkclean(p)) { - SetPageDirty(p); + mapping = page_mapping(hpage); + if (!PageDirty(hpage) && mapping && + mapping_cap_writeback_dirty(mapping)) { + if (page_mkclean(hpage)) { + SetPageDirty(hpage); } else { kill = 0; ttu |= TTU_IGNORE_HWPOISON; @@ -886,14 +901,14 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, * there's nothing that can be done. */ if (kill) - collect_procs(p, &tokill); + collect_procs(hpage, &tokill); /* * try_to_unmap can fail temporarily due to races. * Try a few times (RED-PEN better strategy?) */ for (i = 0; i < N_UNMAP_TRIES; i++) { - ret = try_to_unmap(p, ttu); + ret = try_to_unmap(hpage, ttu); if (ret == SWAP_SUCCESS) break; pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn, ret); @@ -901,7 +916,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, if (ret != SWAP_SUCCESS) printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n", - pfn, page_mapcount(p)); + pfn, page_mapcount(hpage)); /* * Now that the dirty bit has been propagated to the @@ -912,17 +927,35 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, * use a more force-full uncatchable kill to prevent * any accesses to the poisoned memory. */ - kill_procs_ao(&tokill, !!PageDirty(p), trapno, + kill_procs_ao(&tokill, !!PageDirty(hpage), trapno, ret != SWAP_SUCCESS, pfn); return ret; } +static void set_page_hwpoison_huge_page(struct page *hpage) +{ + int i; + int nr_pages = 1 << compound_order(hpage); + for (i = 0; i < nr_pages; i++) + SetPageHWPoison(hpage + i); +} + +static void clear_page_hwpoison_huge_page(struct page *hpage) +{ + int i; + int nr_pages = 1 << compound_order(hpage); + for (i = 0; i < nr_pages; i++) + ClearPageHWPoison(hpage + i); +} + int __memory_failure(unsigned long pfn, int trapno, int flags) { struct page_state *ps; struct page *p; + struct page *hpage; int res; + unsigned int nr_pages; if (!sysctl_memory_failure_recovery) panic("Memory failure from trap %d on page %lx", trapno, pfn); @@ -935,12 +968,14 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) } p = pfn_to_page(pfn); + hpage = compound_head(p); if (TestSetPageHWPoison(p)) { printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn); return 0; } - atomic_long_add(1, &mce_bad_pages); + nr_pages = 1 << compound_order(hpage); + atomic_long_add(nr_pages, &mce_bad_pages); /* * We need/can do nothing about count=0 pages. @@ -954,7 +989,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) * that may make page_freeze_refs()/page_unfreeze_refs() mismatch. */ if (!(flags & MF_COUNT_INCREASED) && - !get_page_unless_zero(compound_head(p))) { + !get_page_unless_zero(hpage)) { if (is_free_buddy_page(p)) { action_result(pfn, "free buddy", DELAYED); return 0; @@ -972,9 +1007,9 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) * The check (unnecessarily) ignores LRU pages being isolated and * walked by the page reclaim code, however that's not a big loss. */ - if (!PageLRU(p)) + if (!PageLRU(p) && !PageHuge(p)) shake_page(p, 0); - if (!PageLRU(p)) { + if (!PageLRU(p) && !PageHuge(p)) { /* * shake_page could have turned it free. */ @@ -992,7 +1027,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) * It's very difficult to mess with pages currently under IO * and in many cases impossible, so we just avoid it here. */ - lock_page_nosync(p); + lock_page_nosync(hpage); /* * unpoison always clear PG_hwpoison inside page lock @@ -1004,11 +1039,31 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) } if (hwpoison_filter(p)) { if (TestClearPageHWPoison(p)) - atomic_long_dec(&mce_bad_pages); - unlock_page(p); - put_page(p); + atomic_long_sub(nr_pages, &mce_bad_pages); + unlock_page(hpage); + put_page(hpage); + return 0; + } + + /* + * For error on the tail page, we should set PG_hwpoison + * on the head page to show that the hugepage is hwpoisoned + */ + if (PageTail(p) && TestSetPageHWPoison(hpage)) { + action_result(pfn, "hugepage already hardware poisoned", + IGNORED); + unlock_page(hpage); + put_page(hpage); return 0; } + /* + * Set PG_hwpoison on all pages in an error hugepage, + * because containment is done in hugepage unit for now. + * Since we have done TestSetPageHWPoison() for the head page with + * page lock held, we can safely set PG_hwpoison bits on tail pages. + */ + if (PageHuge(p)) + set_page_hwpoison_huge_page(hpage); wait_on_page_writeback(p); @@ -1039,7 +1094,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) } } out: - unlock_page(p); + unlock_page(hpage); return res; } EXPORT_SYMBOL_GPL(__memory_failure); @@ -1083,6 +1138,7 @@ int unpoison_memory(unsigned long pfn) struct page *page; struct page *p; int freeit = 0; + unsigned int nr_pages; if (!pfn_valid(pfn)) return -ENXIO; @@ -1095,9 +1151,11 @@ int unpoison_memory(unsigned long pfn) return 0; } + nr_pages = 1 << compound_order(page); + if (!get_page_unless_zero(page)) { if (TestClearPageHWPoison(p)) - atomic_long_dec(&mce_bad_pages); + atomic_long_sub(nr_pages, &mce_bad_pages); pr_debug("MCE: Software-unpoisoned free page %#lx\n", pfn); return 0; } @@ -1109,11 +1167,13 @@ int unpoison_memory(unsigned long pfn) * the PG_hwpoison page will be caught and isolated on the entrance to * the free buddy page pool. */ - if (TestClearPageHWPoison(p)) { + if (TestClearPageHWPoison(page)) { pr_debug("MCE: Software-unpoisoned page %#lx\n", pfn); - atomic_long_dec(&mce_bad_pages); + atomic_long_sub(nr_pages, &mce_bad_pages); freeit = 1; } + if (PageHuge(p)) + clear_page_hwpoison_huge_page(page); unlock_page(page); put_page(page); diff --git a/mm/memory.c b/mm/memory.c index bde42c6d363..b6e5fd23cc5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -307,7 +307,6 @@ void free_pgd_range(struct mmu_gather *tlb, { pgd_t *pgd; unsigned long next; - unsigned long start; /* * The next few lines have given us lots of grief... @@ -351,7 +350,6 @@ void free_pgd_range(struct mmu_gather *tlb, if (addr > end - 1) return; - start = addr; pgd = pgd_offset(tlb->mm, addr); do { next = pgd_addr_end(addr, end); @@ -2008,11 +2006,10 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr, { pgd_t *pgd; unsigned long next; - unsigned long start = addr, end = addr + size; + unsigned long end = addr + size; int err; BUG_ON(addr >= end); - mmu_notifier_invalidate_range_start(mm, start, end); pgd = pgd_offset(mm, addr); do { next = pgd_addr_end(addr, end); @@ -2020,7 +2017,7 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr, if (err) break; } while (pgd++, addr = next, addr != end); - mmu_notifier_invalidate_range_end(mm, start, end); + return err; } EXPORT_SYMBOL_GPL(apply_to_page_range); @@ -2630,6 +2627,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, swp_entry_t entry; pte_t pte; struct mem_cgroup *ptr = NULL; + int exclusive = 0; int ret = 0; if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) @@ -2724,10 +2722,12 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) { pte = maybe_mkwrite(pte_mkdirty(pte), vma); flags &= ~FAULT_FLAG_WRITE; + ret |= VM_FAULT_WRITE; + exclusive = 1; } flush_icache_page(vma, page); set_pte_at(mm, address, page_table, pte); - page_add_anon_rmap(page, vma, address); + do_page_add_anon_rmap(page, vma, address, exclusive); /* It's better to call commit-charge after rmap is established */ mem_cgroup_commit_charge_swapin(page, ptr); @@ -2760,6 +2760,26 @@ out_release: } /* + * This is like a special single-page "expand_downwards()", + * except we must first make sure that 'address-PAGE_SIZE' + * doesn't hit another vma. + * + * The "find_vma()" will do the right thing even if we wrap + */ +static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned long address) +{ + address &= PAGE_MASK; + if ((vma->vm_flags & VM_GROWSDOWN) && address == vma->vm_start) { + address -= PAGE_SIZE; + if (find_vma(vma->vm_mm, address) != vma) + return -ENOMEM; + + expand_stack(vma, address); + } + return 0; +} + +/* * We enter with non-exclusive mmap_sem (to exclude vma changes, * but allow concurrent faults), and pte mapped but not yet locked. * We return with mmap_sem still held, but pte unmapped and unlocked. @@ -2772,19 +2792,23 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, spinlock_t *ptl; pte_t entry; + pte_unmap(page_table); + + /* Check if we need to add a guard page to the stack */ + if (check_stack_guard_page(vma, address) < 0) + return VM_FAULT_SIGBUS; + + /* Use the zero-page for reads */ if (!(flags & FAULT_FLAG_WRITE)) { entry = pte_mkspecial(pfn_pte(my_zero_pfn(address), vma->vm_page_prot)); - ptl = pte_lockptr(mm, pmd); - spin_lock(ptl); + page_table = pte_offset_map_lock(mm, pmd, address, &ptl); if (!pte_none(*page_table)) goto unlock; goto setpte; } /* Allocate our own private page. */ - pte_unmap(page_table); - if (unlikely(anon_vma_prepare(vma))) goto oom; page = alloc_zeroed_user_highpage_movable(vma, address); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 5bc0a96beb5..f969da5dd8a 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1275,33 +1275,42 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, const unsigned long __user *, new_nodes) { const struct cred *cred = current_cred(), *tcred; - struct mm_struct *mm; + struct mm_struct *mm = NULL; struct task_struct *task; - nodemask_t old; - nodemask_t new; nodemask_t task_nodes; int err; + nodemask_t *old; + nodemask_t *new; + NODEMASK_SCRATCH(scratch); + + if (!scratch) + return -ENOMEM; + + old = &scratch->mask1; + new = &scratch->mask2; - err = get_nodes(&old, old_nodes, maxnode); + err = get_nodes(old, old_nodes, maxnode); if (err) - return err; + goto out; - err = get_nodes(&new, new_nodes, maxnode); + err = get_nodes(new, new_nodes, maxnode); if (err) - return err; + goto out; /* Find the mm_struct */ read_lock(&tasklist_lock); task = pid ? find_task_by_vpid(pid) : current; if (!task) { read_unlock(&tasklist_lock); - return -ESRCH; + err = -ESRCH; + goto out; } mm = get_task_mm(task); read_unlock(&tasklist_lock); + err = -EINVAL; if (!mm) - return -EINVAL; + goto out; /* * Check if this process has the right to modify the specified @@ -1322,12 +1331,12 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, task_nodes = cpuset_mems_allowed(task); /* Is the user allowed to access the target nodes? */ - if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) { + if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) { err = -EPERM; goto out; } - if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) { + if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) { err = -EINVAL; goto out; } @@ -1336,10 +1345,13 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, if (err) goto out; - err = do_migrate_pages(mm, &old, &new, + err = do_migrate_pages(mm, old, new, capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); out: - mmput(mm); + if (mm) + mmput(mm); + NODEMASK_SCRATCH_FREE(scratch); + return err; } @@ -1712,6 +1724,50 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask) } #endif +/* + * mempolicy_nodemask_intersects + * + * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default + * policy. Otherwise, check for intersection between mask and the policy + * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local' + * policy, always return true since it may allocate elsewhere on fallback. + * + * Takes task_lock(tsk) to prevent freeing of its mempolicy. + */ +bool mempolicy_nodemask_intersects(struct task_struct *tsk, + const nodemask_t *mask) +{ + struct mempolicy *mempolicy; + bool ret = true; + + if (!mask) + return ret; + task_lock(tsk); + mempolicy = tsk->mempolicy; + if (!mempolicy) + goto out; + + switch (mempolicy->mode) { + case MPOL_PREFERRED: + /* + * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to + * allocate from, they may fallback to other nodes when oom. + * Thus, it's possible for tsk to have allocated memory from + * nodes in mask. + */ + break; + case MPOL_BIND: + case MPOL_INTERLEAVE: + ret = nodes_intersects(mempolicy->v.nodes, *mask); + break; + default: + BUG(); + } +out: + task_unlock(tsk); + return ret; +} + /* Allocate a page in interleaved policy. Own path because it needs to do special accounting. */ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, diff --git a/mm/migrate.c b/mm/migrate.c index 4205b1d6049..38e7cad782f 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -639,7 +639,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, * exist when the page is remapped later */ anon_vma = page_anon_vma(page); - atomic_inc(&anon_vma->external_refcount); + get_anon_vma(anon_vma); } } @@ -682,12 +682,8 @@ skip_unmap: rcu_unlock: /* Drop an anon_vma reference if we took one */ - if (anon_vma && atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->lock)) { - int empty = list_empty(&anon_vma->head); - spin_unlock(&anon_vma->lock); - if (empty) - anon_vma_free(anon_vma); - } + if (anon_vma) + drop_anon_vma(anon_vma); if (rcu_locked) rcu_read_unlock(); diff --git a/mm/mmap.c b/mm/mmap.c index e38e910cb75..31003338b97 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -452,12 +452,10 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma, spin_lock(&mapping->i_mmap_lock); vma->vm_truncate_count = mapping->truncate_count; } - anon_vma_lock(vma); __vma_link(mm, vma, prev, rb_link, rb_parent); __vma_link_file(vma); - anon_vma_unlock(vma); if (mapping) spin_unlock(&mapping->i_mmap_lock); @@ -506,6 +504,7 @@ int vma_adjust(struct vm_area_struct *vma, unsigned long start, struct vm_area_struct *importer = NULL; struct address_space *mapping = NULL; struct prio_tree_root *root = NULL; + struct anon_vma *anon_vma = NULL; struct file *file = vma->vm_file; long adjust_next = 0; int remove_next = 0; @@ -578,6 +577,17 @@ again: remove_next = 1 + (end > next->vm_end); } } + /* + * When changing only vma->vm_end, we don't really need anon_vma + * lock. This is a fairly rare case by itself, but the anon_vma + * lock may be shared between many sibling processes. Skipping + * the lock for brk adjustments makes a difference sometimes. + */ + if (vma->anon_vma && (insert || importer || start != vma->vm_start)) { + anon_vma = vma->anon_vma; + anon_vma_lock(anon_vma); + } + if (root) { flush_dcache_mmap_lock(mapping); vma_prio_tree_remove(vma, root); @@ -617,6 +627,8 @@ again: remove_next = 1 + (end > next->vm_end); __insert_vm_struct(mm, insert); } + if (anon_vma) + anon_vma_unlock(anon_vma); if (mapping) spin_unlock(&mapping->i_mmap_lock); @@ -1710,7 +1722,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) */ if (unlikely(anon_vma_prepare(vma))) return -ENOMEM; - anon_vma_lock(vma); + vma_lock_anon_vma(vma); /* * vma->vm_start/vm_end