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authorJiri Kosina <jkosina@suse.cz>2012-06-29 14:45:58 +0200
committerJiri Kosina <jkosina@suse.cz>2012-06-29 14:45:58 +0200
commit59f91e5dd0504dc0ebfaa0b6f3a55e6931f96266 (patch)
treeb913718405d44a921905ac71044fbde410256865 /mm/vmscan.c
parent57bdfdd80077addf518a9b90c4a66890efc4f70e (diff)
parent89abfab133ef1f5902abafb744df72793213ac19 (diff)
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Merge branch 'master' into for-next
Conflicts: include/linux/mmzone.h Synced with Linus' tree so that trivial patch can be applied on top of up-to-date code properly. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c306
1 files changed, 39 insertions, 267 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 3d1365c1786..8deb5f4da4d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -53,24 +53,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/vmscan.h>
-/*
- * reclaim_mode determines how the inactive list is shrunk
- * RECLAIM_MODE_SINGLE: Reclaim only order-0 pages
- * RECLAIM_MODE_ASYNC: Do not block
- * RECLAIM_MODE_SYNC: Allow blocking e.g. call wait_on_page_writeback
- * RECLAIM_MODE_LUMPYRECLAIM: For high-order allocations, take a reference
- * page from the LRU and reclaim all pages within a
- * naturally aligned range
- * RECLAIM_MODE_COMPACTION: For high-order allocations, reclaim a number of
- * order-0 pages and then compact the zone
- */
-typedef unsigned __bitwise__ reclaim_mode_t;
-#define RECLAIM_MODE_SINGLE ((__force reclaim_mode_t)0x01u)
-#define RECLAIM_MODE_ASYNC ((__force reclaim_mode_t)0x02u)
-#define RECLAIM_MODE_SYNC ((__force reclaim_mode_t)0x04u)
-#define RECLAIM_MODE_LUMPYRECLAIM ((__force reclaim_mode_t)0x08u)
-#define RECLAIM_MODE_COMPACTION ((__force reclaim_mode_t)0x10u)
-
struct scan_control {
/* Incremented by the number of inactive pages that were scanned */
unsigned long nr_scanned;
@@ -97,12 +79,6 @@ struct scan_control {
int order;
/*
- * Intend to reclaim enough continuous memory rather than reclaim
- * enough amount of memory. i.e, mode for high order allocation.
- */
- reclaim_mode_t reclaim_mode;
-
- /*
* The memory cgroup that hit its limit and as a result is the
* primary target of this reclaim invocation.
*/
@@ -164,35 +140,22 @@ static bool global_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup;
}
-
-static bool scanning_global_lru(struct mem_cgroup_zone *mz)
-{
- return !mz->mem_cgroup;
-}
#else
static bool global_reclaim(struct scan_control *sc)
{
return true;
}
-
-static bool scanning_global_lru(struct mem_cgroup_zone *mz)
-{
- return true;
-}
#endif
static struct zone_reclaim_stat *get_reclaim_stat(struct mem_cgroup_zone *mz)
{
- if (!scanning_global_lru(mz))
- return mem_cgroup_get_reclaim_stat(mz->mem_cgroup, mz->zone);
-
- return &mz->zone->reclaim_stat;
+ return &mem_cgroup_zone_lruvec(mz->zone, mz->mem_cgroup)->reclaim_stat;
}
static unsigned long zone_nr_lru_pages(struct mem_cgroup_zone *mz,
enum lru_list lru)
{
- if (!scanning_global_lru(mz))
+ if (!mem_cgroup_disabled())
return mem_cgroup_zone_nr_lru_pages(mz->mem_cgroup,
zone_to_nid(mz->zone),
zone_idx(mz->zone),
@@ -364,39 +327,6 @@ out:
return ret;
}
-static void set_reclaim_mode(int priority, struct scan_control *sc,
- bool sync)
-{
- reclaim_mode_t syncmode = sync ? RECLAIM_MODE_SYNC : RECLAIM_MODE_ASYNC;
-
- /*
- * Initially assume we are entering either lumpy reclaim or
- * reclaim/compaction.Depending on the order, we will either set the
- * sync mode or just reclaim order-0 pages later.
