/* Number of pages freed so far during a call to shrink_zones() */
unsigned long nr_reclaimed;
+ /* How many pages shrink_list() should reclaim */
+ unsigned long nr_to_reclaim;
+
+ unsigned long hibernation_mode;
+
/* This context's GFP mask */
gfp_t gfp_mask;
/* Can pages be swapped as part of reclaim? */
int may_swap;
- /* This context's SWAP_CLUSTER_MAX. If freeing memory for
- * suspend, we effectively ignore SWAP_CLUSTER_MAX.
- * In this context, it doesn't matter that we scan the
- * whole list at once. */
- int swap_cluster_max;
-
int swappiness;
int all_unreclaimable;
return &zone->reclaim_stat;
}
-static unsigned long zone_nr_pages(struct zone *zone, struct scan_control *sc,
- enum lru_list lru)
+static unsigned long zone_nr_lru_pages(struct zone *zone,
+ struct scan_control *sc, enum lru_list lru)
{
if (!scanning_global_lru(sc))
return mem_cgroup_zone_nr_pages(sc->mem_cgroup, zone, lru);
static inline int is_page_cache_freeable(struct page *page)
{
- return page_count(page) - !!page_has_private(page) == 2;
+ /*
+ * A freeable page cache page is referenced only by the caller
+ * that isolated the page, the page cache radix tree and
+ * optional buffer heads at page->private.
+ */
+ return page_count(page) - page_has_private(page) == 2;
}
static int may_write_to_queue(struct backing_dev_info *bdi)
* stalls if we need to run get_block(). We could test
* PagePrivate for that.
*
- * If this process is currently in generic_file_write() against
+ * If this process is currently in __generic_file_aio_write() against
* this page's queue, we can perform writeback even if that
* will block.
*
* block, for some throttling. This happens by accident, because
* swap_backing_dev_info is bust: it doesn't reflect the
* congestion state of the swapdevs. Easy to fix, if needed.
- * See swapfile.c:page_queue_congested().
*/
if (!is_page_cache_freeable(page))
return PAGE_KEEP;
* unevictable page on [in]active list.
* We know how to handle that.
*/
- lru = active + page_is_file_cache(page);
+ lru = active + page_lru_base_type(page);
lru_cache_add_lru(page, lru);
} else {
/*
*/
lru = LRU_UNEVICTABLE;
add_page_to_unevictable_list(page);
+ /*
+ * When racing with an mlock clearing (page is
+ * unlocked), make sure that if the other thread does
+ * not observe our setting of PG_lru and fails
+ * isolation, we see PG_mlocked cleared below and move
+ * the page back to the evictable list.
+ *
+ * The other side is TestClearPageMlocked().
+ */
+ smp_mb();
}
/*
referenced = page_referenced(page, 1,
sc->mem_cgroup, &vm_flags);
- /* In active use or really unfreeable? Activate it. */
+ /*
+ * 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;
/*
* processes. Try to unmap it here.
*/
if (page_mapped(page) && mapping) {
- switch (try_to_unmap(page, 0)) {
+ switch (try_to_unmap(page, TTU_UNMAP)) {
case SWAP_FAIL:
goto activate_locked;
case SWAP_AGAIN:
if (mode != ISOLATE_BOTH && (!PageActive(page) != !mode))
return ret;
- if (mode != ISOLATE_BOTH && (!page_is_file_cache(page) != !file))
+ if (mode != ISOLATE_BOTH && page_is_file_cache(page) != file)
return ret;
/*
/* Check that we have not crossed a zone boundary. */
if (unlikely(page_zone_id(cursor_page) != zone_id))
continue;
+
+ /*
+ * 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 && PageAnon(cursor_page) &&
+ !PageSwapCache(cursor_page))
+ continue;
+
if (__isolate_lru_page(cursor_page, mode, file) == 0) {
list_move(&cursor_page->lru, dst);
- mem_cgroup_del_lru(page);
+ mem_cgroup_del_lru(cursor_page);
nr_taken++;
scan++;
}
if (file)
lru += LRU_FILE;
return isolate_lru_pages(nr, &z->lru[lru].list, dst, scanned, order,
- mode, !!file);
+ mode, file);
}
/*
struct page *page;
list_for_each_entry(page, page_list, lru) {
- lru = page_is_file_cache(page);
+ lru = page_lru_base_type(page);
if (PageActive(page)) {
lru += LRU_ACTIVE;
ClearPageActive(page);
}
/*
+ * Are there way too many processes in the direct reclaim path already?