cannot change under us because the caller @@ -1721,7 +1733,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) if (address < PAGE_ALIGN(address+4)) address = PAGE_ALIGN(address+4); else { - anon_vma_unlock(vma); + vma_unlock_anon_vma(vma); return -ENOMEM; } error = 0; @@ -1739,7 +1751,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) perf_event_mmap(vma); } } - anon_vma_unlock(vma); + vma_unlock_anon_vma(vma); return error; } #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */ @@ -1764,7 +1776,7 @@ static int expand_downwards(struct vm_area_struct *vma, if (error) return error; - anon_vma_lock(vma); + vma_lock_anon_vma(vma); /* * vma->vm_start/vm_end cannot change under us because the caller @@ -1786,7 +1798,7 @@ static int expand_downwards(struct vm_area_struct *vma, perf_event_mmap(vma); } } - anon_vma_unlock(vma); + vma_unlock_anon_vma(vma); return error; } @@ -2470,23 +2482,23 @@ static DEFINE_MUTEX(mm_all_locks_mutex); static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) { - if (!test_bit(0, (unsigned long *) &anon_vma->head.next)) { + if (!test_bit(0, (unsigned long *) &anon_vma->root->head.next)) { /* * The LSB of head.next can't change from under us * because we hold the mm_all_locks_mutex. */ - spin_lock_nest_lock(&anon_vma->lock, &mm->mmap_sem); + spin_lock_nest_lock(&anon_vma->root->lock, &mm->mmap_sem); /* * We can safely modify head.next after taking the - * anon_vma->lock. If some other vma in this mm shares + * anon_vma->root->lock. If some other vma in this mm shares * the same anon_vma we won't take it again. * * No need of atomic instructions here, head.next * can't change from under us thanks to the - * anon_vma->lock. + * anon_vma->root->lock. */ if (__test_and_set_bit(0, (unsigned long *) - &anon_vma->head.next)) + &anon_vma->root->head.next)) BUG(); } } @@ -2577,7 +2589,7 @@ out_unlock: static void vm_unlock_anon_vma(struct anon_vma *anon_vma) { - if (test_bit(0, (unsigned long *) &anon_vma->head.next)) { + if (test_bit(0, (unsigned long *) &anon_vma->root->head.next)) { /* * The LSB of head.next can't change to 0 from under * us because we hold the mm_all_locks_mutex. @@ -2588,12 +2600,12 @@ static void vm_unlock_anon_vma(struct anon_vma *anon_vma) * * No need of atomic instructions here, head.next * can't change from under us until we release the - * anon_vma->lock. + * anon_vma->root->lock. */ if (!__test_and_clear_bit(0, (unsigned long *) - &anon_vma->head.next)) + &anon_vma->root->head.next)) BUG(); - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); } } diff --git a/mm/nommu.c b/mm/nommu.c index b76f3ee0abe..efa9a380335 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -36,11 +36,6 @@ #include <asm/mmu_context.h> #include "internal.h" -static inline __attribute__((format(printf, 1, 2))) -void no_printk(const char *fmt, ...) -{ -} - #if 0 #define kenter(FMT, ...) \ printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 709aedfaa01..5014e50644d 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -4,6 +4,8 @@ * Copyright (C) 1998,2000 Rik van Riel * Thanks go out to Claus Fischer for some serious inspiration and * for goading me into coding this file... + * Copyright (C) 2010 Google, Inc. + * Rewritten by David Rientjes * * The routines in this file are used to kill a process when * we're seriously out of memory. This gets called from __alloc_pages() @@ -27,171 +29,188 @@ #include <linux/module.h> #include <linux/notifier.h> #include <linux/memcontrol.h> +#include <linux/mempolicy.h> #include <linux/security.h> int sysctl_panic_on_oom; int sysctl_oom_kill_allocating_task; -int sysctl_oom_dump_tasks; +int sysctl_oom_dump_tasks = 1; static DEFINE_SPINLOCK(zone_scan_lock); -/* #define DEBUG */ + +#ifdef CONFIG_NUMA +/** + * has_intersects_mems_allowed() - check task eligiblity for kill + * @tsk: task struct of which task to consider + * @mask: nodemask passed to page allocator for mempolicy ooms + * + * Task eligibility is determined by whether or not a candidate task, @tsk, + * shares the same mempolicy nodes as current if it is bound by such a policy + * and whether or not it has the same set of allowed cpuset nodes. + */ +static bool has_intersects_mems_allowed(struct task_struct *tsk, + const nodemask_t *mask) +{ + struct task_struct *start = tsk; + + do { + if (mask) { + /* + * If this is a mempolicy constrained oom, tsk's + * cpuset is irrelevant. Only return true if its + * mempolicy intersects current, otherwise it may be + * needlessly killed. + */ + if (mempolicy_nodemask_intersects(tsk, mask)) + return true; + } else { + /* + * This is not a mempolicy constrained oom, so only + * check the mems of tsk's cpuset. + */ + if (cpuset_mems_allowed_intersects(current, tsk)) + return true; + } + } while_each_thread(start, tsk); + + return false; +} +#else +static bool has_intersects_mems_allowed(struct task_struct *tsk, + const nodemask_t *mask) +{ + return true; +} +#endif /* CONFIG_NUMA */ /* - * Is all threads of the target process nodes overlap ours? + * If this is a system OOM (not a memcg OOM) and the task selected to be + * killed is not already running at high (RT) priorities, speed up the + * recovery by boosting the dying task to the lowest FIFO priority. + * That helps with the recovery and avoids interfering with RT tasks. */ -static int has_intersects_mems_allowed(struct task_struct *tsk) +static void boost_dying_task_prio(struct task_struct *p, + struct mem_cgroup *mem) { - struct task_struct *t; + struct sched_param param = { .sched_priority = 1 }; + + if (mem) + return; + + if (!rt_task(p)) + sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m); +} + +/* + * The process p may have detached its own ->mm while exiting or through + * use_mm(), but one or more of its subthreads may still have a valid + * pointer. Return p, or any of its subthreads with a valid ->mm, with + * task_lock() held. + */ +struct task_struct *find_lock_task_mm(struct task_struct *p) +{ + struct task_struct *t = p; - t = tsk; do { - if (cpuset_mems_allowed_intersects(current, t)) - return 1; - t = next_thread(t); - } while (t != tsk); + task_lock(t); + if (likely(t->mm)) + return t; + task_unlock(t); + } while_each_thread(p, t); - return 0; + return NULL; +} + +/* return true if the task is not adequate as candidate victim task. */ +static bool oom_unkillable_task(struct task_struct *p, struct mem_cgroup *mem, + const nodemask_t *nodemask) +{ + if (is_global_init(p)) + return true; + if (p->flags & PF_KTHREAD) + return true; + + /* When mem_cgroup_out_of_memory() and p is not member of the group */ + if (mem && !task_in_mem_cgroup(p, mem)) + return true; + + /* p may not have freeable memory in nodemask */ + if (!has_intersects_mems_allowed(p, nodemask)) + return true; + + return false; } /** - * badness - calculate a numeric value for how bad this task has been + * oom_badness - heuristic function to determine which candidate task to kill * @p: task struct of which task we should calculate - * @uptime: current uptime in seconds - * - * The formula used is relatively simple and documented inline in the - * function. The main rationale is that we want to select a good task - * to kill when we run out of memory. + * @totalpages: total present RAM allowed for page allocation * - * Good in this context means that: - * 1) we lose the minimum amount of work done - * 2) we recover a large amount of memory - * 3) we don't kill anything innocent of eating tons of memory - * 4) we want to kill the minimum amount of processes (one) - * 5) we try to kill the process the user expects us to kill, this - * algorithm has been meticulously tuned to meet the principle - * of least surprise ... (be careful when you change it) + * The heuristic for determining which task to kill is made to be as simple and + * predictable as possible. The goal is to return the highest value for the + * task consuming the most memory to avoid subsequent oom failures. */ - -unsigned long badness(struct task_struct *p, unsigned long uptime) +unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem, + const nodemask_t *nodemask, unsigned long totalpages) { - unsigned long points, cpu_time, run_time; - struct mm_struct *mm; - struct task_struct *child; - int oom_adj = p->signal->oom_adj; - struct task_cputime task_time; - unsigned long utime; - unsigned long stime; + int points; - if (oom_adj == OOM_DISABLE) + if (oom_unkillable_task(p, mem, nodemask)) return 0; - task_lock(p); - mm = p->mm; - if (!mm) { - task_unlock(p); + p = find_lock_task_mm(p); + if (!p) return 0; - } - - /* - * The memory size of the process is the basis for the badness. - */ - points = mm->total_vm; /* - * After this unlock we can no longer dereference local variable `mm' + * Shortcut check for OOM_SCORE_ADJ_MIN so the entire heuristic doesn't + * need to be executed for something that cannot be killed. */ - task_unlock(p); - - /* - * swapoff can easily use up all memory, so kill those first. - */ - if (p->flags & PF_OOM_ORIGIN) - return ULONG_MAX; - - /* - * Processes which fork a lot of child processes are likely - * a good choice. We add half the vmsize of the children if they - * have an own mm. This prevents forking servers to flood the - * machine with an endless amount of children. In case a single - * child is eating the vast majority of memory, adding only half - * to the parents will make the child our kill candidate of choice. - */ - list_for_each_entry(child, &p->children, sibling) { - task_lock(child); - if (child->mm != mm && child->mm) - points += child->mm->total_vm/2 + 1; - task_unlock(child); + if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { + task_unlock(p); + return 0; } /* - * CPU time is in tens of seconds and run time is in thousands - * of seconds. There is no particular reason for this other than - * that it turned out to work very well in practice. - */ - thread_group_cputime(p, &task_time); - utime = cputime_to_jiffies(task_time.utime); - stime = cputime_to_jiffies(task_time.stime); - cpu_time = (utime + stime) >> (SHIFT_HZ + 3); - - - if (uptime >= p->start_time.tv_sec) - run_time = (uptime - p->start_time.tv_sec) >> 10; - else - run_time = 0; - - if (cpu_time) - points /= int_sqrt(cpu_time); - if (run_time) - points /= int_sqrt(int_sqrt(run_time)); - - /* - * Niced processes are most likely less important, so double - * their badness points. + * When the PF_OOM_ORIGIN bit is set, it indicates the task should have + * priority for oom killing. */ - if (task_nice(p) > 0) - points *= 2; + if (p->flags & PF_OOM_ORIGIN) { + task_unlock(p); + return 1000; + } /* - * Superuser processes are usually more important, so we make it - * less likely that we kill those. + * The memory controller may have a limit of 0 bytes, so avoid a divide + * by zero, if necessary. */ - if (has_capability_noaudit(p, CAP_SYS_ADMIN) || - has_capability_noaudit(p, CAP_SYS_RESOURCE)) - points /= 4; + if (!totalpages) + totalpages = 1; /* - * We don't want to kill a process with direct hardware access. - * Not only could that mess up the hardware, but usually users - * tend to only have this flag set on applications they think - * of as important. + * The baseline for the badness score is the proportion of RAM that each + * task's rss and swap space use. */ - if (has_capability_noaudit(p, CAP_SYS_RAWIO)) - points /= 4; + points = (get_mm_rss(p->mm) + get_mm_counter(p->mm, MM_SWAPENTS)) * 1000 / + totalpages; + task_unlock(p); /* - * If p's nodes don't overlap ours, it may still help to kill p - * because p may have allocated or otherwise mapped memory on - * this node before. However it will be less likely. + * Root processes get 3% bonus, just like the __vm_enough_memory() + * implementation used by LSMs. */ - if (!has_intersects_mems_allowed(p)) - points /= 8; + if (has_capability_noaudit(p, CAP_SYS_ADMIN)) + points -= 30; /* - * Adjust the score by oom_adj. + * /proc/pid/oom_score_adj ranges from -1000 to +1000 such that it may + * either completely disable oom killing or always prefer a certain + * task. */ - if (oom_adj) { - if (oom_adj > 0) { - if (!points) - points = 1; - points <<= oom_adj; - } else - points >>= -(oom_adj); - } + points += p->signal->oom_score_adj; -#ifdef DEBUG - printk(KERN_DEBUG "OOMkill: task %d (%s) got %lu points\n", - p->pid, p->comm, points); -#endif - return points; + if (points < 0) + return 0; + return (points < 1000) ? points : 1000; } /* @@ -199,12 +218,20 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) */ #ifdef CONFIG_NUMA static enum oom_constraint constrained_alloc(struct zonelist *zonelist, - gfp_t gfp_mask, nodemask_t *nodemask) + gfp_t gfp_mask, nodemask_t *nodemask, + unsigned long *totalpages) { struct zone *zone; struct zoneref *z; enum zone_type high_zoneidx = gfp_zone(gfp_mask); + bool cpuset_limited = false; + int nid; + + /* Default to all available memory */ + *totalpages = totalram_pages + total_swap_pages; + if (!zonelist) + return CONSTRAINT_NONE; /* * Reach here only when __GFP_NOFAIL is used. So, we should avoid * to kill current.We have to random task kill in this case. @@ -214,26 +241,37 @@ static enum oom_constraint constrained_alloc(struct zonelist *zonelist, return CONSTRAINT_NONE; /* - * The nodemask here is a nodemask passed to alloc_pages(). Now, - * cpuset doesn't use this nodemask for its hardwall/softwall/hierarchy - * feature. mempolicy is an only user of nodemask here. - * check mempolicy's nodemask contains all N_HIGH_MEMORY + * This is not a __GFP_THISNODE allocation, so a truncated nodemask in + * the page allocator means a mempolicy is in effect. Cpuset policy + * is enforced in get_page_from_freelist(). */ - if (nodemask && !nodes_subset(node_states[N_HIGH_MEMORY], *nodemask)) + if (nodemask && !nodes_subset(node_states[N_HIGH_MEMORY], *nodemask)) { + *totalpages = total_swap_pages; + for_each_node_mask(nid, *nodemask) + *totalpages += node_spanned_pages(nid); return CONSTRAINT_MEMORY_POLICY; + } /* Check this allocation failure is caused by cpuset's wall function */ for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx, nodemask) if (!cpuset_zone_allowed_softwall(zone, gfp_mask)) - return CONSTRAINT_CPUSET; + cpuset_limited = true; + if (cpuset_limited) { + *totalpages = total_swap_pages; + for_each_node_mask(nid, cpuset_current_mems_allowed) + *totalpages += node_spanned_pages(nid); + return CONSTRAINT_CPUSET; + } return CONSTRAINT_NONE; } #else static enum oom_constraint constrained_alloc(struct zonelist *zonelist, - gfp_t gfp_mask, nodemask_t *nodemask) + gfp_t gfp_mask, nodemask_t *nodemask, + unsigned long *totalpages) { + *totalpages = totalram_pages + total_swap_pages; return CONSTRAINT_NONE; } #endif @@ -244,28 +282,18 @@ static enum oom_constraint constrained_alloc(struct zonelist *zonelist, * * (not docbooked, we don't want this one cluttering up the manual) */ -static struct task_struct *select_bad_process(unsigned long *ppoints, - struct mem_cgroup *mem) +static struct task_struct *select_bad_process(unsigned int *ppoints, + unsigned long totalpages, struct mem_cgroup *mem, + const nodemask_t *nodemask) { struct task_struct *p; struct task_struct *chosen = NULL; - struct timespec uptime; *ppoints = 0; - do_posix_clock_monotonic_gettime(&uptime); for_each_process(p) { - unsigned long points; + unsigned int points; - /* - * skip kernel threads and tasks which have already released - * their mm. - */ - if (!p->mm) - continue; - /* skip the init task */ - if (is_global_init(p)) - continue; - if (mem && !task_in_mem_cgroup(p, mem)) + if (oom_unkillable_task(p, mem, nodemask)) continue; /* @@ -290,19 +318,16 @@ static struct task_struct *select_bad_process(unsigned long *ppoints, * the process of exiting and releasing its resources. * Otherwise we could get an easy OOM deadlock. */ - if (p->flags & PF_EXITING) { + if (thread_group_empty(p) && (p->flags & PF_EXITING) && p->mm) { if (p != current) return ERR_PTR(-1UL); chosen = p; - *ppoints = ULONG_MAX; + *ppoints = 1000; } - if (p->signal->oom_adj == OOM_DISABLE) - continue; - - points = badness(p, uptime.tv_sec); - if (points > *ppoints || !chosen) { + points = oom_badness(p, mem, nodemask, totalpages); + if (points > *ppoints) { chosen = p; *ppoints = points; } @@ -313,11 +338,11 @@ static struct task_struct *select_bad_process(unsigned long *ppoints, /** * dump_tasks - dump current memory state of all system tasks - * @mem: target memory controller + * @mem: current's memory controller, if constrained * * Dumps the current memory state of all system tasks, excluding kernel threads. * State information includes task's pid, uid, tgid, vm size, rss, cpu, oom_adj - * score, and name. + * value, oom_score_adj value, and name. * * If the actual is non-NULL, only tasks that are a member of the mem_cgroup are * shown. @@ -326,44 +351,43 @@ static struct task_struct *select_bad_process(unsigned long *ppoints, */ static void dump_tasks(const struct mem_cgroup *mem) { - struct task_struct *g, *p; - - printk(KERN_INFO "[ pid ] uid tgid total_vm rss cpu oom_adj " - "name\n"); - do_each_thread(g, p) { - struct mm_struct *mm; + struct task_struct *p; + struct task_struct *task; - if (mem && !task_in_mem_cgroup(p, mem)) + pr_info("[ pid ] uid tgid total_vm rss cpu oom_adj oom_score_adj name\n"); + for_each_process(p) { + if (p->flags & PF_KTHREAD) continue; - if (!thread_group_leader(p)) + if (mem && !task_in_mem_cgroup(p, mem)) continue; - task_lock(p); - mm = p->mm; - if (!mm) { + task = find_lock_task_mm(p); + if (!task) { /* - * total_vm and rss sizes do not exist for tasks with no - * mm so there's no need to report them; they can't be - * oom killed anyway. + * This is a kthread or all of p's threads have already + * detached their mm's. There's no need to report + * them; they can't be oom killed anyway. */ - task_unlock(p); continue; } - printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n", - p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm, - get_mm_rss(mm), (int)task_cpu(p), p->signal->oom_adj, - p->comm); - task_unlock(p); - } while_each_thread(g, p); + + pr_info("[%5d] %5d %5d %8lu %8lu %3u %3d %5d %s\n", + task->pid, __task_cred(task)->uid, task->tgid, + task->mm->total_vm, get_mm_rss(task->mm), + task_cpu(task), task->signal->oom_adj, + task->signal->oom_score_adj, task->comm); + task_unlock(task); + } } static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order, struct mem_cgroup *mem) { - pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, " - "oom_adj=%d\n", - current->comm, gfp_mask, order, current->signal->oom_adj); task_lock(current); + pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, " + "oom_adj=%d, oom_score_adj=%d\n", + current->comm, gfp_mask, order, current->signal->oom_adj, + current->signal->oom_score_adj); cpuset_print_task_mems_allowed(current); task_unlock(current); dump_stack(); @@ -374,72 +398,43 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order, } #define K(x) ((x) << (PAGE_SHIFT-10)) - -/* - * Send SIGKILL to the selected process irrespective of CAP_SYS_RAW_IO - * flag though it's unlikely that we select a process with CAP_SYS_RAW_IO - * set. - */ -static void __oom_kill_task(struct task_struct *p, int verbose) +static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem) { - if (is_global_init(p)) { - WARN_ON(1); - printk(KERN_WARNING "tried to kill init!\n"); - return; - } - - task_lock(p); - if (!p->mm) { - WARN_ON(1); - printk(KERN_WARNING "tried to kill an mm-less task %d (%s)!\n", - task_pid_nr(p), p->comm); + p = find_lock_task_mm(p); + if (!p) { task_unlock(p); - return; + return 1; } - - if (verbose) - printk(KERN_ERR "Killed process %d (%s) " - "vsz:%lukB, anon-rss:%lukB, file-rss:%lukB\n", - task_pid_nr(p), p->comm, - K(p->mm->total_vm), - K(get_mm_counter(p->mm, MM_ANONPAGES)), - K(get_mm_counter(p->mm, MM_FILEPAGES))); + pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n", + task_pid_nr(p), p->comm, K(p->mm->total_vm), + K(get_mm_counter(p->mm, MM_ANONPAGES)), + K(get_mm_counter(p->mm, MM_FILEPAGES))); task_unlock(p); + + set_tsk_thread_flag(p, TIF_MEMDIE); + force_sig(SIGKILL, p); + /* * We give our sacrificial lamb high priority and access to * all the memory it needs. That way it should be able to * exit() and clear out its resources quickly... */ - p->rt.time_slice = HZ; - set_tsk_thread_flag(p, TIF_MEMDIE); - - force_sig(SIGKILL, p); -} - -static int oom_kill_task(struct task_struct *p) -{ - /* WARNING: mm may not be dereferenced since we did not obtain its - * value from get_task_mm(p). This is OK since all we need to do is - * compare mm to q->mm below. - * - * Furthermore, even if mm contains a non-NULL value, p->mm may - * change to NULL at any time since we do not hold task_lock(p). - * However, this is of no concern to us. - */ - if (!p->mm || p->signal->oom_adj == OOM_DISABLE) - return 1; - - __oom_kill_task(p, 1); + boost_dying_task_prio(p, mem); return 0; } +#undef K static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, - unsigned long points, struct mem_cgroup *mem, + unsigned int points, unsigned long totalpages, + struct mem_cgroup *mem, nodemask_t *nodemask, const char *message) { - struct task_struct *c; + struct task_struct *victim = p; + struct task_struct *child; + struct task_struct *t = p; + unsigned int victim_points = 0; if (printk_ratelimit()) dump_header(p, gfp_mask, order, mem); @@ -449,40 +444,81 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, * its children or threads, just set TIF_MEMDIE so it can die quickly */ if (p->flags & PF_EXITING) { - __oom_kill_task(p, 0); + set_tsk_thread_flag(p, TIF_MEMDIE); + boost_dying_task_prio(p, mem); return 0; } - printk(KERN_ERR "%s: kill process %d (%s) score %li or a child\n", - message, task_pid_nr(p), p->comm, points); + task_lock(p); + pr_err("%s: Kill process %d (%s) score %d or sacrifice child\n", + message, task_pid_nr(p), p->comm, points); + task_unlock(p); - /* Try to kill a child first */ - list_for_each_entry(c, &p->children, sibling) { - if (c->mm == p->mm) - continue; - if (mem && !task_in_mem_cgroup(c, mem)) - continue; - if (!oom_kill_task(c)) - return 0; + /* + * If any of p's children has a different mm and is eligible for kill, + * the one with the highest badness() score is sacrificed for its + * parent. This attempts to lose the minimal amount of work done while + * still freeing memory. + */ + do { + list_for_each_entry(child, &t->children, sibling) { + unsigned int child_points; + + /* + * oom_badness() returns 0 if the thread is unkillable + */ + child_points = oom_badness(child, mem, nodemask, + totalpages); + if (child_points > victim_points) { + victim = child; + victim_points = child_points; + } + } + } while_each_thread(p, t); + + return oom_kill_task(victim, mem); +} + +/* + * Determines whether the kernel must panic because of the panic_on_oom sysctl. + */ +static void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask, + int order) +{ + if (likely(!sysctl_panic_on_oom)) + return; + if (sysctl_panic_on_oom != 2) { + /* + * panic_on_oom == 1 only affects CONSTRAINT_NONE, the kernel + * does not panic for cpuset, mempolicy, or memcg allocation + * failures. + */ + if (constraint != CONSTRAINT_NONE) + return; } - return oom_kill_task(p); + read_lock(&tasklist_lock); + dump_header(NULL, gfp_mask, order, NULL); + read_unlock(&tasklist_lock); + panic("Out of memory: %s panic_on_oom is enabled\n", + sysctl_panic_on_oom == 2 ? "compulsory" : "system-wide"); } #ifdef CONFIG_CGROUP_MEM_RES_CTLR void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask) { - unsigned long points = 0; + unsigned long limit; + unsigned int points = 0; struct task_struct *p; - if (sysctl_panic_on_oom == 2) - panic("out of memory(memcg). panic_on_oom is selected.\n"); + check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, 0); + limit = mem_cgroup_get_limit(mem) >> PAGE_SHIFT; read_lock(&tasklist_lock); retry: - p = select_bad_process(&points, mem); + p = select_bad_process(&points, limit, mem, NULL); if (!p || PTR_ERR(p) == -1UL) goto out; - if (oom_kill_process(p, gfp_mask, 0, points, mem, + if (oom_kill_process(p, gfp_mask, 0, points, limit, mem, NULL, "Memory cgroup out of memory")) goto retry; out: @@ -509,7 +545,7 @@ EXPORT_SYMBOL_GPL(unregister_oom_notifier); * if a parallel OOM killing is already taking place that includes a zone in * the zonelist. Otherwise, locks all zones in the zonelist and returns 1. */ -int try_set_zone_oom(struct zonelist *zonelist, gfp_t gfp_mask) +int try_set_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask) { struct zoneref *z; struct zone *zone; @@ -526,7 +562,7 @@ int try_set_zone_oom(struct zonelist *zonelist, gfp_t gfp_mask) for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) { /* * Lock each zone in the zonelist under zone_scan_lock so a - * parallel invocation of try_set_zone_oom() doesn't succeed + * parallel invocation of try_set_zonelist_oom() doesn't succeed * when it shouldn't. */ zone_set_flag(zone, ZONE_OOM_LOCKED); @@ -555,65 +591,40 @@ void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask) } /* - * Must be called with tasklist_lock held for read. + * Try to acquire the oom killer lock for all system zones. Returns zero if a + * parallel oom killing is taking place, otherwise locks all zones and returns + * non-zero. */ -static void __out_of_memory(gfp_t gfp_mask, int order) +static int try_set_system_oom(void) { - struct task_struct *p; - unsigned long points; - - if (sysctl_oom_kill_allocating_task) - if (!oom_kill_process(current, gfp_mask, order, 0, NULL, - "Out of memory (oom_kill_allocating_task)")) - return; -retry: - /* - * Rambo mode: Shoot down a process and hope it solves whatever - * issues we may have. - */ - p = select_bad_process(&points, NULL); - - if (PTR_ERR(p) == -1UL) - return; - - /* Found nothing?!?! Either we hang forever, or we panic. */ - if (!p) { - read_unlock(&tasklist_lock); - dump_header(NULL, gfp_mask, order, NULL); - panic("Out of memory and no killable processes...\n"); - } + struct zone *zone; + int ret = 1; - if (oom_kill_process(p, gfp_mask, order, points, NULL, - "Out of memory")) - goto retry; + spin_lock(&zone_scan_lock); + for_each_populated_zone(zone) + if (zone_is_oom_locked(zone)) { + ret = 0; + goto out; + } + for_each_populated_zone(zone) + zone_set_flag(zone, ZONE_OOM_LOCKED); +out: + spin_unlock(&zone_scan_lock); + return ret; } /* - * pagefault handler calls into here because it is out of memory but - * doesn't know exactly how or why. + * Clears ZONE_OOM_LOCKED for all system zones so that failed allocation + * attempts or page faults may now recall the oom killer, if necessary. */ -void pagefault_out_of_memory(void) +static void clear_system_oom(void) { - unsigned long freed = 0; - - blocking_notifier_call_chain(&oom_notify_list, 0, &freed); - if (freed > 0) - /* Got some memory back in the last second. */ - return; - - if (sysctl_panic_on_oom) - panic("out of memory from page fault. panic_on_oom is selected.\n"); - - read_lock(&tasklist_lock); - __out_of_memory(0, 0); /* unknown gfp_mask and order */ - read_unlock(&tasklist_lock); + struct zone *zone; - /* - * Give "p" a good chance of killing itself before we - * retry to allocate memory. - */ - if (!test_thread_flag(TIF_MEMDIE)) - schedule_timeout_uninterruptible(1); + spin_lock(&zone_scan_lock); + for_each_populated_zone(zone) + zone_clear_flag(zone, ZONE_OOM_LOCKED); + spin_unlock(&zone_scan_lock); } /** @@ -621,6 +632,7 @@ void pagefault_out_of_memory(void) * @zonelist: zonelist pointer * @gfp_mask: memory allocation flags * @order: amount of memory being requested as a power of 2 + * @nodemask: nodemask passed to page allocator * * If we run out of memory, we have the choice between either * killing a random task (bad), letting the system crash (worse) @@ -630,43 +642,68 @@ void pagefault_out_of_memory(void) void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order, nodemask_t *nodemask) { + struct task_struct *p; + unsigned long totalpages; unsigned long freed = 0; - enum oom_constraint constraint; + unsigned int points; + enum oom_constraint constraint = CONSTRAINT_NONE; blocking_notifier_call_chain(&oom_notify_list, 0, &freed); if (freed > 0) /* Got some memory back in the last second. */ return; - if (sysctl_panic_on_oom == 2) { - dump_header(NULL, gfp_mask, order, NULL); - panic("out of memory. Compulsory panic_on_oom is selected.