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-rw-r--r--mm/vmscan.c539
1 files changed, 328 insertions, 211 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9a27c44aa32..ba8228e0a80 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -60,6 +60,9 @@ struct scan_control {
int may_writepage;
+ /* Can mapped pages be reclaimed? */
+ int may_unmap;
+
/* Can pages be swapped as part of reclaim? */
int may_swap;
@@ -78,6 +81,12 @@ struct scan_control {
/* Which cgroup do we reclaim from */
struct mem_cgroup *mem_cgroup;
+ /*
+ * Nodemask of nodes allowed by the caller. If NULL, all nodes
+ * are scanned.
+ */
+ nodemask_t *nodemask;
+
/* Pluggable isolate pages callback */
unsigned long (*isolate_pages)(unsigned long nr, struct list_head *dst,
unsigned long *scanned, int order, int mode,
@@ -214,8 +223,9 @@ unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
do_div(delta, lru_pages + 1);
shrinker->nr += delta;
if (shrinker->nr < 0) {
- printk(KERN_ERR "%s: nr=%ld\n",
- __func__, shrinker->nr);
+ printk(KERN_ERR "shrink_slab: %pF negative objects to "
+ "delete nr=%ld\n",
+ shrinker->shrink, shrinker->nr);
shrinker->nr = max_pass;
}
@@ -276,7 +286,7 @@ static inline int page_mapping_inuse(struct page *page)
static inline int is_page_cache_freeable(struct page *page)
{
- return page_count(page) - !!PagePrivate(page) == 2;
+ return page_count(page) - !!page_has_private(page) == 2;
}
static int may_write_to_queue(struct backing_dev_info *bdi)
@@ -360,7 +370,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
* Some data journaling orphaned pages can have
* page->mapping == NULL while being dirty with clean buffers.
*/
- if (PagePrivate(page)) {
+ if (page_has_private(page)) {
if (try_to_free_buffers(page)) {
ClearPageDirty(page);
printk("%s: orphaned page\n", __func__);
@@ -460,10 +470,11 @@ static int __remove_mapping(struct address_space *mapping, struct page *page)
swp_entry_t swap = { .val = page_private(page) };
__delete_from_swap_cache(page);
spin_unlock_irq(&mapping->tree_lock);
- swap_free(swap);
+ swapcache_free(swap, page);
} else {
__remove_from_page_cache(page);
spin_unlock_irq(&mapping->tree_lock);
+ mem_cgroup_uncharge_cache_page(page);
}
return 1;
@@ -502,7 +513,6 @@ int remove_mapping(struct address_space *mapping, struct page *page)
*
* lru_lock must not be held, interrupts must be enabled.
*/
-#ifdef CONFIG_UNEVICTABLE_LRU
void putback_lru_page(struct page *page)
{
int lru;
@@ -556,20 +566,6 @@ redo:
put_page(page); /* drop ref from isolate */
}
-#else /* CONFIG_UNEVICTABLE_LRU */
-
-void putback_lru_page(struct page *page)
-{
- int lru;
- VM_BUG_ON(PageLRU(page));
-
- lru = !!TestClearPageActive(page) + page_is_file_cache(page);
- lru_cache_add_lru(page, lru);
- put_page(page);
-}
-#endif /* CONFIG_UNEVICTABLE_LRU */
-
-
/*
* shrink_page_list() returns the number of reclaimed pages
*/
@@ -581,6 +577,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
struct pagevec freed_pvec;
int pgactivate = 0;
unsigned long nr_reclaimed = 0;
+ unsigned long vm_flags;
cond_resched();
@@ -606,7 +603,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
if (unlikely(!page_evictable(page, NULL)))
goto cull_mlocked;
- if (!sc->may_swap && page_mapped(page))
+ if (!sc->may_unmap && page_mapped(page))
goto keep_locked;
/* Double the slab pressure for mapped and swapcache pages */
@@ -631,10 +628,16 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto keep_locked;
}
- referenced = page_referenced(page, 1, sc->mem_cgroup);
- /* In active use or really unfreeable? Activate it. */
+ referenced = page_referenced(page, 1,
+ sc->mem_cgroup, &vm_flags);
+ /*
+ * In active use or really unfreeable? Activate it.
+ * If page which have PG_mlocked lost isoltation race,
+ * try_to_unmap moves it to unevictable list
+ */
if (sc->order <= PAGE_ALLOC_COSTLY_ORDER &&
- referenced && page_mapping_inuse(page))
+ referenced && page_mapping_inuse(page)
+ && !(vm_flags & VM_LOCKED))
goto activate_locked;
/*
@@ -720,7 +723,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
* process address space (page_count == 1) it can be freed.