- */
- if (COMPACTION_BUILD)
- sc->reclaim_mode = RECLAIM_MODE_COMPACTION;
- else
- sc->reclaim_mode = RECLAIM_MODE_LUMPYRECLAIM;
-
- /*
- * Avoid using lumpy reclaim or reclaim/compaction if possible by
- * restricting when its set to either costly allocations or when
- * under memory pressure
- */
- if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
- sc->reclaim_mode |= syncmode;
- else if (sc->order && priority < DEF_PRIORITY - 2)
- sc->reclaim_mode |= syncmode;
- else
- sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
-}
-
-static void reset_reclaim_mode(struct scan_control *sc)
-{
- sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
-}
-
static inline int is_page_cache_freeable(struct page *page)
{
/*
@@ -416,10 +346,6 @@ static int may_write_to_queue(struct backing_dev_info *bdi,
return 1;
if (bdi == current->backing_dev_info)
return 1;
-
- /* lumpy reclaim for hugepage often need a lot of write */
- if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
- return 1;
return 0;
}
@@ -523,8 +449,7 @@ 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, sc->reclaim_mode));
+ trace_mm_vmscan_writepage(page, trace_reclaim_flags(page));
inc_zone_page_state(page, NR_VMSCAN_WRITE);
return PAGE_SUCCESS;
}
@@ -707,13 +632,10 @@ static enum page_references page_check_references(struct page *page,
int referenced_ptes, referenced_page;
unsigned long vm_flags;
- referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags);
+ referenced_ptes = page_referenced(page, 1, sc->target_mem_cgroup,
+ &vm_flags);
referenced_page = TestClearPageReferenced(page);
- /* Lumpy reclaim - ignore references */
- if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)
- return PAGEREF_RECLAIM;
-
/*
* Mlock lost the isolation race with us. Let try_to_unmap()
* move the page to the unevictable list.
@@ -722,7 +644,7 @@ static enum page_references page_check_references(struct page *page,
return PAGEREF_RECLAIM;
if (referenced_ptes) {
- if (PageAnon(page))
+ if (PageSwapBacked(page))
return PAGEREF_ACTIVATE;
/*
* All mapped pages start out with page table
@@ -813,19 +735,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
if (PageWriteback(page)) {
nr_writeback++;
- /*
- * Synchronous reclaim cannot queue pages for
- * writeback due to the possibility of stack overflow
- * but if it encounters a page under writeback, wait
- * for the IO to complete.
- */
- if ((sc->reclaim_mode & RECLAIM_MODE_SYNC) &&
- may_enter_fs)
- wait_on_page_writeback(page);
- else {
- unlock_page(page);
- goto keep_lumpy;
- }
+ unlock_page(page);
+ goto keep;
}
references = page_check_references(page, mz, sc);
@@ -908,7 +819,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto activate_locked;
case PAGE_SUCCESS:
if (PageWriteback(page))
- goto keep_lumpy;
+ goto keep;
if (PageDirty(page))
goto keep;
@@ -994,7 +905,6 @@ cull_mlocked:
try_to_free_swap(page);
unlock_page(page);
putback_lru_page(page);
- reset_reclaim_mode(sc);
continue;
activate_locked:
@@ -1007,8 +917,6 @@ activate_locked:
keep_locked:
unlock_page(page);
keep:
- reset_reclaim_mode(sc);
-keep_lumpy:
list_add(&page->lru, &ret_pages);
VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
}
@@ -1064,11 +972,7 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file)
if (!all_lru_mode && !!page_is_file_cache(page) != file)
return ret;
- /*
- * When this function is being called for lumpy reclaim, we
- * initially look into all LRU pages, active, inactive and
- * unevictable; only give shrink_page_list evictable pages.
- */
+ /* Do not give back unevictable pages for compaction */
if (PageUnevictable(page))
return ret;
@@ -1153,9 +1057,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
struct lruvec *lruvec;
struct list_head *src;
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;
int lru = LRU_BASE;
@@ -1168,10 +1069,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
struct page *page;
- unsigned long pfn;
- unsigned long end_pfn;
- unsigned long page_pfn;
- int zone_id;
page = lru_to_page(src);
prefetchw_prev_lru_page(page, src, flags);
@@ -1193,84 +1090,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
default:
BUG();
}
-
- if (!sc->order || !(sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM))
- continue;
-
- /*
- * Attempt to take all pages in the order aligned region
- * surrounding the tag page. Only take those pages of
- * the same active state as that tag page. We may safely
- * round the target page pfn down to the requested order
- * as the mem_map is guaranteed valid out to MAX_ORDER,
- * where that page is in a different zone we will detect
- * it from its zone id and abort this block scan.