\n"); + /* + * If current has a pending SIGKILL, then automatically select it. The + * goal is to allow it to allocate so that it may quickly exit and free + * its memory. + */ + if (fatal_signal_pending(current)) { + set_thread_flag(TIF_MEMDIE); + boost_dying_task_prio(current, NULL); + return; } /* * Check if there were limitations on the allocation (only relevant for * NUMA) that may require different handling. */ - constraint = constrained_alloc(zonelist, gfp_mask, nodemask); + constraint = constrained_alloc(zonelist, gfp_mask, nodemask, + &totalpages); + check_panic_on_oom(constraint, gfp_mask, order); + read_lock(&tasklist_lock); + if (sysctl_oom_kill_allocating_task && + !oom_unkillable_task(current, NULL, nodemask) && + (current->signal->oom_adj != OOM_DISABLE)) { + /* + * oom_kill_process() needs tasklist_lock held. If it returns + * non-zero, current could not be killed so we must fallback to + * the tasklist scan. + */ + if (!oom_kill_process(current, gfp_mask, order, 0, totalpages, + NULL, nodemask, + "Out of memory (oom_kill_allocating_task)")) + return; + } - switch (constraint) { - case CONSTRAINT_MEMORY_POLICY: - oom_kill_process(current, gfp_mask, order, 0, NULL, - "No available memory (MPOL_BIND)"); - break; +retry: + p = select_bad_process(&points, totalpages, NULL, + constraint == CONSTRAINT_MEMORY_POLICY ? nodemask : + NULL); + if (PTR_ERR(p) == -1UL) + return; - case CONSTRAINT_NONE: - if (sysctl_panic_on_oom) { - dump_header(NULL, gfp_mask, order, NULL); - panic("out of memory. panic_on_oom is selected\n"); - } - /* Fall-through */ - case CONSTRAINT_CPUSET: - __out_of_memory(gfp_mask, order); - break; + /* Found nothing?!?! Either we hang forever, or we panic. */ + if (!p) { + dump_header(NULL, gfp_mask, order, NULL); + read_unlock(&tasklist_lock); + panic("Out of memory and no killable processes...\n"); } + if (oom_kill_process(p, gfp_mask, order, points, totalpages, NULL, + nodemask, "Out of memory")) + goto retry; read_unlock(&tasklist_lock); /* @@ -676,3 +713,19 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, if (!test_thread_flag(TIF_MEMDIE)) schedule_timeout_uninterruptible(1); } + +/* + * The pagefault handler calls here because it is out of memory, so kill a + * memory-hogging task. If a populated zone has ZONE_OOM_LOCKED set, a parallel + * oom killing is already in progress so do nothing. If a task is found with + * TIF_MEMDIE set, it has been killed so do nothing and allow it to exit. + */ +void pagefault_out_of_memory(void) +{ + if (try_set_system_oom()) { + out_of_memory(NULL, 0, 0, NULL); + clear_system_oom(); + } + if (!test_thread_flag(TIF_MEMDIE)) + schedule_timeout_uninterruptible(1); +} diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 37498ef6154..20890d80c7e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -34,6 +34,7 @@ #include <linux/syscalls.h> #include <linux/buffer_head.h> #include <linux/pagevec.h> +#include <trace/events/writeback.h> /* * After a CPU has dirtied this many pages, balance_dirty_pages_ratelimited @@ -252,32 +253,6 @@ static void bdi_writeout_fraction(struct backing_dev_info *bdi, } } -/* - * Clip the earned share of dirty pages to that which is actually available. - * This avoids exceeding the total dirty_limit when the floating averages - * fluctuate too quickly. - */ -static void clip_bdi_dirty_limit(struct backing_dev_info *bdi, - unsigned long dirty, unsigned long *pbdi_dirty) -{ - unsigned long avail_dirty; - - avail_dirty = global_page_state(NR_FILE_DIRTY) + - global_page_state(NR_WRITEBACK) + - global_page_state(NR_UNSTABLE_NFS) + - global_page_state(NR_WRITEBACK_TEMP); - - if (avail_dirty < dirty) - avail_dirty = dirty - avail_dirty; - else - avail_dirty = 0; - - avail_dirty += bdi_stat(bdi, BDI_RECLAIMABLE) + - bdi_stat(bdi, BDI_WRITEBACK); - - *pbdi_dirty = min(*pbdi_dirty, avail_dirty); -} - static inline void task_dirties_fraction(struct task_struct *tsk, long *numerator, long *denominator) { @@ -286,16 +261,24 @@ static inline void task_dirties_fraction(struct task_struct *tsk, } /* - * scale the dirty limit + * task_dirty_limit - scale down dirty throttling threshold for one task * * task specific dirty limit: * * dirty -= (dirty/8) * p_{t} + * + * To protect light/slow dirtying tasks from heavier/fast ones, we start + * throttling individual tasks before reaching the bdi dirty limit. + * Relatively low thresholds will be allocated to heavy dirtiers. So when + * dirty pages grow large, heavy dirtiers will be throttled first, which will + * effectively curb the growth of dirty pages. Light dirtiers with high enough + * dirty threshold may never get throttled. */ -static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty) +static unsigned long task_dirty_limit(struct task_struct *tsk, + unsigned long bdi_dirty) { long numerator, denominator; - unsigned long dirty = *pdirty; + unsigned long dirty = bdi_dirty; u64 inv = dirty >> 3; task_dirties_fraction(tsk, &numerator, &denominator); @@ -303,10 +286,8 @@ static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty) do_div(inv, denominator); dirty -= inv; - if (dirty < *pdirty/2) - dirty = *pdirty/2; - *pdirty = dirty; + return max(dirty, bdi_dirty/2); } /* @@ -416,9 +397,16 @@ unsigned long determine_dirtyable_memory(void) return x + 1; /* Ensure that we never return 0 */ } -void -get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty, - unsigned long *pbdi_dirty, struct backing_dev_info *bdi) +/** + * global_dirty_limits - background-writeback and dirty-throttling thresholds + * + * Calculate the dirty thresholds based on sysctl parameters + * - vm.dirty_background_ratio or vm.dirty_background_bytes + * - vm.dirty_ratio or vm.dirty_bytes + * The dirty limits will be lifted by 1/4 for PF_LESS_THROTTLE (ie. nfsd) and + * runtime tasks. + */ +void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty) { unsigned long background; unsigned long dirty; @@ -450,27 +438,37 @@ get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty, } *pbackground = background; *pdirty = dirty; +} - if (bdi) { - u64 bdi_dirty; - long numerator, denominator; +/** + * bdi_dirty_limit - @bdi's share of dirty throttling threshold + * + * Allocate high/low dirty limits to fast/slow devices, in order to prevent + * - starving fast devices + * - piling up dirty pages (that will take long time to sync) on slow devices + * + * The bdi's share of dirty limit will be adapting to its throughput and + * bounded by the bdi->min_ratio and/or bdi->max_ratio parameters, if set. + */ +unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long dirty) +{ + u64 bdi_dirty; + long numerator, denominator; - /* - * Calculate this BDI's share of the dirty ratio. - */ - bdi_writeout_fraction(bdi, &numerator, &denominator); - - bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100; - bdi_dirty *= numerator; - do_div(bdi_dirty, denominator); - bdi_dirty += (dirty * bdi->min_ratio) / 100; - if (bdi_dirty > (dirty * bdi->max_ratio) / 100) - bdi_dirty = dirty * bdi->max_ratio / 100; - - *pbdi_dirty = bdi_dirty; - clip_bdi_dirty_limit(bdi, dirty, pbdi_dirty); - task_dirty_limit(current, pbdi_dirty); - } + /* + * Calculate this BDI's share of the dirty ratio. + */ + bdi_writeout_fraction(bdi, &numerator, &denominator); + + bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100; + bdi_dirty *= numerator; + do_div(bdi_dirty, denominator); + + bdi_dirty += (dirty * bdi->min_ratio) / 100; + if (bdi_dirty > (dirty * bdi->max_ratio) / 100) + bdi_dirty = dirty * bdi->max_ratio / 100; + + return bdi_dirty; } /* @@ -490,7 +488,7 @@ static void balance_dirty_pages(struct address_space *mapping, unsigned long bdi_thresh; unsigned long pages_written = 0; unsigned long pause = 1; - + bool dirty_exceeded = false; struct backing_dev_info *bdi = mapping->backing_dev_info; for (;;) { @@ -501,18 +499,11 @@ static void balance_dirty_pages(struct address_space *mapping, .range_cyclic = 1, }; - get_dirty_limits(&background_thresh, &dirty_thresh, - &bdi_thresh, bdi); - nr_reclaimable = global_page_state(NR_FILE_DIRTY) + global_page_state(NR_UNSTABLE_NFS); nr_writeback = global_page_state(NR_WRITEBACK); - bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE); - bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK); - - if (bdi_nr_reclaimable + bdi_nr_writeback <= bdi_thresh) - break; + global_dirty_limits(&background_thresh, &dirty_thresh); /* * Throttle it only when the background writeback cannot @@ -523,24 +514,8 @@ static void balance_dirty_pages(struct address_space *mapping, (background_thresh + dirty_thresh) / 2) break; - if (!bdi->dirty_exceeded) - bdi->dirty_exceeded = 1; - - /* Note: nr_reclaimable denotes nr_dirty + nr_unstable. - * Unstable writes are a feature of certain networked - * filesystems (i.e. NFS) in which data may have been - * written to the server's write cache, but has not yet - * been flushed to permanent storage. - * Only move pages to writeback if this bdi is over its - * threshold otherwise wait until the disk writes catch - * up. - */ - if (bdi_nr_reclaimable > bdi_thresh) { - writeback_inodes_wb(&bdi->wb, &wbc); - pages_written += write_chunk - wbc.nr_to_write; - get_dirty_limits(&background_thresh, &dirty_thresh, - &bdi_thresh, bdi); - } + bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh); + bdi_thresh = task_dirty_limit(current, bdi_thresh); /* * In order to avoid the stacked BDI deadlock we need @@ -555,16 +530,45 @@ static void balance_dirty_pages(struct address_space *mapping, if (bdi_thresh < 2*bdi_stat_error(bdi)) { bdi_nr_reclaimable = bdi_stat_sum(bdi, BDI_RECLAIMABLE); bdi_nr_writeback = bdi_stat_sum(bdi, BDI_WRITEBACK); - } else if (bdi_nr_reclaimable) { + } else { bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE); bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK); } - if (bdi_nr_reclaimable + bdi_nr_writeback <= bdi_thresh) + /* + * The bdi thresh is somehow "soft" limit derived from the + * global "hard" limit. The former helps to prevent heavy IO + * bdi or process from holding back light ones; The latter is + * the last resort safeguard. + */ + dirty_exceeded = + (bdi_nr_reclaimable + bdi_nr_writeback >= bdi_thresh) + || (nr_reclaimable + nr_writeback >= dirty_thresh); + + if (!dirty_exceeded) break; - if (pages_written >= write_chunk) - break; /* We've done our duty */ + if (!bdi->dirty_exceeded) + bdi->dirty_exceeded = 1; + + /* Note: nr_reclaimable denotes nr_dirty + nr_unstable. + * Unstable writes are a feature of certain networked + * filesystems (i.e. NFS) in which data may have been + * written to the server's write cache, but has not yet + * been flushed to permanent storage. + * Only move pages to writeback if this bdi is over its + * threshold otherwise wait until the disk writes catch + * up. + */ + trace_wbc_balance_dirty_start(&wbc, bdi); + if (bdi_nr_reclaimable > bdi_thresh) { + writeback_inodes_wb(&bdi->wb, &wbc); + pages_written += write_chunk - wbc.nr_to_write; + trace_wbc_balance_dirty_written(&wbc, bdi); + if (pages_written >= write_chunk) + break; /* We've done our duty */ + } + trace_wbc_balance_dirty_wait(&wbc, bdi); __set_current_state(TASK_INTERRUPTIBLE); io_schedule_timeout(pause); @@ -577,8 +581,7 @@ static void balance_dirty_pages(struct address_space *mapping, pause = HZ / 10; } - if (bdi_nr_reclaimable + bdi_nr_writeback < bdi_thresh && - bdi->dirty_exceeded) + if (!dirty_exceeded && bdi->dirty_exceeded) bdi->dirty_exceeded = 0; if (writeback_in_progress(bdi)) @@ -593,9 +596,7 @@ static void balance_dirty_pages(struct address_space *mapping, * background_thresh, to keep the amount of dirty memory low. */ if ((laptop_mode && pages_written) || - (!laptop_mode && ((global_page_state(NR_FILE_DIRTY) - + global_page_state(NR_UNSTABLE_NFS)) - > background_thresh))) + (!laptop_mode && (nr_reclaimable > background_thresh))) bdi_start_background_writeback(bdi); } @@ -659,7 +660,7 @@ void throttle_vm_writeout(gfp_t gfp_mask) unsigned long dirty_thresh; for ( ; ; ) { - get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL); + global_dirty_limits(&background_thresh, &dirty_thresh); /* * Boost the allowable dirty threshold a bit for page @@ -805,6 +806,41 @@ void __init page_writeback_init(void) } /** + * tag_pages_for_writeback - tag pages to be written by write_cache_pages + * @mapping: address space structure to write + * @start: starting page index + * @end: ending page index (inclusive) + * + * This function scans the page range from @start to @end (inclusive) and tags + * all pages that have DIRTY tag set with a special TOWRITE tag. The idea is + * that write_cache_pages (or whoever calls this function) will then use + * TOWRITE tag to identify pages eligible for writeback. This mechanism is + * used to avoid livelocking of writeback by a process steadily creating new + * dirty pages in the file (thus it is important for this function to be quick + * so that it can tag pages faster than a dirtying process can create them). + */ +/* + * We tag pages in batches of WRITEBACK_TAG_BATCH to reduce tree_lock latency. + */ +void tag_pages_for_writeback(struct address_space *mapping, + pgoff_t start, pgoff_t end) +{ +#define WRITEBACK_TAG_BATCH 4096 + unsigned long tagged; + + do { + spin_lock_irq(&mapping->tree_lock); + tagged = radix_tree_range_tag_if_tagged(&mapping->page_tree, + &start, end, WRITEBACK_TAG_BATCH, + PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE); + spin_unlock_irq(&mapping->tree_lock); + WARN_ON_ONCE(tagged > WRITEBACK_TAG_BATCH); + cond_resched(); + } while (tagged >= WRITEBACK_TAG_BATCH); +} +EXPORT_SYMBOL(tag_pages_for_writeback); + +/** * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. * @mapping: address space structure to write * @wbc: subtract the number of written pages from *@wbc->nr_to_write @@ -818,6 +854,13 @@ void __init page_writeback_init(void) * the call was made get new I/O started against them. If wbc->sync_mode is * WB_SYNC_ALL then we were called for data integrity and we must wait for * existing IO to complete. + * + * To avoid livelocks (when other process dirties new pages), we first tag + * pages which should be written back with TOWRITE tag and only then start + * writing them. For data-integrity sync we have to be careful so that we do + * not miss some pages (e.g., because some other process has cleared TOWRITE + * tag we set). The rule we follow is that TOWRITE tag can be cleared only + * by the process clearing the DIRTY tag (and submitting the page for IO). */ int write_cache_pages(struct address_space *mapping, struct writeback_control *wbc, writepage_t writepage, @@ -833,6 +876,7 @@ int write_cache_pages(struct address_space *mapping, pgoff_t done_index; int cycled; int range_whole = 0; + int tag; pagevec_init(&pvec, 0); if (wbc->range_cyclic) { @@ -849,29 +893,19 @@ int write_cache_pages(struct address_space *mapping, if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) range_whole = 1; cycled = 1; /* ignore range_cyclic tests */ - - /* - * If this is a data integrity sync, cap the writeback to the - * current end of file. Any