+ */
+static int too_many_isolated(struct zone *zone, int file,
+ struct scan_control *sc)
+{
+ unsigned long inactive, isolated;
+
+ if (current_is_kswapd())
+ return 0;
+
+ if (!scanning_global_lru(sc))
+ return 0;
+
+ if (file) {
+ inactive = zone_page_state(zone, NR_INACTIVE_FILE);
+ isolated = zone_page_state(zone, NR_ISOLATED_FILE);
+ } else {
+ inactive = zone_page_state(zone, NR_INACTIVE_ANON);
+ isolated = zone_page_state(zone, NR_ISOLATED_ANON);
+ }
+
+ return isolated > inactive;
+}
+
+/*
* shrink_inactive_list() is a helper for shrink_zone(). It returns the number
* of reclaimed pages
*/
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
int lumpy_reclaim = 0;
+ 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;
+ }
+
/*
* If we need a large contiguous chunk of memory, or have
* trouble getting a small set of contiguous pages, we
unsigned long nr_active;
unsigned int count[NR_LRU_LISTS] = { 0, };
int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE;
+ unsigned long nr_anon;
+ unsigned long nr_file;
- nr_taken = sc->isolate_pages(sc->swap_cluster_max,
+ nr_taken = sc->isolate_pages(SWAP_CLUSTER_MAX,
&page_list, &nr_scan, sc->order, mode,
zone, sc->mem_cgroup, 0, file);
+
+ if (scanning_global_lru(sc)) {
+ 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);
+ }
+
+ if (nr_taken == 0)
+ goto done;
+
nr_active = clear_active_flags(&page_list, count);
__count_vm_events(PGDEACTIVATE, nr_active);
__mod_zone_page_state(zone, NR_INACTIVE_ANON,
-count[LRU_INACTIVE_ANON]);
- if (scanning_global_lru(sc))
- zone->pages_scanned += nr_scan;
+ 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);
- reclaim_stat->recent_scanned[0] += count[LRU_INACTIVE_ANON];
- reclaim_stat->recent_scanned[0] += count[LRU_ACTIVE_ANON];
- reclaim_stat->recent_scanned[1] += count[LRU_INACTIVE_FILE];
- reclaim_stat->recent_scanned[1] += count[LRU_ACTIVE_FILE];
+ reclaim_stat->recent_scanned[0] += nr_anon;
+ reclaim_stat->recent_scanned[1] += nr_file;
spin_unlock_irq(&zone->lru_lock);
*/
if (nr_freed < nr_taken && !current_is_kswapd() &&
lumpy_reclaim) {
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
* The attempt at page out may have made some
}
nr_reclaimed += nr_freed;
+
local_irq_disable();
- if (current_is_kswapd()) {
- __count_zone_vm_events(PGSCAN_KSWAPD, zone, nr_scan);
+ if (current_is_kswapd())
__count_vm_events(KSWAPD_STEAL, nr_freed);
- } else if (scanning_global_lru(sc))
- __count_zone_vm_events(PGSCAN_DIRECT, zone, nr_scan);
-
__count_zone_vm_events(PGSTEAL, zone, nr_freed);
- if (nr_taken == 0)
- goto done;
-
spin_lock(&zone->lru_lock);
/*
* Put back any unfreeable pages.