* Otherwise, leave the page on the LRU so it is swappable.
*/
- if (PagePrivate(page)) {
+ if (page_has_private(page)) {
if (!try_to_release_page(page, sc->gfp_mask))
goto activate_locked;
if (!mapping && page_count(page) == 1) {
@@ -839,7 +842,6 @@ int __isolate_lru_page(struct page *page, int mode, int file)
*/
ClearPageLRU(page);
ret = 0;
- mem_cgroup_del_lru(page);
}
return ret;
@@ -887,12 +889,14 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
switch (__isolate_lru_page(page, mode, file)) {
case 0:
list_move(&page->lru, dst);
+ mem_cgroup_del_lru(page);
nr_taken++;
break;
case -EBUSY:
/* else it is being freed elsewhere */
list_move(&page->lru, src);
+ mem_cgroup_rotate_lru_list(page, page_lru(page));
continue;
default:
@@ -931,18 +935,11 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
/* Check that we have not crossed a zone boundary. */
if (unlikely(page_zone_id(cursor_page) != zone_id))
continue;
- switch (__isolate_lru_page(cursor_page, mode, file)) {
- case 0:
+ if (__isolate_lru_page(cursor_page, mode, file) == 0) {
list_move(&cursor_page->lru, dst);
+ mem_cgroup_del_lru(cursor_page);
nr_taken++;
scan++;
- break;
-
- case -EBUSY:
- /* else it is being freed elsewhere */
- list_move(&cursor_page->lru, src);
- default:
- break; /* ! on LRU or wrong list */
}
}
}
@@ -1049,6 +1046,19 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
unsigned long nr_scanned = 0;
unsigned long nr_reclaimed = 0;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+ int lumpy_reclaim = 0;
+
+ /*
+ * If we need a large contiguous chunk of memory, or have
+ * trouble getting a small set of contiguous pages, we
+ * will reclaim both active and inactive pages.
+ *
+ * We use the same threshold as pageout congestion_wait below.
+ */
+ if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+ lumpy_reclaim = 1;
+ else if (sc->order && priority < DEF_PRIORITY - 2)
+ lumpy_reclaim = 1;
pagevec_init(&pvec, 1);
@@ -1061,19 +1071,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
unsigned long nr_freed;
unsigned long nr_active;
unsigned int count[NR_LRU_LISTS] = { 0, };
- int mode = ISOLATE_INACTIVE;
-
- /*
- * If we need a large contiguous chunk of memory, or have
- * trouble getting a small set of contiguous pages, we
- * will reclaim both active and inactive pages.
- *
- * We use the same threshold as pageout congestion_wait below.
- */
- if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
- mode = ISOLATE_BOTH;
- else if (sc->order && priority < DEF_PRIORITY - 2)
- mode = ISOLATE_BOTH;
+ int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE;
nr_taken = sc->isolate_pages(sc->swap_cluster_max,
&page_list, &nr_scan, sc->order, mode,
@@ -1110,8 +1108,8 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
* but that should be acceptable to the caller
*/
if (nr_freed < nr_taken && !current_is_kswapd() &&
- sc->order > PAGE_ALLOC_COSTLY_ORDER) {
- congestion_wait(WRITE, HZ/10);
+ lumpy_reclaim) {
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
* The attempt at page out may have made some
@@ -1205,18 +1203,54 @@ static inline void note_zone_scanning_priority(struct zone *zone, int priority)
* But we had to alter page->flags anyway.