- */
- zone_id = page_zone_id(page);
- page_pfn = page_to_pfn(page);
- pfn = page_pfn & ~((1 << sc->order) - 1);
- end_pfn = pfn + (1 << sc->order);
- for (; pfn < end_pfn; pfn++) {
- struct page *cursor_page;
-
- /* The target page is in the block, ignore it. */
- if (unlikely(pfn == page_pfn))
- continue;
-
- /* Avoid holes within the zone. */
- if (unlikely(!pfn_valid_within(pfn)))
- break;
-
- cursor_page = pfn_to_page(pfn);
-
- /* Check that we have not crossed a zone boundary. */
- if (unlikely(page_zone_id(cursor_page) != zone_id))
- break;
-
- /*
- * If we don't have enough swap space, reclaiming of
- * anon page which don't already have a swap slot is
- * pointless.
- */
- if (nr_swap_pages <= 0 && PageSwapBacked(cursor_page) &&
- !PageSwapCache(cursor_page))
- break;
-
- if (__isolate_lru_page(cursor_page, mode, file) == 0) {
- unsigned int isolated_pages;
-
- mem_cgroup_lru_del(cursor_page);
- list_move(&cursor_page->lru, dst);
- isolated_pages = hpage_nr_pages(cursor_page);
- nr_taken += isolated_pages;
- nr_lumpy_taken += isolated_pages;
- if (PageDirty(cursor_page))
- nr_lumpy_dirty += isolated_pages;
- scan++;
- pfn += isolated_pages - 1;
- } else {
- /*
- * Check if the page is freed already.
- *
- * We can't use page_count() as that
- * requires compound_head and we don't
- * have a pin on the page here. If a
- * page is tail, we may or may not
- * have isolated the head, so assume
- * it's not free, it'd be tricky to
- * track the head status without a
- * page pin.
- */
- if (!PageTail(cursor_page) &&
- !atomic_read(&cursor_page->_count))
- continue;
- break;
- }
- }
-
- /* If we break out of the loop above, lumpy reclaim failed */
- if (pfn < end_pfn)
- nr_lumpy_failed++;
}
*nr_scanned = scan;
@@ -1278,7 +1097,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
trace_mm_vmscan_lru_isolate(sc->order,
nr_to_scan, scan,
nr_taken,
- nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed,
mode, file);
return nr_taken;
}
@@ -1454,47 +1272,6 @@ update_isolated_counts(struct mem_cgroup_zone *mz,
}
/*
- * Returns true if a direct reclaim should wait on pages under writeback.
- *
- * 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;
-
- /* kswapd should not stall on sync IO */
- if (current_is_kswapd())
- return false;
-
- /* Only stall on lumpy reclaim */
- if (sc->reclaim_mode & RECLAIM_MODE_SINGLE)
- return false;
-
- /* If we have reclaimed everything on the isolated list, no stall */
- if (nr_freed == nr_taken)
- return false;
-
- /*
- * 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;
-
- return priority <= lumpy_stall_priority;
-}
-
-/*
* shrink_inactive_list() is a helper for shrink_zone(). It returns the number
* of reclaimed pages
*/
@@ -1522,10 +1299,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
return SWAP_CLUSTER_MAX;
}
- set_reclaim_mode(priority, sc, false);
- if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)
- isolate_mode |= ISOLATE_ACTIVE;
-
lru_add_drain();
if (!sc->may_unmap)
@@ -1556,13 +1329,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority,
&nr_dirty, &nr_writeback);
- /* Check if we should syncronously wait for writeback */
- if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
- set_reclaim_mode(priority, sc, true);
- nr_reclaimed += shrink_page_list(&page_list, mz, sc,
- priority, &nr_dirty, &nr_writeback);
- }
-
spin_lock_irq(&zone->lru_lock);
reclaim_stat->recent_scanned[0] += nr_anon;
@@ -1616,7 +1382,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
zone_idx(zone),
nr_scanned, nr_reclaimed,
priority,
- trace_shrink_flags(file, sc->reclaim_mode));
+ trace_shrink_flags(file));
return nr_reclaimed;
}
@@ -1695,8 +1461,6 @@ static void shrink_active_list(unsigned long nr_to_scan,
lru_add_drain();
- reset_reclaim_mode(sc);
-
if (!sc->may_unmap)
isolate_mode |= ISOLATE_UNMAPPED;
if (!sc->may_writepage)
@@ -1737,7 +1501,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
}
}
- if (page_referenced(page, 0, mz->mem_cgroup, &vm_flags)) {
+ if (page_referenced(page, 0, sc->target_mem_cgroup,
+ &vm_flags)) {
nr_rotated += hpage_nr_pages(page);
/*
* Identify referenced, file-backed active pages and
@@ -1811,7 +1576,7 @@ static int inactive_anon_is_low(struct mem_cgroup_zone *mz)
if (!total_swap_pages)
return 0;
- if (!scanning_global_lru(mz))
+ if (!mem_cgroup_disabled())
return mem_cgroup_inactive_anon_is_low(mz->mem_cgroup,
mz->zone);
@@ -1850,7 +1615,7 @@ static int inactive_file_is_low_global(struct zone *zone)
*/
static int inactive_file_is_low(struct mem_cgroup_zone *mz)
{
- if (!scanning_global_lru(mz))
+ if (!mem_cgroup_disabled())
return mem_cgroup_inactive_file_is_low(mz->mem_cgroup,
mz->zone);
@@ -1984,10 +1749,10 @@ static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
* proportional to the fraction of recently scanned pages on
* each list that were recently referenced and in active use.