extension to the file that occurs - * after this is a new write and we don't need to write those - * pages out to fulfil our data integrity requirements. If we - * try to write them out, we can get stuck in this scan until - * the concurrent writer stops adding dirty pages and extending - * EOF. - */ - if (wbc->sync_mode == WB_SYNC_ALL && - wbc->range_end == LLONG_MAX) { - end = i_size_read(mapping->host) >> PAGE_CACHE_SHIFT; - } } - + if (wbc->sync_mode == WB_SYNC_ALL) + tag = PAGECACHE_TAG_TOWRITE; + else + tag = PAGECACHE_TAG_DIRTY; retry: + if (wbc->sync_mode == WB_SYNC_ALL) + tag_pages_for_writeback(mapping, index, end); done_index = index; while (!done && (index <= end)) { int i; - nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, - PAGECACHE_TAG_DIRTY, + nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag, min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1); if (nr_pages == 0) break; @@ -929,6 +963,7 @@ continue_unlock: if (!clear_page_dirty_for_io(page)) goto continue_unlock; + trace_wbc_writepage(wbc, mapping->backing_dev_info); ret = (*writepage)(page, wbc, data); if (unlikely(ret)) { if (ret == AOP_WRITEPAGE_ACTIVATE) { @@ -1327,6 +1362,9 @@ int test_set_page_writeback(struct page *page) radix_tree_tag_clear(&mapping->page_tree, page_index(page), PAGECACHE_TAG_DIRTY); + radix_tree_tag_clear(&mapping->page_tree, + page_index(page), + PAGECACHE_TAG_TOWRITE); spin_unlock_irqrestore(&mapping->tree_lock, flags); } else { ret = TestSetPageWriteback(page); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9bd339eb04c..a9649f4b261 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1738,7 +1738,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, struct page *page; /* Acquire the OOM killer lock for the zones in zonelist */ - if (!try_set_zone_oom(zonelist, gfp_mask)) { + if (!try_set_zonelist_oom(zonelist, gfp_mask)) { schedule_timeout_uninterruptible(1); return NULL; } @@ -1759,6 +1759,9 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, /* The OOM killer will not help higher order allocs */ if (order > PAGE_ALLOC_COSTLY_ORDER) goto out; + /* The OOM killer does not needlessly kill tasks for lowmem */ + if (high_zoneidx < ZONE_NORMAL) + goto out; /* * GFP_THISNODE contains __GFP_NORETRY and we never hit this. * Sanity check for bare calls of __GFP_THISNODE, not real OOM. @@ -2052,15 +2055,23 @@ rebalance: if (page) goto got_pg; - /* - * The OOM killer does not trigger for high-order - * ~__GFP_NOFAIL allocations so if no progress is being - * made, there are no other options and retrying is - * unlikely to help. - */ - if (order > PAGE_ALLOC_COSTLY_ORDER && - !(gfp_mask & __GFP_NOFAIL)) - goto nopage; + if (!(gfp_mask & __GFP_NOFAIL)) { + /* + * The oom killer is not called for high-order + * allocations that may fail, so if no progress + * is being made, there are no other options and + * retrying is unlikely to help. + */ + if (order > PAGE_ALLOC_COSTLY_ORDER) + goto nopage; + /* + * The oom killer is not called for lowmem + * allocations to prevent needlessly killing + * innocent tasks. + */ + if (high_zoneidx < ZONE_NORMAL) + goto nopage; + } goto restart; } @@ -4089,8 +4100,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, zone_seqlock_init(zone); zone->zone_pgdat = pgdat; - zone->prev_priority = DEF_PRIORITY; - zone_pcp_init(zone); for_each_lru(l) { INIT_LIST_HEAD(&zone->lru[l].list); diff --git a/mm/page_io.c b/mm/page_io.c index 31a3b962230..2dee975bf46 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -106,7 +106,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc) goto out; } if (wbc->sync_mode == WB_SYNC_ALL) - rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); + rw |= REQ_SYNC | REQ_UNPLUG; count_vm_event(PSWPOUT); set_page_writeback(page); unlock_page(page); diff --git a/mm/rmap.c b/mm/rmap.c index 38a336e2eea..87b9e8ad450 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -56,6 +56,7 @@ #include <linux/memcontrol.h> #include <linux/mmu_notifier.h> #include <linux/migrate.h> +#include <linux/hugetlb.h> #include <asm/tlbflush.h> @@ -132,9 +133,14 @@ int anon_vma_prepare(struct vm_area_struct *vma) if (unlikely(!anon_vma)) goto out_enomem_free_avc; allocated = anon_vma; + /* + * This VMA had no anon_vma yet. This anon_vma is + * the root of any anon_vma tree that might form. + */ + anon_vma->root = anon_vma; } - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); /* page_table_lock to protect against threads */ spin_lock(&mm->page_table_lock); if (likely(!vma->anon_vma)) { @@ -142,12 +148,12 @@ int anon_vma_prepare(struct vm_area_struct *vma) avc->anon_vma = anon_vma; avc->vma = vma; list_add(&avc->same_vma, &vma->anon_vma_chain); - list_add(&avc->same_anon_vma, &anon_vma->head); + list_add_tail(&avc->same_anon_vma, &anon_vma->head); allocated = NULL; avc = NULL; } spin_unlock(&mm->page_table_lock); - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); if (unlikely(allocated)) anon_vma_free(allocated); @@ -170,9 +176,9 @@ static void anon_vma_chain_link(struct vm_area_struct *vma, avc->anon_vma = anon_vma; list_add(&avc->same_vma, &vma->anon_vma_chain); - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_add_tail(&avc->same_anon_vma, &anon_vma->head); - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); } /* @@ -224,9 +230,21 @@ int anon_vma_fork(struct vm_area_struct *vma, struct vm_area_struct *pvma) avc = anon_vma_chain_alloc(); if (!avc) goto out_error_free_anon_vma; - anon_vma_chain_link(vma, avc, anon_vma); + + /* + * The root anon_vma's spinlock is the lock actually used when we + * lock any of the anon_vmas in this anon_vma tree. + */ + anon_vma->root = pvma->anon_vma->root; + /* + * With KSM refcounts, an anon_vma can stay around longer than the + * process it belongs to. The root anon_vma needs to be pinned + * until this anon_vma is freed, because the lock lives in the root. + */ + get_anon_vma(anon_vma->root); /* Mark this anon_vma as the one where our new (COWed) pages go. */ vma->anon_vma = anon_vma; + anon_vma_chain_link(vma, avc, anon_vma); return 0; @@ -246,22 +264,29 @@ static void anon_vma_unlink(struct anon_vma_chain *anon_vma_chain) if (!anon_vma) return; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_del(&anon_vma_chain->same_anon_vma); /* We must garbage collect the anon_vma if it's empty */ empty = list_empty(&anon_vma->head) && !anonvma_external_refcount(anon_vma); - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); - if (empty) + if (empty) { + /* We no longer need the root anon_vma */ + if (anon_vma->root != anon_vma) + drop_anon_vma(anon_vma->root); anon_vma_free(anon_vma); + } } void unlink_anon_vmas(struct vm_area_struct *vma) { struct anon_vma_chain *avc, *next; - /* Unlink each anon_vma chained to the VMA. */ + /* + * Unlink each anon_vma chained to the VMA. This list is ordered + * from newest to oldest, ensuring the root anon_vma gets freed last. + */ list_for_each_entry_safe(avc, next, &vma->anon_vma_chain, same_vma) { anon_vma_unlink(avc); list_del(&avc->same_vma); @@ -302,7 +327,7 @@ struct anon_vma *page_lock_anon_vma(struct page *page) goto out; anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON); - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); return anon_vma; out: rcu_read_unlock(); @@ -311,7 +336,7 @@ out: void page_unlock_anon_vma(struct anon_vma *anon_vma) { - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); rcu_read_unlock(); } @@ -326,6 +351,8 @@ vma_address(struct page *page, struct vm_area_struct *vma) pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); unsigned long address; + if (unlikely(is_vm_hugetlb_page(vma))) + pgoff = page->index << huge_page_order(page_hstate(page)); address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); if (unlikely(address < vma->vm_start || address >= vma->vm_end)) { /* page should be within @vma mapping range */ @@ -340,9 +367,10 @@ vma_address(struct page *page, struct vm_area_struct *vma) */ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma) { - if (PageAnon(page)) - ; - else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) { + if (PageAnon(page)) { + if (vma->anon_vma->root != page_anon_vma(page)->root) + return -EFAULT; + } else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) { if (!vma->vm_file || vma->vm_file->f_mapping != page->mapping) return -EFAULT; @@ -369,6 +397,12 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm, pte_t *pte; spinlock_t *ptl; + if (unlikely(PageHuge(page))) { + pte = huge_pte_offset(mm, address); + ptl = &mm->page_table_lock; + goto check; + } + pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) return NULL; @@ -389,6 +423,7 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm, } ptl = pte_lockptr(mm, pmd); +check: spin_lock(ptl); if (pte_present(*pte) && page_to_pfn(page) == pte_pfn(*pte)) { *ptlp = ptl; @@ -743,14 +778,20 @@ static void __page_set_anon_rmap(struct page *page, * If the page isn't exclusively mapped into this vma, * we must use the _oldest_ possible anon_vma for the * page mapping! - * - * So take the last AVC chain entry in the vma, which is - * the deepest ancestor, and use the anon_vma from that. */ if (!exclusive) { - struct anon_vma_chain *avc; - avc = list_entry(vma->anon_vma_chain.prev, struct anon_vma_chain, same_vma); - anon_vma = avc->anon_vma; + if (PageAnon(page)) + return; + anon_vma = anon_vma->root; + } else { + /* + * In this case, swapped-out-but-not-discarded swap-cache + * is remapped. So, no need to update page->mapping here. + * We convice anon_vma poitned by page->mapping is not obsolete + * because vma->anon_vma is necessary to be a family of it. + */ + if (PageAnon(page)) + return; } anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; @@ -780,6 +821,7 @@ static void __page_check_anon_rmap(struct page *page, * are initially only visible via the pagetables, and the pte is locked * over the call to page_add_new_anon_rmap. */ + BUG_ON(page_anon_vma(page)->root != vma->anon_vma->root); BUG_ON(page->index != linear_page_index(vma, address)); #endif } @@ -798,6 +840,17 @@ static void __page_check_anon_rmap(struct page *page, void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address) { + do_page_add_anon_rmap(page, vma, address, 0); +} + +/* + * Special version of the above for do_swap_page, which often runs + * into pages that are exclusively owned by the current process. + * Everybody else should continue to use page_add_anon_rmap above. + */ +void do_page_add_anon_rmap(struct page *page, + struct vm_area_struct *vma, unsigned long address, int exclusive) +{ int first = atomic_inc_and_test(&page->_mapcount); if (first) __inc_zone_page_state(page, NR_ANON_PAGES); @@ -807,7 +860,7 @@ void page_add_anon_rmap(struct page *page, VM_BUG_ON(!PageLocked(page)); VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end); if (first) - __page_set_anon_rmap(page, vma, address, 0); + __page_set_anon_rmap(page, vma, address, exclusive); else __page_check_anon_rmap(page, vma, address); } @@ -873,6 +926,12 @@ void page_remove_rmap(struct page *page) page_clear_dirty(page); set_page_dirty(page); } + /* + * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED + * and not charged by memcg for now. + */ + if (unlikely(PageHuge(page))) + return; if (PageAnon(page)) { mem_cgroup_uncharge_page(page); __dec_zone_page_state(page, NR_ANON_PAGES); @@ -1368,6 +1427,42 @@ int try_to_munlock(struct page *page) return try_to_unmap_file(page, TTU_MUNLOCK); } +#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION) +/* + * Drop an anon_vma refcount, freeing the anon_vma and anon_vma->root + * if necessary. Be careful to do all the tests under the lock. Once + * we know we are the last user, nobody else can get a reference and we + * can do the freeing without the lock. + */ +void drop_anon_vma(struct anon_vma *anon_vma) +{ + BUG_ON(atomic_read(&anon_vma->external_refcount) <= 0); + if (atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->root->lock)) { + struct anon_vma *root = anon_vma->root; + int empty = list_empty(&anon_vma->head); + int last_root_user = 0; + int root_empty = 0; + + /* + * The refcount on a non-root anon_vma got dropped. Drop + * the refcount on the root and check if we need to free it. + */ + if (empty && anon_vma != root) { + BUG_ON(atomic_read(&root->external_refcount) <= 0); + last_root_user = atomic_dec_and_test(&root->external_refcount); + root_empty = list_empty(&root->head); + } + anon_vma_unlock(anon_vma); + + if (empty) { + anon_vma_free(anon_vma); + if (root_empty && last_root_user) + anon_vma_free(root); + } + } +} +#endif + #ifdef CONFIG_MIGRATION /* * rmap_walk() and its helpers rmap_walk_anon() and rmap_walk_file(): @@ -1389,7 +1484,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, anon_vma = page_anon_vma(page); if (!anon_vma) return ret; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { struct vm_area_struct *vma = avc->vma; unsigned long address = vma_address(page, vma); @@ -1399,7 +1494,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, if (ret != SWAP_AGAIN) break; } - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); return ret; } @@ -1445,3 +1540,46 @@ int rmap_walk(struct page *page, int (*rmap_one)(struct page *, return rmap_walk_file(page, rmap_one, arg); } #endif /* CONFIG_MIGRATION */ + +#ifdef CONFIG_HUGETLB_PAGE +/* + * The following three functions are for anonymous (private mapped) hugepages. + * Unlike common anonymous pages, anonymous hugepages have no accounting code + * and no lru code, because we handle hugepages differently from common pages. + */ +static void __hugepage_set_anon_rmap(struct page *page, + struct vm_area_struct *vma, unsigned long address, int exclusive) +{ + struct anon_vma *anon_vma = vma->anon_vma; + BUG_ON(!anon_vma); + if (!exclusive) { + struct anon_vma_chain *avc; + avc = list_entry(vma->anon_vma_chain.prev, + struct anon_vma_chain, same_vma); + anon_vma = avc->anon_vma; + } + anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; + page->mapping = (struct address_space *) anon_vma; + page->index = linear_page_index(vma, address); +} + +void hugepage_add_anon_rmap(struct page *page, + struct vm_area_struct *vma, unsigned long address) +{ + struct anon_vma *anon_vma = vma->anon_vma; + int first; + BUG_ON(!anon_vma); + BUG_ON(address < vma->vm_start || address >= vma->vm_end); + first = atomic_inc_and_test(&page->_mapcount); + if (first) + __hugepage_set_anon_rmap(page, vma, address, 0); +} + +void hugepage_add_new_anon_rmap(struct page *page, + struct vm_area_struct *vma, unsigned long address) +{ + BUG_ON(address < vma->vm_start || address >= vma->vm_end); + atomic_set(&page->_mapcount, 0); + __hugepage_set_anon_rmap(page, vma, address, 1); +} +#endif /* CONFIG_HUGETLB_PAGE */ diff --git a/mm/shmem.c b/mm/shmem.c index f65f84062db..dfaa0f4e978 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -28,6 +28,7 @@ #include <linux/file.