*/
+static void move_active_pages_to_lru(struct zone *zone,
+ struct list_head *list,
+ enum lru_list lru)
+{
+ unsigned long pgmoved = 0;
+ struct pagevec pvec;
+ struct page *page;
+
+ pagevec_init(&pvec, 1);
+
+ while (!list_empty(list)) {
+ page = lru_to_page(list);
+ prefetchw_prev_lru_page(page, list, flags);
+
+ VM_BUG_ON(PageLRU(page));
+ SetPageLRU(page);
+
+ VM_BUG_ON(!PageActive(page));
+ if (!is_active_lru(lru))
+ ClearPageActive(page); /* we are de-activating */
+
+ list_move(&page->lru, &zone->lru[lru].list);
+ mem_cgroup_add_lru_list(page, lru);
+ pgmoved++;
+
+ if (!pagevec_add(&pvec, page) || list_empty(list)) {
+ spin_unlock_irq(&zone->lru_lock);
+ if (buffer_heads_over_limit)
+ pagevec_strip(&pvec);
+ __pagevec_release(&pvec);
+ spin_lock_irq(&zone->lru_lock);
+ }
+ }
+ __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
+ if (!is_active_lru(lru))
+ __count_vm_events(PGDEACTIVATE, pgmoved);
+}
static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
struct scan_control *sc, int priority, int file)
{
unsigned long pgmoved;
- int pgdeactivate = 0;
unsigned long pgscanned;
+ unsigned long vm_flags;
LIST_HEAD(l_hold); /* The pages which were snipped off */
+ LIST_HEAD(l_active);
LIST_HEAD(l_inactive);
struct page *page;
- struct pagevec pvec;
- enum lru_list lru;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
lru_add_drain();
@@ -1233,13 +1267,14 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
}
reclaim_stat->recent_scanned[!!file] += pgmoved;
+ __count_zone_vm_events(PGREFILL, zone, pgscanned);
if (file)
__mod_zone_page_state(zone, NR_ACTIVE_FILE, -pgmoved);
else
__mod_zone_page_state(zone, NR_ACTIVE_ANON, -pgmoved);
spin_unlock_irq(&zone->lru_lock);
- pgmoved = 0;
+ pgmoved = 0; /* count referenced (mapping) mapped pages */
while (!list_empty(&l_hold)) {
cond_resched();
page = lru_to_page(&l_hold);
@@ -1252,64 +1287,44 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
/* page_referenced clears PageReferenced */
if (page_mapping_inuse(page) &&
- page_referenced(page, 0, sc->mem_cgroup))
+ page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
pgmoved++;
+ /*
+ * Identify referenced, file-backed active pages and
+ * give them one more trip around the active list. So
+ * that executable code get better chances to stay in
+ * memory under moderate memory pressure. Anon pages
+ * are not likely to be evicted by use-once streaming
+ * IO, plus JVM can create lots of anon VM_EXEC pages,
+ * so we ignore them here.
+ */
+ if ((vm_flags & VM_EXEC) && !PageAnon(page)) {
+ list_add(&page->lru, &l_active);
+ continue;
+ }
+ }
list_add(&page->lru, &l_inactive);
}
/*
- * Move the pages to the [file or anon] inactive list.
+ * Move pages back to the lru list.
*/
- pagevec_init(&pvec, 1);
- pgmoved = 0;
- lru = LRU_BASE + file * LRU_FILE;
-
spin_lock_irq(&zone->lru_lock);
/*
- * Count referenced pages from currently used mappings as
- * rotated, even though they are moved to the inactive list.
- * This helps balance scan pressure between file and anonymous
- * pages in get_scan_ratio.
+ * Count referenced pages from currently used mappings as rotated,
+ * even though only some of them are actually re-activated. This
+ * helps balance scan pressure between file and anonymous pages in
+ * get_scan_ratio.
*/
reclaim_stat->recent_rotated[!!file] += pgmoved;
- while (!list_empty(&l_inactive)) {
- page = lru_to_page(&l_inactive);
- prefetchw_prev_lru_page(page, &l_inactive, flags);
- VM_BUG_ON(PageLRU(page));
- SetPageLRU(page);
- VM_BUG_ON(!PageActive(page));
- ClearPageActive(page);
+ move_active_pages_to_lru(zone, &l_active,
+ LRU_ACTIVE + file * LRU_FILE);
+ move_active_pages_to_lru(zone, &l_inactive,
+ LRU_BASE + file * LRU_FILE);
- list_move(&page->lru, &zone->lru[lru].list);
- mem_cgroup_add_lru_list(page, lru);
- pgmoved++;
- if (!pagevec_add(&pvec, page)) {
- __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
- spin_unlock_irq(&zone->lru_lock);
- pgdeactivate += pgmoved;
- pgmoved = 0;
- if (buffer_heads_over_limit)
- pagevec_strip(&pvec);
- __pagevec_release(&pvec);
- spin_lock_irq(&zone->lru_lock);
- }
- }
- __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
- pgdeactivate += pgmoved;
- if (buffer_heads_over_limit) {
- spin_unlock_irq(&zone->lru_lock);
- pagevec_strip(&pvec);
- spin_lock_irq(&zone->lru_lock);
- }
- __count_zone_vm_events(PGREFILL, zone, pgscanned);
- __count_vm_events(PGDEACTIVATE, pgdeactivate);
spin_unlock_irq(&zone->lru_lock);
- if (vm_swap_full())
- pagevec_swap_free(&pvec);
-
- pagevec_release(&pvec);
}
static int inactive_anon_is_low_global(struct zone *zone)
@@ -1344,12 +1359,48 @@ static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
return low;
}
+static int inactive_file_is_low_global(struct zone *zone)
+{
+ unsigned long active, inactive;
+
+ active = zone_page_state(zone, NR_ACTIVE_FILE);
+ inactive = zone_page_state(zone, NR_INACTIVE_FILE);
+
+ return (active > inactive);
+}
+
+/**
+ * inactive_file_is_low - check if file pages need to be deactivated
+ * @zone: zone to check
+ * @sc: scan control of this context
+ *
+ * When the system is doing streaming IO, memory pressure here
+ * ensures that active file pages get deactivated, until more
+ * than half of the file pages are on the inactive list.