*/
- ap = (anon_prio + 1) * (reclaim_stat->recent_scanned[0] + 1);
+ ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1);
ap /= reclaim_stat->recent_rotated[0] + 1;
- fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
+ fp = file_prio * (reclaim_stat->recent_scanned[1] + 1);
fp /= reclaim_stat->recent_rotated[1] + 1;
spin_unlock_irq(&mz->zone->lru_lock);
@@ -2000,7 +1765,7 @@ out:
unsigned long scan;
scan = zone_nr_lru_pages(mz, lru);
- if (priority || noswap) {
+ if (priority || noswap || !vmscan_swappiness(mz, sc)) {
scan >>= priority;
if (!scan && force_scan)
scan = SWAP_CLUSTER_MAX;
@@ -2010,23 +1775,35 @@ out:
}
}
+/* Use reclaim/compaction for costly allocs or under memory pressure */
+static bool in_reclaim_compaction(int priority, struct scan_control *sc)
+{
+ if (COMPACTION_BUILD && sc->order &&
+ (sc->order > PAGE_ALLOC_COSTLY_ORDER ||
+ priority < DEF_PRIORITY - 2))
+ return true;
+
+ return false;
+}
+
/*
- * Reclaim/compaction depends on a number of pages being freed. To avoid
- * disruption to the system, a small number of order-0 pages continue to be
- * rotated and reclaimed in the normal fashion. However, by the time we get
- * back to the allocator and call try_to_compact_zone(), we ensure that
- * there are enough free pages for it to be likely successful
+ * Reclaim/compaction is used for high-order allocation requests. It reclaims
+ * order-0 pages before compacting the zone. should_continue_reclaim() returns
+ * true if more pages should be reclaimed such that when the page allocator
+ * calls try_to_compact_zone() that it will have enough free pages to succeed.
+ * It will give up earlier than that if there is difficulty reclaiming pages.
*/
static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz,
unsigned long nr_reclaimed,
unsigned long nr_scanned,
+ int priority,
struct scan_control *sc)
{
unsigned long pages_for_compaction;
unsigned long inactive_lru_pages;
/* If not in reclaim/compaction mode, stop */
- if (!(sc->reclaim_mode & RECLAIM_MODE_COMPACTION))
+ if (!in_reclaim_compaction(priority, sc))
return false;
/* Consider stopping depending on scan and reclaim activity */
@@ -2128,7 +1905,8 @@ restart:
/* reclaim/compaction might need reclaim to continue */
if (should_continue_reclaim(mz, nr_reclaimed,
- sc->nr_scanned - nr_scanned, sc))
+ sc->nr_scanned - nr_scanned,
+ priority, sc))
goto restart;
throttle_vm_writeout(sc->gfp_mask);
@@ -2353,8 +2131,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
for (priority = DEF_PRIORITY; priority >= 0; priority--) {
sc->nr_scanned = 0;
- if (!priority)
- disable_swap_token(sc->target_mem_cgroup);
aborted_reclaim = shrink_zones(priority, zonelist, sc);
/*
@@ -2705,10 +2481,6 @@ loop_again:
unsigned long lru_pages = 0;
int has_under_min_watermark_zone = 0;
- /* The swap token gets in the way of swapout... */
- if (!priority)
- disable_swap_token(NULL);
-
all_zones_ok = 1;
balanced = 0;
@@ -3537,7 +3309,7 @@ int page_evictable(struct page *page, struct vm_area_struct *vma)
if (mapping_unevictable(page_mapping(page)))
return 0;
- if (PageMlocked(page) || (vma && is_mlocked_vma(vma, page)))
+ if (PageMlocked(page) || (vma && mlocked_vma_newpage(vma, page)))
return 0;
return 1;