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/percpu_counter.h> #include <linux/swap.h> static struct vfsmount *shm_mnt; @@ -233,10 +234,10 @@ static void shmem_free_blocks(struct inode *inode, long pages) { struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); if (sbinfo->max_blocks) { - spin_lock(&sbinfo->stat_lock); - sbinfo->free_blocks += pages; + percpu_counter_add(&sbinfo->used_blocks, -pages); + spin_lock(&inode->i_lock); inode->i_blocks -= pages*BLOCKS_PER_PAGE; - spin_unlock(&sbinfo->stat_lock); + spin_unlock(&inode->i_lock); } } @@ -416,19 +417,17 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long if (sgp == SGP_READ) return shmem_swp_map(ZERO_PAGE(0)); /* - * Test free_blocks against 1 not 0, since we have 1 data + * Test used_blocks against 1 less max_blocks, since we have 1 data * page (and perhaps indirect index pages) yet to allocate: * a waste to allocate index if we cannot allocate data. */ if (sbinfo->max_blocks) { - spin_lock(&sbinfo->stat_lock); - if (sbinfo->free_blocks <= 1) { - spin_unlock(&sbinfo->stat_lock); + if (percpu_counter_compare(&sbinfo->used_blocks, (sbinfo->max_blocks - 1)) > 0) return ERR_PTR(-ENOSPC); - } - sbinfo->free_blocks--; + percpu_counter_inc(&sbinfo->used_blocks); + spin_lock(&inode->i_lock); inode->i_blocks += BLOCKS_PER_PAGE; - spin_unlock(&sbinfo->stat_lock); + spin_unlock(&inode->i_lock); } spin_unlock(&info->lock); @@ -767,6 +766,10 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr) loff_t newsize = attr->ia_size; int error; + error = inode_change_ok(inode, attr); + if (error) + return error; + if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE) && newsize != inode->i_size) { struct page *page = NULL; @@ -801,25 +804,22 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr) } } - error = simple_setsize(inode, newsize); + /* XXX(truncate): truncate_setsize should be called last */ + truncate_setsize(inode, newsize); if (page) page_cache_release(page); - if (error) - return error; shmem_truncate_range(inode, newsize, (loff_t)-1); } - error = inode_change_ok(inode, attr); - if (!error) - generic_setattr(inode, attr); + setattr_copy(inode, attr); #ifdef CONFIG_TMPFS_POSIX_ACL - if (!error && (attr->ia_valid & ATTR_MODE)) + if (attr->ia_valid & ATTR_MODE) error = generic_acl_chmod(inode); #endif return error; } -static void shmem_delete_inode(struct inode *inode) +static void shmem_evict_inode(struct inode *inode) { struct shmem_inode_info *info = SHMEM_I(inode); @@ -836,7 +836,7 @@ static void shmem_delete_inode(struct inode *inode) } BUG_ON(inode->i_blocks); shmem_free_inode(inode->i_sb); - clear_inode(inode); + end_writeback(inode); } static inline int shmem_find_swp(swp_entry_t entry, swp_entry_t *dir, swp_entry_t *edir) @@ -933,7 +933,7 @@ found: /* * Move _head_ to start search for next from here. - * But be careful: shmem_delete_inode checks list_empty without taking + * But be careful: shmem_evict_inode checks list_empty without taking * mutex, and there's an instant in list_move_tail when info->swaplist * would appear empty, if it were the only one on shmem_swaplist. We * could avoid doing it if inode NULL; or use this minor optimization. @@ -1223,6 +1223,7 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct shmem_sb_info *sbinfo; struct page *filepage = *pagep; struct page *swappage; + struct page *prealloc_page = NULL; swp_entry_t *entry; swp_entry_t swap; gfp_t gfp; @@ -1247,7 +1248,6 @@ repeat: filepage = find_lock_page(mapping, idx); if (filepage && PageUptodate(filepage)) goto done; - error = 0; gfp = mapping_gfp_mask(mapping); if (!filepage) { /* @@ -1258,7 +1258,19 @@ repeat: if (error) goto failed; radix_tree_preload_end(); + if (sgp != SGP_READ && !prealloc_page) { + /* We don't care if this fails */ + prealloc_page = shmem_alloc_page(gfp, info, idx); + if (prealloc_page) { + if (mem_cgroup_cache_charge(prealloc_page, + current->mm, GFP_KERNEL)) { + page_cache_release(prealloc_page); + prealloc_page = NULL; + } + } + } } + error = 0; spin_lock(&info->lock); shmem_recalc_inode(inode); @@ -1387,17 +1399,16 @@ repeat: shmem_swp_unmap(entry); sbinfo = SHMEM_SB(inode->i_sb); if (sbinfo->max_blocks) { - spin_lock(&sbinfo->stat_lock); - if (sbinfo->free_blocks == 0 || + if ((percpu_counter_compare(&sbinfo->used_blocks, sbinfo->max_blocks) > 0) || shmem_acct_block(info->flags)) { - spin_unlock(&sbinfo->stat_lock); spin_unlock(&info->lock); error = -ENOSPC; goto failed; } - sbinfo->free_blocks--; + percpu_counter_inc(&sbinfo->used_blocks); + spin_lock(&inode->i_lock); inode->i_blocks += BLOCKS_PER_PAGE; - spin_unlock(&sbinfo->stat_lock); + spin_unlock(&inode->i_lock); } else if (shmem_acct_block(info->flags)) { spin_unlock(&info->lock); error = -ENOSPC; @@ -1407,28 +1418,38 @@ repeat: if (!filepage) { int ret; - spin_unlock(&info->lock); - filepage = shmem_alloc_page(gfp, info, idx); - if (!filepage) { - shmem_unacct_blocks(info->flags, 1); - shmem_free_blocks(inode, 1); - error = -ENOMEM; - goto failed; - } - SetPageSwapBacked(filepage); + if (!prealloc_page) { + spin_unlock(&info->lock); + filepage = shmem_alloc_page(gfp, info, idx); + if (!filepage) { + shmem_unacct_blocks(info->flags, 1); + shmem_free_blocks(inode, 1); + error = -ENOMEM; + goto failed; + } + SetPageSwapBacked(filepage); - /* Precharge page while we can wait, compensate after */ - error = mem_cgroup_cache_charge(filepage, current->mm, - GFP_KERNEL); - if (error) { - page_cache_release(filepage); - shmem_unacct_blocks(info->flags, 1); - shmem_free_blocks(inode, 1); - filepage = NULL; - goto failed; + /* + * Precharge page while we can wait, compensate + * after + */ + error = mem_cgroup_cache_charge(filepage, + current->mm, GFP_KERNEL); + if (error) { + page_cache_release(filepage); + shmem_unacct_blocks(info->flags, 1); + shmem_free_blocks(inode, 1); + filepage = NULL; + goto failed; + } + + spin_lock(&info->lock); + } else { + filepage = prealloc_page; + prealloc_page = NULL; + SetPageSwapBacked(filepage); } - spin_lock(&info->lock); entry = shmem_swp_alloc(info, idx, sgp); if (IS_ERR(entry)) error = PTR_ERR(entry); @@ -1469,13 +1490,19 @@ repeat: } done: *pagep = filepage; - return 0; + error = 0; + goto out; failed: if (*pagep != filepage) { unlock_page(filepage); page_cache_release(filepage); } +out: + if (prealloc_page) { + mem_cgroup_uncharge_cache_page(prealloc_page); + page_cache_release(prealloc_page); + } return error; } @@ -1791,17 +1818,16 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_type = TMPFS_MAGIC; buf->f_bsize = PAGE_CACHE_SIZE; buf->f_namelen = NAME_MAX; - spin_lock(&sbinfo->stat_lock); if (sbinfo->max_blocks) { buf->f_blocks = sbinfo->max_blocks; - buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; + buf->f_bavail = buf->f_bfree = + sbinfo->max_blocks - percpu_counter_sum(&sbinfo->used_blocks); } if (sbinfo->max_inodes) { buf->f_files = sbinfo->max_inodes; buf->f_ffree = sbinfo->free_inodes; } /* else leave those fields 0 like simple_statfs */ - spin_unlock(&sbinfo->stat_lock); return 0; } @@ -2242,7 +2268,6 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) { struct shmem_sb_info *sbinfo = SHMEM_SB(sb); struct shmem_sb_info config = *sbinfo; - unsigned long blocks; unsigned long inodes; int error = -EINVAL; @@ -2250,9 +2275,8 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) return error; spin_lock(&sbinfo->stat_lock); - blocks = sbinfo->max_blocks - sbinfo->free_blocks; inodes = sbinfo->max_inodes - sbinfo->free_inodes; - if (config.max_blocks < blocks) + if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0) goto out; if (config.max_inodes < inodes) goto out; @@ -2269,7 +2293,6 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) error = 0; sbinfo->max_blocks = config.max_blocks; - sbinfo->free_blocks = config.max_blocks - blocks; sbinfo->max_inodes = config.max_inodes; sbinfo->free_inodes = config.max_inodes - inodes; @@ -2344,7 +2367,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent) #endif spin_lock_init(&sbinfo->stat_lock); - sbinfo->free_blocks = sbinfo->max_blocks; + percpu_counter_init(&sbinfo->used_blocks, 0); sbinfo->free_inodes = sbinfo->max_inodes; sb->s_maxbytes = SHMEM_MAX_BYTES; @@ -2496,7 +2519,7 @@ static const struct super_operations shmem_ops = { .remount_fs = shmem_remount_fs, .show_options = shmem_show_options, #endif - .delete_inode = shmem_delete_inode, + .evict_inode = shmem_evict_inode, .drop_inode = generic_delete_inode, .put_super = shmem_put_super, }; diff --git a/mm/slab.c b/mm/slab.c index 736e497733d..88435fcc838 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -394,7 +394,7 @@ static void kmem_list3_init(struct kmem_list3 *parent) #define STATS_DEC_ACTIVE(x) do { } while (0) #define STATS_INC_ALLOCED(x) do { } while (0) #define STATS_INC_GROWN(x) do { } while (0) -#define STATS_ADD_REAPED(x,y) do { } while (0) +#define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) #define STATS_SET_HIGH(x) do { } while (0) #define STATS_INC_ERR(x) do { } while (0) #define STATS_INC_NODEALLOCS(x) do { } while (0) diff --git a/mm/swapfile.c b/mm/swapfile.c index 03aa2d55f1a..1f3f9c59a73 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -47,6 +47,8 @@ long nr_swap_pages; long total_swap_pages; static int least_priority; +static bool swap_for_hibernation; + static const char Bad_file[] = "Bad swap file entry "; static const char Unused_file[] = "Unused swap file entry "; static const char Bad_offset[] = "Bad swap offset entry "; @@ -318,8 +320,10 @@ checks: if (offset > si->highest_bit) scan_base = offset = si->lowest_bit; - /* reuse swap entry of cache-only swap if not busy. */ - if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { + /* reuse swap entry of cache-only swap if not hibernation. */ + if (vm_swap_full() + && usage == SWAP_HAS_CACHE + && si->swap_map[offset] == SWAP_HAS_CACHE) { int swap_was_freed; spin_unlock(&swap_lock); swap_was_freed = __try_to_reclaim_swap(si, offset); @@ -449,6 +453,8 @@ swp_entry_t get_swap_page(void) spin_lock(&swap_lock); if (nr_swap_pages <= 0) goto noswap; + if (swap_for_hibernation) + goto noswap; nr_swap_pages--; for (type = swap_list.next; type >= 0 && wrapped < 2; type = next) { @@ -481,28 +487,6 @@ noswap: return (swp_entry_t) {0}; } -/* The only caller of this function is now susupend routine */ -swp_entry_t get_swap_page_of_type(int type) -{ - struct swap_info_struct *si; - pgoff_t offset; - - spin_lock(&swap_lock); - si = swap_info[type]; - if (si && (si->flags & SWP_WRITEOK)) { - nr_swap_pages--; - /* This is called for allocating swap entry, not cache */ - offset = scan_swap_map(si, 1); - if (offset) { - spin_unlock(&swap_lock); - return swp_entry(type, offset); - } - nr_swap_pages++; - } - spin_unlock(&swap_lock); - return (swp_entry_t) {0}; -} - static struct swap_info_struct *swap_info_get(swp_entry_t entry) { struct swap_info_struct *p; @@ -762,6 +746,74 @@ int mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep) #endif #ifdef CONFIG_HIBERNATION + +static pgoff_t hibernation_offset[MAX_SWAPFILES]; +/* + * Once hibernation starts to use swap, we freeze swap_map[]. Otherwise, + * saved swap_map[] image to the disk will be an incomplete because it's + * changing without synchronization with hibernation snap shot. + * At resume, we just make swap_for_hibernation=false. We can forget + * used maps easily. + */ +void hibernation_freeze_swap(void) +{ + int i; + + spin_lock(&swap_lock); + + printk(KERN_INFO "PM: Freeze Swap\n"); + swap_for_hibernation = true; + for (i = 0; i < MAX_SWAPFILES; i++) + hibernation_offset[i] = 1; + spin_unlock(&swap_lock); +} + +void hibernation_thaw_swap(void) +{ + spin_lock(&swap_lock); + if (swap_for_hibernation) { + printk(KERN_INFO "PM: Thaw Swap\n"); + swap_for_hibernation = false; + } + spin_unlock(&swap_lock); +} + +/* + * Because updateing swap_map[] can make not-saved-status-change, + * we use our own easy allocator. + * Please see kernel/power/swap.c, Used swaps are recorded into + * RB-tree. + */ +swp_entry_t get_swap_for_hibernation(int type) +{ + pgoff_t off; + swp_entry_t val = {0}; + struct swap_info_struct *si; + + spin_lock(&swap_lock); + + si = swap_info[type]; + if (!si || !