+ *
+ * Once we get to that situation, protect the system's working
+ * set from being evicted by disabling active file page aging.
+ *
+ * This uses a different ratio than the anonymous pages, because
+ * the page cache uses a use-once replacement algorithm.
+ */
+static int inactive_file_is_low(struct zone *zone, struct scan_control *sc)
+{
+ int low;
+
+ if (scanning_global_lru(sc))
+ low = inactive_file_is_low_global(zone);
+ else
+ low = mem_cgroup_inactive_file_is_low(sc->mem_cgroup);
+ return low;
+}
+
static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
struct zone *zone, struct scan_control *sc, int priority)
{
int file = is_file_lru(lru);
- if (lru == LRU_ACTIVE_FILE) {
+ if (lru == LRU_ACTIVE_FILE && inactive_file_is_low(zone, sc)) {
shrink_active_list(nr_to_scan, zone, sc, priority, file);
return 0;
}
@@ -1378,13 +1429,6 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
unsigned long ap, fp;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
- /* If we have no swap space, do not bother scanning anon pages. */
- if (nr_swap_pages <= 0) {
- percent[0] = 0;
- percent[1] = 100;
- return;
- }
-
anon = zone_nr_pages(zone, sc, LRU_ACTIVE_ANON) +
zone_nr_pages(zone, sc, LRU_INACTIVE_ANON);
file = zone_nr_pages(zone, sc, LRU_ACTIVE_FILE) +
@@ -1394,7 +1438,7 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
free = zone_page_state(zone, NR_FREE_PAGES);
/* If we have very few page cache pages,
force-scan anon pages. */
- if (unlikely(file + free <= zone->pages_high)) {
+ if (unlikely(file + free <= high_wmark_pages(zone))) {
percent[0] = 100;
percent[1] = 0;
return;
@@ -1449,6 +1493,26 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
percent[1] = 100 - percent[0];
}
+/*
+ * Smallish @nr_to_scan's are deposited in @nr_saved_scan,
+ * until we collected @swap_cluster_max pages to scan.
+ */
+static unsigned long nr_scan_try_batch(unsigned long nr_to_scan,
+ unsigned long *nr_saved_scan,
+ unsigned long swap_cluster_max)
+{
+ unsigned long nr;
+
+ *nr_saved_scan += nr_to_scan;
+ nr = *nr_saved_scan;
+
+ if (nr >= swap_cluster_max)
+ *nr_saved_scan = 0;
+ else
+ nr = 0;
+
+ return nr;
+}
/*
* This is a basic per-zone page freer. Used by both kswapd and direct reclaim.
@@ -1462,26 +1526,30 @@ static void shrink_zone(int priority, struct zone *zone,
enum lru_list l;
unsigned long nr_reclaimed = sc->nr_reclaimed;
unsigned long swap_cluster_max = sc->swap_cluster_max;
+ int noswap = 0;
- get_scan_ratio(zone, sc, percent);
+ /* If we have no swap space, do not bother scanning anon pages. */
+ if (!sc->may_swap || (nr_swap_pages <= 0)) {
+ noswap = 1;
+ percent[0] = 0;
+ percent[1] = 100;
+ } else
+ get_scan_ratio(zone, sc, percent);
for_each_evictable_lru(l) {
int file = is_file_lru(l);
- int scan;
+ unsigned long scan;
- scan = zone_page_state(zone, NR_LRU_BASE + l);
- if (priority) {
+ scan = zone_nr_pages(zone, sc, l);
+ if (priority || noswap) {
scan >>= priority;
scan = (scan * percent[file]) / 100;
}
- if (scanning_global_lru(sc)) {
- zone->lru[l].nr_scan += scan;
- nr[l] = zone->lru[l].nr_scan;
- if (nr[l] >= swap_cluster_max)
- zone->lru[l].nr_scan = 0;
- else
- nr[l] = 0;
- } else
+ if (scanning_global_lru(sc))
+ nr[l] = nr_scan_try_batch(scan,
+ &zone->lru[l].nr_saved_scan,
+ swap_cluster_max);
+ else
nr[l] = scan;
}
@@ -1515,7 +1583,7 @@ static void shrink_zone(int priority, struct zone *zone,
* Even if we did not try to evict anon pages at all, we want to
* rebalance the anon lru active/inactive ratio.
