diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/backing-dev.c | 52 | ||||
| -rw-r--r-- | mm/compaction.c | 156 | ||||
| -rw-r--r-- | mm/internal.h | 1 | ||||
| -rw-r--r-- | mm/mmap.c | 2 | ||||
| -rw-r--r-- | mm/page-writeback.c | 1 | ||||
| -rw-r--r-- | mm/page_alloc.c | 38 |
6 files changed, 132 insertions, 118 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 6b4718e2ee3..b41823cc05e 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -39,12 +39,6 @@ DEFINE_SPINLOCK(bdi_lock); LIST_HEAD(bdi_list); LIST_HEAD(bdi_pending_list); -static struct task_struct *sync_supers_tsk; -static struct timer_list sync_supers_timer; - -static int bdi_sync_supers(void *); -static void sync_supers_timer_fn(unsigned long); - void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2) { if (wb1 < wb2) { @@ -250,12 +244,6 @@ static int __init default_bdi_init(void) { int err; - sync_supers_tsk = kthread_run(bdi_sync_supers, NULL, "sync_supers"); - BUG_ON(IS_ERR(sync_supers_tsk)); - - setup_timer(&sync_supers_timer, sync_supers_timer_fn, 0); - bdi_arm_supers_timer(); - err = bdi_init(&default_backing_dev_info); if (!err) bdi_register(&default_backing_dev_info, NULL, "default"); @@ -270,46 +258,6 @@ int bdi_has_dirty_io(struct backing_dev_info *bdi) return wb_has_dirty_io(&bdi->wb); } -/* - * 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 thread individually. - */ -static int bdi_sync_supers(void *unused) -{ - set_user_nice(current, 0); - - while (!kthread_should_stop()) { - set_current_state(TASK_INTERRUPTIBLE); - schedule(); - - /* - * Do this periodically, like kupdated() did before. - */ - sync_supers(); - } - - return 0; -} - -void bdi_arm_supers_timer(void) -{ - unsigned long next; - - if (!dirty_writeback_interval) - return; - - next = msecs_to_jiffies(dirty_writeback_interval * 10) + jiffies; - mod_timer(&sync_supers_timer, round_jiffies_up(next)); -} - -static void sync_supers_timer_fn(unsigned long unused) -{ - wake_up_process(sync_supers_tsk); - bdi_arm_supers_timer(); -} - static void wakeup_timer_fn(unsigned long data) { struct backing_dev_info *bdi = (struct backing_dev_info *)data; diff --git a/mm/compaction.c b/mm/compaction.c index e78cb968842..7fcd3a52e68 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -51,6 +51,47 @@ static inline bool migrate_async_suitable(int migratetype) } /* + * Compaction requires the taking of some coarse locks that are potentially + * very heavily contended. Check if the process needs to be scheduled or + * if the lock is contended. For async compaction, back out in the event + * if contention is severe. For sync compaction, schedule. + * + * Returns true if the lock is held. + * Returns false if the lock is released and compaction should abort + */ +static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags, + bool locked, struct compact_control *cc) +{ + if (need_resched() || spin_is_contended(lock)) { + if (locked) { + spin_unlock_irqrestore(lock, *flags); + locked = false; + } + + /* async aborts if taking too long or contended */ + if (!cc->sync) { + if (cc->contended) + *cc->contended = true; + return false; + } + + cond_resched(); + if (fatal_signal_pending(current)) + return false; + } + + if (!locked) + spin_lock_irqsave(lock, *flags); + return true; +} + +static inline bool compact_trylock_irqsave(spinlock_t *lock, + unsigned long *flags, struct compact_control *cc) +{ + return compact_checklock_irqsave(lock, flags, false, cc); +} + +/* * Isolate free pages onto a private freelist. Caller must hold zone->lock. * If @strict is true, will abort returning 0 on any invalid PFNs or non-free * pages inside of the pageblock (even though it may still end up isolating @@ -173,7 +214,7 @@ isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn) } /* Update the number of anon and file isolated pages in the zone */ -static void acct_isolated(struct zone *zone, struct compact_control *cc) +static void acct_isolated(struct zone *zone, bool locked, struct compact_control *cc) { struct page *page; unsigned int count[2] = { 0, }; @@ -181,8 +222,14 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc) list_for_each_entry(page, &cc->migratepages, lru) count[!!page_is_file_cache(page)]++; - __mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]); - __mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]); + /* If locked we can use the interrupt unsafe versions */ + if (locked) { + __mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]); + __mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]); + } else { + mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]); + mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]); + } } /* Similar to reclaim, but different enough that they don't share logic */ @@ -228,6 +275,8 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, struct list_head *migratelist = &cc->migratepages; isolate_mode_t mode = 0; struct lruvec *lruvec; + unsigned long flags; + bool locked; /* * Ensure that there are not too many pages isolated from the LRU @@ -247,25 +296,22 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, /* Time to isolate some pages for migration */ cond_resched(); - spin_lock_irq(&zone->lru_lock); + spin_lock_irqsave(&zone->lru_lock, flags); + locked = true; for (; low_pfn < end_pfn; low_pfn++) { struct page *page; - bool locked = true; /* give a chance to irqs before checking need_resched() */ if (!