(si->flags & SWP_WRITEOK)) + goto done; + + for (off = hibernation_offset[type]; off < si->max; ++off) { + if (!si->swap_map[off]) + break; + } + if (off < si->max) { + val = swp_entry(type, off); + hibernation_offset[type] = off + 1; + } +done: + spin_unlock(&swap_lock); + return val; +} + +void swap_free_for_hibernation(swp_entry_t ent) +{ + /* Nothing to do */ +} + /* * Find the swap type that corresponds to given device (if any). * diff --git a/mm/truncate.c b/mm/truncate.c index 937571b8b23..ba887bff48c 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -541,28 +541,48 @@ void truncate_pagecache(struct inode *inode, loff_t old, loff_t new) EXPORT_SYMBOL(truncate_pagecache); /** + * truncate_setsize - update inode and pagecache for a new file size + * @inode: inode + * @newsize: new file size + * + * truncate_setsize updastes i_size update and performs pagecache + * truncation (if necessary) for a file size updates. It will be + * typically be called from the filesystem's setattr function when + * ATTR_SIZE is passed in. + * + * Must be called with inode_mutex held and after all filesystem + * specific block truncation has been performed. + */ +void truncate_setsize(struct inode *inode, loff_t newsize) +{ + loff_t oldsize; + + oldsize = inode->i_size; + i_size_write(inode, newsize); + + truncate_pagecache(inode, oldsize, newsize); +} +EXPORT_SYMBOL(truncate_setsize); + +/** * vmtruncate - unmap mappings "freed" by truncate() syscall * @inode: inode of the file used * @offset: file offset to start truncating * - * NOTE! We have to be ready to update the memory sharing - * between the file and the memory map for a potential last - * incomplete page. Ugly, but necessary. - * - * This function is deprecated and simple_setsize or truncate_pagecache - * should be used instead. + * This function is deprecated and truncate_setsize or truncate_pagecache + * should be used instead, together with filesystem specific block truncation. */ int vmtruncate(struct inode *inode, loff_t offset) { int error; - error = simple_setsize(inode, offset); + error = inode_newsize_ok(inode, offset); if (error) return error; + truncate_setsize(inode, offset); if (inode->i_op->truncate) inode->i_op->truncate(inode); - - return error; + return 0; } EXPORT_SYMBOL(vmtruncate); diff --git a/mm/util.c b/mm/util.c index f5712e8964b..4735ea48181 100644 --- a/mm/util.c +++ b/mm/util.c @@ -225,15 +225,10 @@ char *strndup_user(const char __user *s, long n) if (length > n) return ERR_PTR(-EINVAL); - p = kmalloc(length, GFP_KERNEL); + p = memdup_user(s, length); - if (!p) - return ERR_PTR(-ENOMEM); - - if (copy_from_user(p, s, length)) { - kfree(p); - return ERR_PTR(-EFAULT); - } + if (IS_ERR(p)) + return p; p[length - 1] = '\0'; diff --git a/mm/vmalloc.c b/mm/vmalloc.c index b7e314b1009..6b8889da69a 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -31,6 +31,7 @@ #include <asm/tlbflush.h> #include <asm/shmparam.h> +bool vmap_lazy_unmap __read_mostly = true; /*** Page table manipulation functions ***/ @@ -502,6 +503,9 @@ static unsigned long lazy_max_pages(void) { unsigned int log; + if (!vmap_lazy_unmap) + return 0; + log = fls(num_online_cpus()); return log * (32UL * 1024 * 1024 / PAGE_SIZE); @@ -732,7 +736,7 @@ static struct vmap_block *new_vmap_block(gfp_t gfp_mask) node, gfp_mask); if (unlikely(IS_ERR(va))) { kfree(vb); - return ERR_PTR(PTR_ERR(va)); + return ERR_CAST(va); } err = radix_tree_preload(gfp_mask); @@ -2437,8 +2441,11 @@ static int vmalloc_open(struct inode *inode, struct file *file) unsigned int *ptr = NULL; int ret; - if (NUMA_BUILD) + if (NUMA_BUILD) { ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL); + if (ptr == NULL) + return -ENOMEM; + } ret = seq_open(file, &vmalloc_op); if (!ret) { struct seq_file *m = file->private_data; diff --git a/mm/vmscan.c b/mm/vmscan.c index b94fe1b3da4..c391c320dba 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -48,6 +48,9 @@ #include "internal.h" +#define CREATE_TRACE_POINTS +#include <trace/events/vmscan.h> + struct scan_control { /* Incremented by the number of inactive pages that were scanned */ unsigned long nr_scanned; @@ -398,6 +401,8 @@ static pageout_t pageout(struct page *page, struct address_space *mapping, /* synchronous write or broken a_ops? */ ClearPageReclaim(page); } + trace_mm_vmscan_writepage(page, + trace_reclaim_flags(page, sync_writeback)); inc_zone_page_state(page, NR_VMSCAN_WRITE); return PAGE_SUCCESS; } @@ -617,6 +622,24 @@ static enum page_references page_check_references(struct page *page, return PAGEREF_RECLAIM; } +static noinline_for_stack void free_page_list(struct list_head *free_pages) +{ + struct pagevec freed_pvec; + struct page *page, *tmp; + + pagevec_init(&freed_pvec, 1); + + list_for_each_entry_safe(page, tmp, free_pages, lru) { + list_del(&page->lru); + if (!pagevec_add(&freed_pvec, page)) { + __pagevec_free(&freed_pvec); + pagevec_reinit(&freed_pvec); + } + } + + pagevec_free(&freed_pvec); +} + /* * shrink_page_list() returns the number of reclaimed pages */ @@ -625,13 +648,12 @@ static unsigned long shrink_page_list(struct list_head *page_list, enum pageout_io sync_writeback) { LIST_HEAD(ret_pages); - struct pagevec freed_pvec; + LIST_HEAD(free_pages); int pgactivate = 0; unsigned long nr_reclaimed = 0; cond_resched(); - pagevec_init(&freed_pvec, 1); while (!list_empty(page_list)) { enum page_references references; struct address_space *mapping; @@ -806,10 +828,12 @@ static unsigned long shrink_page_list(struct list_head *page_list, __clear_page_locked(page); free_it: nr_reclaimed++; - if (!pagevec_add(&freed_pvec, page)) { - __pagevec_free(&freed_pvec); - pagevec_reinit(&freed_pvec); - } + + /* + * Is there need to periodically free_page_list? It would + * appear not as the counts should be low + */ + list_add(&page->lru, &free_pages); continue; cull_mlocked: @@ -832,9 +856,10 @@ keep: list_add(&page->lru, &ret_pages); VM_BUG_ON(PageLRU(page) || PageUnevictable(page)); } + + free_page_list(&free_pages); + list_splice(&ret_pages, page_list); - if (pagevec_count(&freed_pvec)) - __pagevec_free(&freed_pvec); count_vm_events(PGACTIVATE, pgactivate); return nr_reclaimed; } @@ -916,6 +941,9 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, unsigned long *scanned, int order, int mode, int file) { unsigned long nr_taken = 0; + unsigned long nr_lumpy_taken = 0; + unsigned long nr_lumpy_dirty = 0; + unsigned long nr_lumpy_failed = 0; unsigned long scan; for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) { @@ -993,12 +1021,25 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, list_move(&cursor_page->lru, dst); mem_cgroup_del_lru(cursor_page); nr_taken++; + nr_lumpy_taken++; + if (PageDirty(cursor_page)) + nr_lumpy_dirty++; scan++; + } else { + if (mode == ISOLATE_BOTH && + page_count(cursor_page)) + nr_lumpy_failed++; } } } *scanned = scan; + + trace_mm_vmscan_lru_isolate(order, + nr_to_scan, scan, + nr_taken, + nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed, + mode); return nr_taken; } @@ -1035,7 +1076,8 @@ static unsigned long clear_active_flags(struct list_head *page_list, ClearPageActive(page); nr_active++; } - count[lru]++; + if (count) + count[lru]++; } return nr_active; @@ -1112,174 +1154,212 @@ static int too_many_isolated(struct zone *zone, int file, } /* - * shrink_inactive_list() is a helper for shrink_zone(). It returns the number - * of reclaimed pages + * TODO: Try merging with migrations version of putback_lru_pages */ -static unsigned long shrink_inactive_list(unsigned long max_scan, - struct zone *zone, struct scan_control *sc, - int priority, int file) +static noinline_for_stack void +putback_lru_pages(struct zone *zone, struct scan_control *sc, + unsigned long nr_anon, unsigned long nr_file, + struct list_head *page_list) { - LIST_HEAD(page_list); + struct page *page; struct pagevec pvec; - unsigned long nr_scanned = 0; - unsigned long nr_reclaimed = 0; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); - while (unlikely(too_many_isolated(zone, file, sc))) { - congestion_wait(BLK_RW_ASYNC, HZ/10); + pagevec_init(&pvec, 1); - /* We are about to die and free our memory. Return now. */ - if (fatal_signal_pending(current)) - return SWAP_CLUSTER_MAX; + /* + * Put back any unfreeable pages. + */ + spin_lock(&zone->lru_lock); + while (!list_empty(page_list)) { + int lru; + page = lru_to_page(page_list); + VM_BUG_ON(PageLRU(page)); + list_del(&page->lru); + if (unlikely(!page_evictable(page, NULL))) { + spin_unlock_irq(&zone->lru_lock); + putback_lru_page(page); + spin_lock_irq(&zone->lru_lock); + continue; + } + SetPageLRU(page); + lru = page_lru(page); + add_page_to_lru_list(zone, page, lru); + if (is_active_lru(lru)) { + int file = is_file_lru(lru); + reclaim_stat->recent_rotated[file]++; + } + if (!pagevec_add(&pvec, page)) { + spin_unlock_irq(&zone->lru_lock); + __pagevec_release(&pvec); + spin_lock_irq(&zone->lru_lock); + } } + __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon); + __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file); + + spin_unlock_irq(&zone->lru_lock); + pagevec_release(&pvec); +} +static noinline_for_stack void update_isolated_counts(struct zone *zone, + struct scan_control *sc, + unsigned long *nr_anon, + unsigned long *nr_file, + struct list_head *isolated_list) +{ + unsigned long nr_active; + unsigned int count[NR_LRU_LISTS] = { 0, }; + struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); - pagevec_init(&pvec, 1); + nr_active = clear_active_flags(isolated_list, count); + __count_vm_events(PGDEACTIVATE, nr_active); - lru_add_drain(); - spin_lock_irq(&zone->lru_lock); - do { - struct page *page; - unsigned long nr_taken; - unsigned long nr_scan; - unsigned long nr_freed; - unsigned long nr_active; - unsigned int count[NR_LRU_LISTS] = { 0, }; - int mode = sc->lumpy_reclaim_mode ? ISOLATE_BOTH : ISOLATE_INACTIVE; - unsigned long nr_anon; - unsigned long nr_file; + __mod_zone_page_state(zone, NR_ACTIVE_FILE, + -count[LRU_ACTIVE_FILE]); + __mod_zone_page_state(zone, NR_INACTIVE_FILE, + -count[LRU_INACTIVE_FILE]); + __mod_zone_page_state(zone, NR_ACTIVE_ANON, + -count[LRU_ACTIVE_ANON]); + __mod_zone_page_state(zone, NR_INACTIVE_ANON, + -count[LRU_INACTIVE_ANON]); - if (scanning_global_lru(sc)) { - nr_taken = isolate_pages_global(SWAP_CLUSTER_MAX, - &page_list, &nr_scan, - sc->order, mode, - zone, 0, file); - zone->pages_scanned += nr_scan; - if (current_is_kswapd()) - __count_zone_vm_events(PGSCAN_KSWAPD, zone, - nr_scan); - else - __count_zone_vm_events(PGSCAN_DIRECT, zone, - nr_scan); - } else { - nr_taken = mem_cgroup_isolate_pages(SWAP_CLUSTER_MAX, - &page_list, &nr_scan, - sc->order, mode, - zone, sc->mem_cgroup, - 0, file); - /* - * mem_cgroup_isolate_pages() keeps track of - * scanned pages on its own. - */ - } + *nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; + *nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; + __mod_zone_page_state(zone, NR_ISOLATED_ANON, *nr_anon); + __mod_zone_page_state(zone, NR_ISOLATED_FILE, *nr_file); - if (nr_taken == 0) - goto done; + reclaim_stat->recent_scanned[0] += *nr_anon; + reclaim_stat->recent_scanned[1] += *nr_file; +} - nr_active = clear_active_flags(&page_list, count); - __count_vm_events(PGDEACTIVATE, nr_active); +/* + * Returns true if the caller should wait to clean dirty/writeback pages. + * + * If we are direct reclaiming for contiguous pages and we do not reclaim + * everything in the list, try again and wait for writeback IO to complete. + * This will stall high-order allocations noticeably. Only do that when really + * need to free the pages under high memory pressure. + */ +static inline bool should_reclaim_stall(unsigned long nr_taken, + unsigned long nr_freed, + int priority, + struct scan_control *sc) +{ + int lumpy_stall_priority; - __mod_zone_page_state(zone, NR_ACTIVE_FILE, - -count[LRU_ACTIVE_FILE]); - __mod_zone_page_state(zone, NR_INACTIVE_FILE, - -count[LRU_INACTIVE_FILE]); - __mod_zone_page_state(zone, NR_ACTIVE_ANON, - -count[LRU_ACTIVE_ANON]); - __mod_zone_page_state(zone, NR_INACTIVE_ANON, - -count[LRU_INACTIVE_ANON]); + /* kswapd should not stall on sync IO */ + if (current_is_kswapd()) + return false; - nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; - nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; - __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon); - __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file); + /* Only stall on lumpy reclaim */ + if (!sc->lumpy_reclaim_mode) + return false; - reclaim_stat->recent_scanned[0] += nr_anon; - reclaim_stat->recent_scanned[1] += nr_file; + /* If we have relaimed everything on the isolated list, no stall */ + if (nr_freed == nr_taken) + return false; - spin_unlock_irq(&zone->lru_lock); + /* + * For high-order allocations, there are two stall thresholds. + * High-cost allocations stall immediately where as lower + * order allocations such as stacks require the scanning + * priority to be much higher before stalling. + */ + if (sc->order > PAGE_ALLOC_COSTLY_ORDER) + lumpy_stall_priority = DEF_PRIORITY; + else + lumpy_stall_priority = DEF_PRIORITY / 3; - nr_scanned += nr_scan; - nr_freed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC); + return priority <= lumpy_stall_priority; +} +/* + * shrink_inactive_list() is a helper for shrink_zone(). It returns the number + * of reclaimed pages + */ +static noinline_for_stack unsigned long +shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, + struct scan_control *sc, int priority, int file) +{ + LIST_HEAD(page_list); + unsigned long nr_scanned; + unsigned long nr_reclaimed = 0; + unsigned long nr_taken; + unsigned long nr_active; + unsigned long nr_anon; + unsigned long nr_file; + + while (unlikely(too_many_isolated(zone, file, sc))) { + congestion_wait(BLK_RW_ASYNC, HZ/10); + + /* We are about to die and free our memory. Return now. */ + if (fatal_signal_pending(current)) + return SWAP_CLUSTER_MAX; + } + + + lru_add_drain(); + spin_lock_irq(&zone->lru_lock); + + if (scanning_global_lru(sc)) { + nr_taken = isolate_pages_global(nr_to_scan, + &page_list, &nr_scanned, sc->order, + sc->lumpy_reclaim_mode ? + ISOLATE_BOTH : ISOLATE_INACTIVE, + zone, 0, file); + zone->pages_scanned += nr_scanned; + if (current_is_kswapd()) + __count_zone_vm_events(PGSCAN_KSWAPD, zone, + nr_scanned); + else + __count_zone_vm_events(PGSCAN_DIRECT, zone, + nr_scanned); + } else { + nr_taken = mem_cgroup_isolate_pages(nr_to_scan, + &page_list, &nr_scanned, sc->order, + sc->lumpy_reclaim_mode ? + ISOLATE_BOTH : ISOLATE_INACTIVE, + zone, sc->mem_cgroup, + 0, file); /* - * If we are direct reclaiming for contiguous pages and we do - * not reclaim everything in the list, try again and wait - * for IO to complete. This will stall high-order allocations - * but that should be acceptable to the caller + * mem_cgroup_isolate_pages() keeps track of + * scanned pages on its own. */ - if (nr_freed < nr_taken && !current_is_kswapd() && - sc->lumpy_reclaim_mode) { - congestion_wait(BLK_RW_ASYNC, HZ/10); + } - /* - * The attempt at page out may have made some - * of the pages active, mark them inactive again. - */ - nr_active = clear_active_flags(&page_list, count); - count_vm_events(PGDEACTIVATE, nr_active); + if (nr_taken == 0) { + spin_unlock_irq(&zone->lru_lock); + return 0; + } - nr_freed += shrink_page_list(&page_list, sc, - PAGEOUT_IO_SYNC); - } + update_isolated_counts(zone, sc, &nr_anon, &nr_file, &page_list); - nr_reclaimed += nr_freed; + spin_unlock_irq(&zone->lru_lock); - local_irq_disable(); - if (current_is_kswapd()) - __count_vm_events(KSWAPD_STEAL, nr_freed); - __count_zone_vm_events(PGSTEAL, zone, nr_freed); + nr_reclaimed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC); + + /* Check if we should syncronously wait for writeback */ + if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) { + congestion_wait(BLK_RW_ASYNC, HZ/10); - spin_lock(&zone->lru_lock); /* - * Put back any unfreeable pages. + * The attempt at page out may have made some + * of the pages active, mark them inactive again. */ - while (!list_empty(&page_list)) { - int lru; - page = lru_to_page(&page_list); - VM_BUG_ON(PageLRU(page)); - list_del(&page->lru); - if (unlikely(!page_evictable(page, NULL))) { - spin_unlock_irq(&zone->lru_lock); - putback_lru_page(page); - spin_lock_irq(&zone->lru_lock); - continue; - } - SetPageLRU(page); - lru = page_lru(page); - add_page_to_lru_list(zone, page, lru); - if (is_active_lru(lru)) { - int file = is_file_lru(lru); - reclaim_stat->recent_rotated[file]++; - } - if (!pagevec_add(&pvec, page)) { - spin_unlock_irq(&zone->lru_lock); - __pagevec_release(&pvec); - spin_lock_irq(&zone->lru_lock); - } - } - __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon); - __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file); + nr_active = clear_active_flags(&page_list, NULL); + count_vm_events(PGDEACTIVATE, nr_active); - } while (nr_scanned < max_scan); + nr_reclaimed += shrink_page_list(&page_list, sc, PAGEOUT_IO_SYNC); + } -done: - spin_unlock_irq(&zone->lru_lock); - pagevec_release(&pvec); - return nr_reclaimed; -} + local_irq_disable(); + if (current_is_kswapd()) + __count_vm_events(KSWAPD_STEAL, nr_reclaimed); + __count_zone_vm_events(PGSTEAL, zone, nr_reclaimed); -/* - * We are about to scan this zone at a certain priority level. If that priority - * level is smaller (ie: more urgent) than the previous priority, then note - * that priority level within the zone. This is done so that when the next - * process comes in to scan this zone, it will immediately start out at this - * priority level rather than having to build up its own scanning priority. - * Here, this priority affects only the reclaim-mapped threshold. - */ -static inline void note_zone_scanning_priority(struct zone *zone, int priority) -{ - if (priority < zone->prev_priority) - zone->prev_priority = priority; + putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list); + return nr_reclaimed; } /* @@ -1583,6 +1663,13 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, } /* + * With swappiness at 100, anonymous and file have the same priority. + * This scanning priority is essentially the inverse of IO cost. + */ + anon_prio = sc->swappiness; + file_prio = 200 - sc->swappiness; + + /* * OK, so we have swap space and a fair amount of page cache * pages. We use the recently rotated / recently scanned * ratios to determine how valuable each cache is. @@ -1593,28 +1680,18 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, * * anon in [0], file in [1] */ + spin_lock_irq(&zone->lru_lock); if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) { - spin_lock_irq(&zone->lru_lock); reclaim_stat->recent_scanned[0] /= 2; reclaim_stat->recent_rotated[0] /= 2; - spin_unlock_irq(&zone->lru_lock); } if (unlikely(reclaim_stat->recent_scanned[1] > file / 4)) { - spin_lock_irq(&zone->lru_lock); reclaim_stat->recent_scanned[1] /= 2; reclaim_stat->recent_rotated[1] /= 2; - spin_unlock_irq(&zone->lru_lock); } /* - * With swappiness at 100, anonymous and file have the same priority. - * This scanning priority is essentially the inverse of IO cost. - */ - anon_prio = sc->swappiness; - file_prio = 200 - sc->swappiness; - - /* * The amount of pressure on anon vs file pages is inversely * proportional to the fraction of recently scanned pages on * each list that were recently referenced and in active use. @@ -1624,6 +1701,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1); fp /= reclaim_stat->recent_rotated[1] + 1; + spin_unlock_irq(&zone->lru_lock); fraction[0] = ap; fraction[1] = fp; @@ -1729,13 +1807,12 @@ static void shrink_zone(int priority, struct zone *zone, static bool shrink_zones(int priority, struct zonelist *zonelist, struct scan_control *sc) { - enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask); struct zoneref *z; struct zone *zone; bool all_unreclaimable = true; - for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx, - sc->nodemask) { + for_each_zone_zonelist_nodemask(zone, z, zonelist, + gfp_zone(sc->gfp_mask), sc->nodemask) { if (!populated_zone(zone)) continue; /* @@ -1745,17 +1822,8 @@ static bool shrink_zones(int priority, struct zonelist *zonelist, if (scanning_global_lru(sc)) { if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) continue; - note_zone_scanning_priority(zone, priority); - if (zone->all_unreclaimable && priority != DEF_PRIORITY) continue; /* Let kswapd poll it */ - } else { - /* - * Ignore cpuset limitation here. We just want to reduce - * # of used pages by us regardless of memory shortage. - */ - mem_cgroup_note_reclaim_priority(sc->mem_cgroup, - priority); } shrink_zone(priority, zone, sc); @@ -1787,10 +1855,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, bool all_unreclaimable; unsigned long total_scanned = 0; struct reclaim_state *reclaim_state = current->reclaim_state; - unsigned long lru_pages = 0; struct zoneref *z; struct zone *zone; - enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask); unsigned long writeback_threshold; get_mems_allowed(); @@ -1798,18 +1864,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, if (scanning_global_lru(sc)) count_vm_event(ALLOCSTALL); - /* - * mem_cgroup will not do shrink_slab. - */ - if (scanning_global_lru(sc)) { - for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { - - if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) - continue; - - lru_pages += zone_reclaimable_pages(zone); - } - } for (priority = DEF_PRIORITY; priority >= 0; priority--) { sc->nr_scanned = 0; @@ -1821,6 +1875,15 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, * over limit cgroups */ if (scanning_global_lru(sc)) { + unsigned long lru_pages = 0; + for_each_zone_zonelist(zone, z, zonelist, + gfp_zone(sc->gfp_mask)) { + if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) + continue; + + lru_pages += zone_reclaimable_pages(zone); + } + shrink_slab(sc->nr_scanned, sc->gfp_mask, lru_pages); if (reclaim_state) { sc->nr_reclaimed += reclaim_state->reclaimed_slab; @@ -1861,17 +1924,6 @@ out: if (priority < 0) priority = 0; - if (scanning_global_lru(sc)) { - for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { - - if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) - continue; - - zone->prev_priority = priority; - } - } else - mem_cgroup_record_reclaim_priority(sc->mem_cgroup, priority); - delayacct_freepages_end(); put_mems_allowed(); @@ -1888,6 +1940,7 @@ out: unsigned long try_to_free_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *nodemask) { + unsigned long nr_reclaimed; struct scan_control sc = { .gfp_mask = gfp_mask, .may_writepage = !laptop_mode, @@ -1900,7 +1953,15 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order, .nodemask = nodemask, }; - return do_try_to_free_pages(zonelist, &sc); + trace_mm_vmscan_direct_reclaim_begin(order, + sc.may_writepage, + gfp_mask); + + nr_reclaimed = do_try_to_free_pages(zonelist, &sc); + + trace_mm_vmscan_direct_reclaim_end(nr_reclaimed); + + return nr_reclaimed; } #ifdef CONFIG_CGROUP_MEM_RES_CTLR @@ -1908,9 +1969,10 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order, unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem, gfp_t gfp_mask, bool noswap, unsigned int swappiness, - struct zone *zone, int nid) + struct zone *zone) { struct scan_control sc = { + .nr_to_reclaim = SWAP_CLUSTER_MAX, .may_writepage = !laptop_mode, .may_unmap = 1, .may_swap = !noswap, @@ -1918,13 +1980,13 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem, .order = 0, .mem_cgroup = mem, }; - nodemask_t nm = nodemask_of_node(nid); - sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) | (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK); - sc.nodemask = &nm; - sc.nr_reclaimed = 0; - sc.nr_scanned = 0; + + trace_mm_vmscan_memcg_softlimit_reclaim_begin(0, + sc.may_writepage, + sc.gfp_mask); + /* * NOTE: Although we can get the priority field, using it * here is not a good idea, since it limits the pages we can scan. @@ -1933,6 +1995,9 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem, * the priority and make it zero. */ shrink_zone(0, zone, &sc); + + trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed); + return sc.nr_reclaimed; } @@ -1942,6 +2007,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont, unsigned int swappiness) { struct zonelist *zonelist; + unsigned long nr_reclaimed; struct scan_control sc = { .may_writepage = !laptop_mode, .may_unmap = 1, @@ -1956,7 +2022,16 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont, sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) | (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK); zonelist = NODE_DATA(numa_node_id())->node_zonelists; - return do_try_to_free_pages(zonelist, &sc); + + trace_mm_vmscan_memcg_reclaim_begin(0, + sc.may_writepage, + sc.gfp_mask); + + nr_reclaimed = do_try_to_free_pages(zonelist, &sc); + + trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed); + + return nr_reclaimed; } #endif @@ -2028,22 +2103,12 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order) .order = order, .mem_cgroup = NULL, }; - /* - * temp_priority is used to remember the scanning priority at which - * this zone was successfully refilled to - * free_pages == high_wmark_pages(zone). - */ - int temp_priority[MAX_NR_ZONES]; - loop_again: total_scanned = 0; sc.nr_reclaimed = 0; sc.may_writepage = !laptop_mode; count_vm_event(PAGEOUTRUN); - for (i = 0; i < pgdat->nr_zones; i++) - temp_priority[i] = DEF_PRIORITY; - for (priority = DEF_PRIORITY; priority >= 0; priority--) { int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ unsigned long lru_pages = 0; @@ -2103,7 +2168,6 @@ loop_again: for (i = 0; i <= end_zone; i++) { struct zone *zone = pgdat->node_zones + i; int nr_slab; - int nid, zid; if (!populated_zone(zone)) continue; @@ -2111,18 +2175,14 @@ loop_again: if (zone->all_unreclaimable && priority != DEF_PRIORITY) continue; - temp_priority[i] = priority; sc.nr_scanned = 0; - note_zone_scanning_priority(zone, priority); - nid = pgdat->node_id; - zid = zone_idx(zone); /* * Call soft limit reclaim before calling shrink_zone. * For now we ignore the return value */ - mem_cgroup_soft_limit_reclaim(zone, order, sc.gfp_mask, - nid, zid); + mem_cgroup_soft_limit_reclaim(zone, order, sc.gfp_mask); + /* * We put equal pressure on every zone, unless one * zone has way too many pages free already. @@ -2186,16 +2246,6 @@ loop_again: break; } out: - /* - * Note within each zone the priority level at which this zone was - * brought into a happy state. So that the next thread which scans this - * zone will start out at that priority level. - */ - for (i = 0; i < pgdat->nr_zones; i++) { - struct zone *zone = pgdat->node_zones + i; - - zone->prev_priority = temp_priority[i]; - } if (!all_zones_ok) { cond_resched(); @@ -2299,9 +2349,10 @@ static int kswapd(void *p) * premature sleep. If not, then go fully * to sleep until explicitly woken up */ - if (!sleeping_prematurely(pgdat, order, remaining)) + if (!sleeping_prematurely(pgdat, order, remaining)) { + trace_mm_vmscan_kswapd_sleep(pgdat->node_id); schedule(); - else { + } else { if (remaining) count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY); else @@ -2321,8 +2372,10 @@ static int kswapd(void *p) * We can speed up thawing tasks if we don't call balance_pgdat * after returning from the refrigerator */ - if (!ret) + if (!ret) { + trace_mm_vmscan_kswapd_wake(pgdat->node_id, order); balance_pgdat(pgdat, order); + } } return 0; } @@ -2342,6 +2395,7 @@ void wakeup_kswapd(struct zone *zone, int order) return; if (pgdat->kswapd_max_order < order) pgdat->kswapd_max_order = order; + trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order); if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) return; if (!waitqueue_active(&pgdat->kswapd_wait)) @@ -2590,9 +2644,8 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) .swappiness = vm_swappiness, .order = order, }; - unsigned long slab_reclaimable; + unsigned long nr_slab_pages0, nr_slab_pages1; - disable_swap_token(); cond_resched(); /* * We need to be able to allocate from the reserves for RECLAIM_SWAP @@ -2611,14 +2664,13 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) */ priority = ZONE_RECLAIM_PRIORITY; do { - note_zone_scanning_priority(zone, priority); shrink_zone(priority, zone, &sc); priority--; } while (priority >= 0 && sc.nr_reclaimed < nr_pages); } - slab_reclaimable = zone_page_state(zone, NR_SLAB_RECLAIMABLE); - if (slab_reclaimable > zone->min_slab_pages) { + nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (nr_slab_pages0 > zone->min_slab_pages) { /* * shrink_slab() does not currently allow us to determine how * many pages were freed in this zone. So we take the current @@ -2629,17 +2681,27 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) * Note that shrink_slab will free memory on all zones and may * take a long time. */ - while (shrink_slab(sc.nr_scanned, gfp_mask, order) && - zone_page_state(zone, NR_SLAB_RECLAIMABLE) > - slab_reclaimable - nr_pages) - ; + for (;;) { + unsigned long lru_pages = zone_reclaimable_pages(zone); + + /* No reclaimable slab or very low memory pressure */ + if (!shrink_slab(sc.nr_scanned, gfp_mask, lru_pages)) + break; + + /* Freed enough memory */ + nr_slab_pages1 = zone_page_state(zone, + NR_SLAB_RECLAIMABLE); + if (nr_slab_pages1 + nr_pages <= nr_slab_pages0) + break; + } /* * Update nr_reclaimed by the number of slab pages we * reclaimed from this zone. */ - sc.nr_reclaimed += slab_reclaimable - - zone_page_state(zone, NR_SLAB_RECLAIMABLE); + nr_slab_pages1 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (nr_slab_pages1 < nr_slab_pages0) + sc.nr_reclaimed += nr_slab_pages0 - nr_slab_pages1; } p->reclaim_state = NULL; diff --git a/mm/vmstat.c b/mm/vmstat.c index 7759941d4e7..f389168f9a8 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -22,14 +22,14 @@ DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}}; EXPORT_PER_CPU_SYMBOL(vm_event_states); -static void sum_vm_events(unsigned long *ret, const struct cpumask *cpumask) +static void sum_vm_events(unsigned long *ret) { int cpu; int i; memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long)); - for_each_cpu(cpu, cpumask) { + for_each_online_cpu(cpu) { struct vm_event_state *this = &per_cpu(vm_event_states, cpu); for (i = 0; i < NR_VM_EVENT_ITEMS; i++) @@ -45,7 +45,7 @@ static void sum_vm_events(unsigned long *ret, const struct cpumask *cpumask) void all_vm_events(unsigned long *ret) { get_online_cpus(); - sum_vm_events(ret, cpu_online_mask); + sum_vm_events(ret); put_online_cpus(); } EXPORT_SYMBOL_GPL(all_vm_events); @@ -853,11 +853,9 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, } seq_printf(m, "\n all_unreclaimable: %u" - "\n prev_priority: %i" "\n start_pfn: %lu" "\n inactive_ratio: %u", zone->all_unreclaimable, - zone->prev_priority, zone->zone_start_pfn, zone->inactive_ratio); seq_putc(m, '\n'); |