*/
- if (inactive_anon_is_low(zone, sc))
+ if (inactive_anon_is_low(zone, sc) && nr_swap_pages > 0)
shrink_active_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0);
throttle_vm_writeout(sc->gfp_mask);
@@ -1526,11 +1594,13 @@ static void shrink_zone(int priority, struct zone *zone,
* try to reclaim pages from zones which will satisfy the caller's allocation
* request.
*
- * We reclaim from a zone even if that zone is over pages_high. Because:
+ * We reclaim from a zone even if that zone is over high_wmark_pages(zone).
+ * Because:
* a) The caller may be trying to free *extra* pages to satisfy a higher-order
* allocation or
- * b) The zones may be over pages_high but they must go *over* pages_high to
- * satisfy the `incremental min' zone defense algorithm.
+ * b) The target zone may be at high_wmark_pages(zone) but the lower zones
+ * must go *over* high_wmark_pages(zone) to satisfy the `incremental min'
+ * zone defense algorithm.
*
* If a zone is deemed to be full of pinned pages then just give it a light
* scan then give up on it.
@@ -1543,7 +1613,8 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
struct zone *zone;
sc->all_unreclaimable = 1;
- for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+ for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
+ sc->nodemask) {
if (!populated_zone(zone))
continue;
/*
@@ -1649,13 +1720,13 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
*/
if (total_scanned > sc->swap_cluster_max +
sc->swap_cluster_max / 2) {
- wakeup_pdflush(laptop_mode ? 0 : total_scanned);
+ wakeup_flusher_threads(laptop_mode ? 0 : total_scanned);
sc->may_writepage = 1;
}
/* Take a nap, wait for some writeback to complete */
if (sc->nr_scanned && priority < DEF_PRIORITY - 2)
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
}
/* top priority shrink_zones still had more to do? don't OOM, then */
if (!sc->all_unreclaimable && scanning_global_lru(sc))
@@ -1688,17 +1759,19 @@ out:
}
unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
- gfp_t gfp_mask)
+ gfp_t gfp_mask, nodemask_t *nodemask)
{
struct scan_control sc = {
.gfp_mask = gfp_mask,
.may_writepage = !laptop_mode,
.swap_cluster_max = SWAP_CLUSTER_MAX,
+ .may_unmap = 1,
.may_swap = 1,
.swappiness = vm_swappiness,
.order = order,
.mem_cgroup = NULL,
.isolate_pages = isolate_pages_global,
+ .nodemask = nodemask,
};
return do_try_to_free_pages(zonelist, &sc);
@@ -1713,18 +1786,17 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
{
struct scan_control sc = {
.may_writepage = !laptop_mode,
- .may_swap = 1,
+ .may_unmap = 1,
+ .may_swap = !noswap,
.swap_cluster_max = SWAP_CLUSTER_MAX,
.swappiness = swappiness,
.order = 0,
.mem_cgroup = mem_cont,
.isolate_pages = mem_cgroup_isolate_pages,
+ .nodemask = NULL, /* we don't care the placement */
};
struct zonelist *zonelist;
- if (noswap)
- sc.may_swap = 0;
-
sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
zonelist = NODE_DATA(numa_node_id())->node_zonelists;
@@ -1734,7 +1806,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
/*
* For kswapd, balance_pgdat() will work across all this node's zones until
- * they are all at pages_high.
+ * they are all at high_wmark_pages(zone).
*
* Returns the number of pages which were actually freed.
*
@@ -1747,11 +1819,11 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
* the zone for when the problem goes away.
*
* kswapd scans the zones in the highmem->normal->dma direction. It skips
- * zones which have free_pages > pages_high, but once a zone is found to have
- * free_pages <= pages_high, we scan that zone and the lower zones regardless
- * of the number of free pages in the lower zones. This interoperates with
- * the page allocator fallback scheme to ensure that aging of pages is balanced
- * across the zones.
+ * zones which have free_pages > high_wmark_pages(zone), but once a zone is
+ * found to have free_pages <= high_wmark_pages(zone), we scan that zone and the
+ * lower zones regardless of the number of free pages in the lower zones. This
+ * interoperates with the page allocator fallback scheme to ensure that aging
+ * of pages is balanced across the zones.
*/
static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
{
@@ -1762,6 +1834,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
struct reclaim_state *reclaim_state = current->reclaim_state;
struct scan_control sc = {
.gfp_mask = GFP_KERNEL,
+ .may_unmap = 1,
.may_swap = 1,
.swap_cluster_max = SWAP_CLUSTER_MAX,
.swappiness = vm_swappiness,
@@ -1771,7 +1844,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
};
/*
* temp_priority is used to remember the scanning priority at which
- * this zone was successfully refilled to free_pages == pages_high.
+ * this zone was successfully refilled to
+ * free_pages == high_wmark_pages(zone).