((low_pfn+1) % SWAP_CLUSTER_MAX)) { - spin_unlock_irq(&zone->lru_lock); + spin_unlock_irqrestore(&zone->lru_lock, flags); locked = false; } - if (need_resched() || spin_is_contended(&zone->lru_lock)) { - if (locked) - spin_unlock_irq(&zone->lru_lock); - cond_resched(); - spin_lock_irq(&zone->lru_lock); - if (fatal_signal_pending(current)) - break; - } else if (!locked) - spin_lock_irq(&zone->lru_lock); + + /* Check if it is ok to still hold the lock */ + locked = compact_checklock_irqsave(&zone->lru_lock, &flags, + locked, cc); + if (!locked) + break; /* * migrate_pfn does not necessarily start aligned to a @@ -349,9 +395,10 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, } } - acct_isolated(zone, cc); + acct_isolated(zone, locked, cc); - spin_unlock_irq(&zone->lru_lock); + if (locked) + spin_unlock_irqrestore(&zone->lru_lock, flags); trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated); @@ -384,6 +431,20 @@ static bool suitable_migration_target(struct page *page) } /* + * Returns the start pfn of the last page block in a zone. This is the starting + * point for full compaction of a zone. Compaction searches for free pages from + * the end of each zone, while isolate_freepages_block scans forward inside each + * page block. + */ +static unsigned long start_free_pfn(struct zone *zone) +{ + unsigned long free_pfn; + free_pfn = zone->zone_start_pfn + zone->spanned_pages; + free_pfn &= ~(pageblock_nr_pages-1); + return free_pfn; +} + +/* * Based on information in the current compact_control, find blocks * suitable for isolating free pages from and then isolate them. */ @@ -422,17 +483,6 @@ static void isolate_freepages(struct zone *zone, pfn -= pageblock_nr_pages) { unsigned long isolated; - /* - * Skip ahead if another thread is compacting in the area - * simultaneously. If we wrapped around, we can only skip - * ahead if zone->compact_cached_free_pfn also wrapped to - * above our starting point. - */ - if (cc->order > 0 && (!cc->wrapped || - zone->compact_cached_free_pfn > - cc->start_free_pfn)) - pfn = min(pfn, zone->compact_cached_free_pfn); - if (!pfn_valid(pfn)) continue; @@ -458,7 +508,16 @@ static void isolate_freepages(struct zone *zone, * are disabled */ isolated = 0; - spin_lock_irqsave(&zone->lock, flags); + + /* + * The zone lock must be held to isolate freepages. This + * unfortunately this is a very coarse lock and can be + * heavily contended if there are parallel allocations + * or parallel compactions. For async compaction do not + * spin on the lock + */ + if (!compact_trylock_irqsave(&zone->lock, &flags, cc)) + break; if (suitable_migration_target(page)) { end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn); isolated = isolate_freepages_block(pfn, end_pfn, @@ -474,7 +533,15 @@ static void isolate_freepages(struct zone *zone, */ if (isolated) { high_pfn = max(high_pfn, pfn); - if (cc->order > 0) + + /* + * If the free scanner has wrapped, update + * compact_cached_free_pfn to point to the highest + * pageblock with free pages. This reduces excessive + * scanning of full pageblocks near the end of the + * zone + */ + if (cc->order > 0 && cc->wrapped) zone->compact_cached_free_pfn = high_pfn; } } @@ -484,6 +551,11 @@ static void isolate_freepages(struct zone *zone, cc->free_pfn = high_pfn; cc->nr_freepages = nr_freepages; + + /* If compact_cached_free_pfn is reset then set it now */ + if (cc->order > 0 && !cc->wrapped && + zone->compact_cached_free_pfn == start_free_pfn(zone)) + zone->compact_cached_free_pfn = high_pfn; } /* @@ -570,20 +642,6 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, return ISOLATE_SUCCESS; } -/* - * Returns the start pfn of the last page block in a zone. This is the starting - * point for full compaction of a zone. Compaction searches for free pages from - * the end of each zone, while isolate_freepages_block scans forward inside each - * page block. - */ -static unsigned long start_free_pfn(struct zone *zone) -{ - unsigned long free_pfn; - free_pfn = zone->zone_start_pfn + zone->spanned_pages; - free_pfn &= ~(pageblock_nr_pages-1); - return free_pfn; -} - static int compact_finished(struct zone *zone, struct compact_control *cc) { @@ -771,7 +829,7 @@ out: static unsigned long compact_zone_order(struct zone *zone, int order, gfp_t gfp_mask, - bool sync) + bool sync, bool *contended) { struct compact_control cc = { .nr_freepages = 0, @@ -780,6 +838,7 @@ static unsigned long compact_zone_order(struct zone *zone, .migratetype = allocflags_to_migratetype(gfp_mask), .zone = zone, .sync = sync, + .contended = contended, }; INIT_LIST_HEAD(&cc.freepages); INIT_LIST_HEAD(&cc.migratepages); @@ -801,7 +860,7 @@ int sysctl_extfrag_threshold = 500; */ unsigned long try_to_compact_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *nodemask, - bool sync) + bool sync, bool *contended) { enum zone_type high_zoneidx = gfp_zone(gfp_mask); int may_enter_fs = gfp_mask & __GFP_FS; @@ -825,7 +884,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, nodemask) { int