*/
int temp_priority[MAX_NR_ZONES];
@@ -1816,8 +1890,8 @@ loop_again:
shrink_active_list(SWAP_CLUSTER_MAX, zone,
&sc, priority, 0);
- if (!zone_watermark_ok(zone, order, zone->pages_high,
- 0, 0)) {
+ if (!zone_watermark_ok(zone, order,
+ high_wmark_pages(zone), 0, 0)) {
end_zone = i;
break;
}
@@ -1851,8 +1925,8 @@ loop_again:
priority != DEF_PRIORITY)
continue;
- if (!zone_watermark_ok(zone, order, zone->pages_high,
- end_zone, 0))
+ if (!zone_watermark_ok(zone, order,
+ high_wmark_pages(zone), end_zone, 0))
all_zones_ok = 0;
temp_priority[i] = priority;
sc.nr_scanned = 0;
@@ -1861,8 +1935,8 @@ loop_again:
* We put equal pressure on every zone, unless one
* zone has way too many pages free already.
*/
- if (!zone_watermark_ok(zone, order, 8*zone->pages_high,
- end_zone, 0))
+ if (!zone_watermark_ok(zone, order,
+ 8*high_wmark_pages(zone), end_zone, 0))
shrink_zone(priority, zone, &sc);
reclaim_state->reclaimed_slab = 0;
nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL,
@@ -1891,7 +1965,7 @@ loop_again:
* another pass across the zones.
*/
if (total_scanned && priority < DEF_PRIORITY - 2)
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
* We do this so kswapd doesn't build up large priorities for
@@ -1963,7 +2037,9 @@ static int kswapd(void *p)
struct reclaim_state reclaim_state = {
.reclaimed_slab = 0,
};
- node_to_cpumask_ptr(cpumask, pgdat->node_id);
+ const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
+
+ lockdep_set_current_reclaim_state(GFP_KERNEL);
if (!cpumask_empty(cpumask))
set_cpus_allowed_ptr(tsk, cpumask);
@@ -2026,7 +2102,7 @@ void wakeup_kswapd(struct zone *zone, int order)
return;
pgdat = zone->zone_pgdat;
- if (zone_watermark_ok(zone, order, zone->pages_low, 0, 0))
+ if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0))
return;
if (pgdat->kswapd_max_order < order)
pgdat->kswapd_max_order = order;
@@ -2045,52 +2121,50 @@ unsigned long global_lru_pages(void)
+ global_page_state(NR_INACTIVE_FILE);
}
-#ifdef CONFIG_PM
+#ifdef CONFIG_HIBERNATION
/*
* Helper function for shrink_all_memory(). Tries to reclaim 'nr_pages' pages
- * from LRU lists system-wide, for given pass and priority, and returns the
- * number of reclaimed pages
+ * from LRU lists system-wide, for given pass and priority.
*
* For pass > 3 we also try to shrink the LRU lists that contain a few pages
*/
-static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
+static void shrink_all_zones(unsigned long nr_pages, int prio,
int pass, struct scan_control *sc)
{
struct zone *zone;
- unsigned long nr_to_scan, ret = 0;
- enum lru_list l;
-
- for_each_zone(zone) {
+ unsigned long nr_reclaimed = 0;
- if (!populated_zone(zone))
- continue;
+ for_each_populated_zone(zone) {
+ enum lru_list l;
if (zone_is_all_unreclaimable(zone) && prio != DEF_PRIORITY)
continue;
for_each_evictable_lru(l) {
+ enum zone_stat_item ls = NR_LRU_BASE + l;
+ unsigned long lru_pages = zone_page_state(zone, ls);
+
/* For pass = 0, we don't shrink the active list */
- if (pass == 0 &&
- (l == LRU_ACTIVE || l == LRU_ACTIVE_FILE))
+ if (pass == 0 && (l == LRU_ACTIVE_ANON ||
+ l == LRU_ACTIVE_FILE))
continue;
- zone->lru[l].nr_scan +=
- (zone_page_state(zone, NR_LRU_BASE + l)
- >> prio) + 1;
- if (zone->lru[l].nr_scan >= nr_pages || pass > 3) {
- zone->lru[l].nr_scan = 0;
- nr_to_scan = min(nr_pages,
- zone_page_state(zone,
- NR_LRU_BASE + l));
- ret += shrink_list(l, nr_to_scan, zone,
+ zone->lru[l].nr_saved_scan += (lru_pages >> prio) + 1;
+ if (zone->lru[l].nr_saved_scan >= nr_pages || pass > 3) {
+ unsigned long nr_to_scan;
+
+ zone->lru[l].nr_saved_scan = 0;
+ nr_to_scan = min(nr_pages, lru_pages);
+ nr_reclaimed += shrink_list(l, nr_to_scan, zone,
sc, prio);
- if (ret >= nr_pages)
- return ret;
+ if (nr_reclaimed >= nr_pages) {
+ sc->nr_reclaimed += nr_reclaimed;
+ return;
+ }
}
}
}
-
- return ret;
+ sc->nr_reclaimed += nr_reclaimed;
}
/*
@@ -2104,16 +2178,14 @@ static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
unsigned long shrink_all_memory(unsigned long nr_pages)
{
unsigned long lru_pages, nr_slab;
- unsigned long ret = 0;
int pass;
struct reclaim_state reclaim_state;
struct scan_control sc = {
.gfp_mask = GFP_KERNEL,
- .may_swap = 0,
- .swap_cluster_max = nr_pages,
+ .may_unmap = 0,
.may_writepage = 1,
- .swappiness = vm_swappiness,
.isolate_pages = isolate_pages_global,
+ .nr_reclaimed = 0,
};
current->reclaim_state = &reclaim_state;
@@ -2127,8 +2199,8 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
if (!reclaim_state.reclaimed_slab)
break;
- ret += reclaim_state.reclaimed_slab;
- if (ret >= nr_pages)
+ sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+ if (sc.nr_reclaimed >= nr_pages)
goto out;
nr_slab -= reclaim_state.reclaimed_slab;
@@ -2146,49 +2218,50 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
int prio;
/* Force reclaiming mapped pages in the passes #3 and #4 */
- if (pass > 2) {
- sc.may_swap = 1;
- sc.swappiness = 100;
- }
+ if (pass > 2)
+ sc.may_unmap = 1;
for (prio = DEF_PRIORITY; prio >= 0; prio--) {
- unsigned long nr_to_scan = nr_pages - ret;
+ unsigned long nr_to_scan = nr_pages - sc.nr_reclaimed;
sc.nr_scanned = 0;
- ret += shrink_all_zones(nr_to_scan, prio, pass, &sc);
- if (ret >= nr_pages)
+ sc.swap_cluster_max = nr_to_scan;
+ shrink_all_zones(nr_to_scan, prio, pass, &sc);
+ if (sc.nr_reclaimed >= nr_pages)
goto out;
reclaim_state.reclaimed_slab = 0;
shrink_slab(sc.nr_scanned, sc.gfp_mask,
global_lru_pages());
- ret += reclaim_state.reclaimed_slab;
- if (ret >= nr_pages)
+ sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+ if (sc.nr_reclaimed >= nr_pages)
goto out;
if (sc.nr_scanned && prio < DEF_PRIORITY - 2)
- congestion_wait(WRITE, HZ / 10);
+ congestion_wait(BLK_RW_ASYNC, HZ / 10);
}
}
/*
- * If ret = 0, we could not shrink LRUs, but there may be something
- * in slab caches
+ * If sc.nr_reclaimed = 0, we could not shrink LRUs, but there may be
+ * something in slab caches
*/
- if (!ret) {
+ if (!sc.nr_reclaimed) {
do {
reclaim_state.reclaimed_slab = 0;
shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
- ret += reclaim_state.reclaimed_slab;
- } while (ret < nr_pages && reclaim_state.reclaimed_slab > 0);
+ sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+ } while (sc.nr_reclaimed < nr_pages &&
+ reclaim_state.reclaimed_slab > 0);
}
+
out:
current->reclaim_state = NULL;
- return ret;
+ return sc.nr_reclaimed;
}
-#endif
+#endif /* CONFIG_HIBERNATION */
/* It's optimal to keep kswapds on the same CPUs as their memory, but
not required for correctness. So if the last cpu in a node goes
@@ -2202,7 +2275,9 @@ static int __devinit cpu_callback(struct notifier_block *nfb,
if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) {
for_each_node_state(nid, N_HIGH_MEMORY) {
pg_data_t *pgdat = NODE_DATA(nid);
- node_to_cpumask_ptr(mask, pgdat->node_id);
+ const struct cpumask *mask;
+
+ mask = cpumask_of_node(pgdat->node_id);
if (cpumask_any_and(cpu_online_mask, mask) < nr_cpu_ids)
/* One of our CPUs online: restore mask */
@@ -2280,6 +2355,48 @@ int sysctl_min_unmapped_ratio = 1;
*/
int sysctl_min_slab_ratio = 5;
+static inline unsigned long zone_unmapped_file_pages(struct zone *zone)
+{
+ unsigned long file_mapped = zone_page_state(zone, NR_FILE_MAPPED);
+ unsigned long file_lru = zone_page_state(zone, NR_INACTIVE_FILE) +
+ zone_page_state(zone, NR_ACTIVE_FILE);
+
+ /*
+ * It's possible for there to be more file mapped pages than
+ * accounted for by the pages on the file LRU lists because