status; - status = compact_zone_order(zone, order, gfp_mask, sync); + status = compact_zone_order(zone, order, gfp_mask, sync, + contended); rc = max(status, rc); /* If a normal allocation would succeed, stop compacting */ @@ -861,7 +921,7 @@ static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) if (cc->order > 0) { int ok = zone_watermark_ok(zone, cc->order, low_wmark_pages(zone), 0, 0); - if (ok && cc->order > zone->compact_order_failed) + if (ok && cc->order >= zone->compact_order_failed) zone->compact_order_failed = cc->order + 1; /* Currently async compaction is never deferred. */ else if (!ok && cc->sync) diff --git a/mm/internal.h b/mm/internal.h index 3314f79d775..b8c91b342e2 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -130,6 +130,7 @@ struct compact_control { int order; /* order a direct compactor needs */ int migratetype; /* MOVABLE, RECLAIMABLE etc */ struct zone *zone; + bool *contended; /* True if a lock was contended */ }; unsigned long diff --git a/mm/mmap.c b/mm/mmap.c index e3e86914f11..9adee9fc0d8 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2309,7 +2309,7 @@ void exit_mmap(struct mm_struct *mm) } vm_unacct_memory(nr_accounted); - BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT); + WARN_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT); } /* Insert vm structure into process list sorted by address diff --git a/mm/page-writeback.c b/mm/page-writeback.c index e5363f34e02..5ad5ce23c1e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1532,7 +1532,6 @@ int dirty_writeback_centisecs_handler(ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { proc_dointvec(table, write, buffer, length, ppos); - bdi_arm_supers_timer(); return 0; } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 009ac285fea..c66fb875104 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1928,6 +1928,17 @@ this_zone_full: zlc_active = 0; goto zonelist_scan; } + + if (page) + /* + * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was + * necessary to allocate the page. The expectation is + * that the caller is taking steps that will free more + * memory. The caller should avoid the page being used + * for !PFMEMALLOC purposes. + */ + page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS); + return page; } @@ -2091,7 +2102,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist, enum zone_type high_zoneidx, nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, int migratetype, bool sync_migration, - bool *deferred_compaction, + bool *contended_compaction, bool *deferred_compaction, unsigned long *did_some_progress) { struct page *page; @@ -2106,7 +2117,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, current->flags |= PF_MEMALLOC; *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask, - nodemask, sync_migration); + nodemask, sync_migration, + contended_compaction); current->flags &= ~PF_MEMALLOC; if (*did_some_progress != COMPACT_SKIPPED) { @@ -2152,7 +2164,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist, enum zone_type high_zoneidx, nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, int migratetype, bool sync_migration, - bool *deferred_compaction, + bool *contended_compaction, bool *deferred_compaction, unsigned long *did_some_progress) { return NULL; @@ -2325,6 +2337,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, unsigned long did_some_progress; bool sync_migration = false; bool deferred_compaction = false; + bool contended_compaction = false; /* * In the slowpath, we sanity check order to avoid ever trying to @@ -2389,14 +2402,6 @@ rebalance: zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); if (page) { - /* - * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was - * necessary to allocate the page. The expectation is - * that the caller is taking steps that will free more - * memory. The caller should avoid the page being used - * for !PFMEMALLOC purposes. - */ - page->pfmemalloc = true; goto got_pg; } } @@ -2422,6 +2427,7 @@ rebalance: nodemask, alloc_flags, preferred_zone, migratetype, sync_migration, + &contended_compaction, &deferred_compaction, &did_some_progress); if (page) @@ -2431,10 +2437,11 @@ rebalance: /* * If compaction is deferred for high-order allocations, it is because * sync compaction recently failed. In this is the case and the caller - * has requested the system not be heavily disrupted, fail the - * allocation now instead of entering direct reclaim + * requested a movable allocation that does not heavily disrupt the + * system then fail the allocation instead of entering direct reclaim. */ - if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD)) + if ((deferred_compaction || contended_compaction) && + (gfp_mask & __GFP_NO_KSWAPD)) goto nopage; /* Try direct reclaim and then allocating */ @@ -2505,6 +2512,7 @@ rebalance: nodemask, alloc_flags, preferred_zone, migratetype, sync_migration, + &contended_compaction, &deferred_compaction, &did_some_progress); if (page) @@ -2569,8 +2577,6 @@ retry_cpuset: page = __alloc_pages_slowpath(gfp_mask, order, zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); - else - page->pfmemalloc = false; trace_mm_page_alloc(page, order, gfp_mask, migratetype); |