+ * tmpfs pages accounted for as ANON can also be FILE_MAPPED
+ */
+ return (file_lru > file_mapped) ? (file_lru - file_mapped) : 0;
+}
+
+/* Work out how many page cache pages we can reclaim in this reclaim_mode */
+static long zone_pagecache_reclaimable(struct zone *zone)
+{
+ long nr_pagecache_reclaimable;
+ long delta = 0;
+
+ /*
+ * If RECLAIM_SWAP is set, then all file pages are considered
+ * potentially reclaimable. Otherwise, we have to worry about
+ * pages like swapcache and zone_unmapped_file_pages() provides
+ * a better estimate
+ */
+ if (zone_reclaim_mode & RECLAIM_SWAP)
+ nr_pagecache_reclaimable = zone_page_state(zone, NR_FILE_PAGES);
+ else
+ nr_pagecache_reclaimable = zone_unmapped_file_pages(zone);
+
+ /* If we can't clean pages, remove dirty pages from consideration */
+ if (!(zone_reclaim_mode & RECLAIM_WRITE))
+ delta += zone_page_state(zone, NR_FILE_DIRTY);
+
+ /* Watch for any possible underflows due to delta */
+ if (unlikely(delta > nr_pagecache_reclaimable))
+ delta = nr_pagecache_reclaimable;
+
+ return nr_pagecache_reclaimable - delta;
+}
+
/*
* Try to free up some pages from this zone through reclaim.
*/
@@ -2292,11 +2409,13 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
int priority;
struct scan_control sc = {
.may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
- .may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP),
+ .may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP),
+ .may_swap = 1,
.swap_cluster_max = max_t(unsigned long, nr_pages,
SWAP_CLUSTER_MAX),
.gfp_mask = gfp_mask,
.swappiness = vm_swappiness,
+ .order = order,
.isolate_pages = isolate_pages_global,
};
unsigned long slab_reclaimable;
@@ -2312,9 +2431,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
reclaim_state.reclaimed_slab = 0;
p->reclaim_state = &reclaim_state;
- if (zone_page_state(zone, NR_FILE_PAGES) -
- zone_page_state(zone, NR_FILE_MAPPED) >
- zone->min_unmapped_pages) {
+ if (zone_pagecache_reclaimable(zone) > zone->min_unmapped_pages) {
/*
* Free memory by calling shrink zone with increasing
* priorities until we have enough memory freed.
@@ -2372,20 +2489,18 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* if less than a specified percentage of the zone is used by
* unmapped file backed pages.
*/
- if (zone_page_state(zone, NR_FILE_PAGES) -
- zone_page_state(zone, NR_FILE_MAPPED) <= zone->min_unmapped_pages
- && zone_page_state(zone, NR_SLAB_RECLAIMABLE)
- <= zone->min_slab_pages)
- return 0;
+ if (zone_pagecache_reclaimable(zone) <= zone->min_unmapped_pages &&
+ zone_page_state(zone, NR_SLAB_RECLAIMABLE) <= zone->min_slab_pages)
+ return ZONE_RECLAIM_FULL;
if (zone_is_all_unreclaimable(zone))
- return 0;
+ return ZONE_RECLAIM_FULL;
/*
* Do not scan if the allocation should not be delayed.
*/
if (!(gfp_mask & __GFP_WAIT) || (current->flags & PF_MEMALLOC))
- return 0;
+ return ZONE_RECLAIM_NOSCAN;
/*
* Only run zone reclaim on the local zone or on zones that do not
@@ -2395,18 +2510,21 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
*/
node_id = zone_to_nid(zone);
if (node_state(node_id, N_CPU) && node_id != numa_node_id())
- return 0;
+ return ZONE_RECLAIM_NOSCAN;
if (zone_test_and_set_flag(zone, ZONE_RECLAIM_LOCKED))
- return 0;
+ return ZONE_RECLAIM_NOSCAN;
+
ret = __zone_reclaim(zone, gfp_mask, order);
zone_clear_flag(zone, ZONE_RECLAIM_LOCKED);
+ if (!ret)
+ count_vm_event(PGSCAN_ZONE_RECLAIM_FAILED);
+
return ret;
}
#endif
-#ifdef CONFIG_UNEVICTABLE_LRU
/*
* page_evictable - test whether a page is evictable
* @page: the page to test
@@ -2653,4 +2771,3 @@ void scan_unevictable_unregister_node(struct node *node)
sysdev_remove_file(&node->sysdev, &attr_scan_unevictable_pages);
}
-#endif