SetPageLRU(page);
lru = page_lru(page);
add_page_to_lru_list(zone, page, lru);
- if (PageActive(page)) {
- int file = !!page_is_file_cache(page);
+ if (is_active_lru(lru)) {
+ int file = is_file_lru(lru);
reclaim_stat->recent_rotated[file]++;
}
if (!pagevec_add(&pvec, page)) {
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);
+
} while (nr_scanned < max_scan);
- spin_unlock(&zone->lru_lock);
+
done:
- local_irq_enable();
+ spin_unlock_irq(&zone->lru_lock);
pagevec_release(&pvec);
return nr_reclaimed;
}
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++;
static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
struct scan_control *sc, int priority, int file)
{
- unsigned long pgmoved;
+ unsigned long nr_taken;
unsigned long pgscanned;
unsigned long vm_flags;
LIST_HEAD(l_hold); /* The pages which were snipped off */
LIST_HEAD(l_inactive);
struct page *page;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+ unsigned long nr_rotated = 0;
lru_add_drain();
spin_lock_irq(&zone->lru_lock);
- pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
+ nr_taken = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
ISOLATE_ACTIVE, zone,
sc->mem_cgroup, 1, file);
/*
if (scanning_global_lru(sc)) {
zone->pages_scanned += pgscanned;
}
- reclaim_stat->recent_scanned[!!file] += pgmoved;
+ reclaim_stat->recent_scanned[file] += nr_taken;
__count_zone_vm_events(PGREFILL, zone, pgscanned);
if (file)
- __mod_zone_page_state(zone, NR_ACTIVE_FILE, -pgmoved);
+ __mod_zone_page_state(zone, NR_ACTIVE_FILE, -nr_taken);
else
- __mod_zone_page_state(zone, NR_ACTIVE_ANON, -pgmoved);
+ __mod_zone_page_state(zone, NR_ACTIVE_ANON, -nr_taken);
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, nr_taken);
spin_unlock_irq(&zone->lru_lock);
- pgmoved = 0; /* count referenced (mapping) mapped pages */
while (!list_empty(&l_hold)) {
cond_resched();
page = lru_to_page(&l_hold);
/* page_referenced clears PageReferenced */
if (page_mapping_inuse(page) &&
page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
- pgmoved++;
+ nr_rotated++;
/*
* Identify referenced, file-backed active pages and
* give them one more trip around the active list. So
* IO, plus JVM can create lots of anon VM_EXEC pages,
* so we ignore them here.
*/
- if ((vm_flags & VM_EXEC) && !PageAnon(page)) {
+ if ((vm_flags & VM_EXEC) && page_is_file_cache(page)) {
list_add(&page->lru, &l_active);
continue;
}
}
+ ClearPageActive(page); /* we are de-activating */
list_add(&page->lru, &l_inactive);
}
* helps balance scan pressure between file and anonymous pages in
* get_scan_ratio.
*/
- reclaim_stat->recent_rotated[!!file] += pgmoved;
+ reclaim_stat->recent_rotated[file] += nr_rotated;
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);
-
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken);
spin_unlock_irq(&zone->lru_lock);
}
return low;
}
+static int inactive_list_is_low(struct zone *zone, struct scan_control *sc,
+ int file)
+{
+ if (file)
+ return inactive_file_is_low(zone, sc);
+ else
+ return inactive_anon_is_low(zone, sc);
+}
+
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 && inactive_file_is_low(zone, sc)) {
- shrink_active_list(nr_to_scan, zone, sc, priority, file);
+ if (is_active_lru(lru)) {
+ if (inactive_list_is_low(zone, sc, file))
+ shrink_active_list(nr_to_scan, zone, sc, priority, file);
return 0;
}
- if (lru == LRU_ACTIVE_ANON && inactive_anon_is_low(zone, sc)) {
- shrink_active_list(nr_to_scan, zone, sc, priority, file);
- return 0;
- }
return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
}
unsigned long ap, fp;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
- 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) +
- zone_nr_pages(zone, sc, LRU_INACTIVE_FILE);
+ anon = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
+ zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
+ file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
+ zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
if (scanning_global_lru(sc)) {
free = zone_page_state(zone, NR_FREE_PAGES);
* 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_saved_scan)
{
unsigned long nr;
*nr_saved_scan += nr_to_scan;
nr = *nr_saved_scan;
- if (nr >= swap_cluster_max)
+ if (nr >= SWAP_CLUSTER_MAX)
*nr_saved_scan = 0;
else
nr = 0;
unsigned long percent[2]; /* anon @ 0; file @ 1 */
enum lru_list l;
unsigned long nr_reclaimed = sc->nr_reclaimed;
- unsigned long swap_cluster_max = sc->swap_cluster_max;
+ unsigned long nr_to_reclaim = sc->nr_to_reclaim;
+ struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
int noswap = 0;
/* If we have no swap space, do not bother scanning anon pages. */
int file = is_file_lru(l);
unsigned long scan;
- scan = zone_nr_pages(zone, sc, l);
+ scan = zone_nr_lru_pages(zone, sc, l);
if (priority || noswap) {
scan >>= priority;
scan = (scan * percent[file]) / 100;
}
- 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;
+ nr[l] = nr_scan_try_batch(scan,
+ &reclaim_stat->nr_saved_scan[l]);
}
while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
nr[LRU_INACTIVE_FILE]) {
for_each_evictable_lru(l) {
if (nr[l]) {
- nr_to_scan = min(nr[l], swap_cluster_max);
+ nr_to_scan = min_t(unsigned long,
+ nr[l], SWAP_CLUSTER_MAX);
nr[l] -= nr_to_scan;
nr_reclaimed += shrink_list(l, nr_to_scan,
* with multiple processes reclaiming pages, the total
* freeing target can get unreasonably large.
*/
- if (nr_reclaimed > swap_cluster_max &&
- priority < DEF_PRIORITY && !current_is_kswapd())
+ if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY)
break;
}
*
* If the caller is !__GFP_FS then the probability of a failure is reasonably
* high - the zone may be full of dirty or under-writeback pages, which this
- * caller can't do much about. We kick pdflush and take explicit naps in the
- * hope that some of these pages can be written. But if the allocating task
- * holds filesystem locks which prevent writeout this might not work, and the
- * allocation attempt will fail.
+ * caller can't do much about. We kick the writeback threads and take explicit
+ * naps in the hope that some of these pages can be written. But if the
+ * allocating task holds filesystem locks which prevent writeout this might not
+ * work, and the allocation attempt will fail.
*
* returns: 0, if no pages reclaimed
* else, the number of pages reclaimed
struct zoneref *z;
struct zone *zone;
enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask);
+ unsigned long writeback_threshold;
delayacct_freepages_start();
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
- lru_pages += zone_lru_pages(zone);
+ lru_pages += zone_reclaimable_pages(zone);
}
}
}
}
total_scanned += sc->nr_scanned;
- if (sc->nr_reclaimed >= sc->swap_cluster_max) {
+ if (sc->nr_reclaimed >= sc->nr_to_reclaim) {
ret = sc->nr_reclaimed;
goto out;
}
* that's undesirable in laptop mode, where we *want* lumpy
* writeout. So in laptop mode, write out the whole world.
*/
- if (total_scanned > sc->swap_cluster_max +
- sc->swap_cluster_max / 2) {
- wakeup_pdflush(laptop_mode ? 0 : total_scanned);
+ writeback_threshold = sc->nr_to_reclaim + sc->nr_to_reclaim / 2;
+ if (total_scanned > writeback_threshold) {
+ 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);
+ if (!sc->hibernation_mode && sc->nr_scanned &&
+ priority < DEF_PRIORITY - 2)
+ 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))
struct scan_control sc = {
.gfp_mask = gfp_mask,
.may_writepage = !laptop_mode,
- .swap_cluster_max = SWAP_CLUSTER_MAX,
+ .nr_to_reclaim = SWAP_CLUSTER_MAX,
.may_unmap = 1,
.may_swap = 1,
.swappiness = vm_swappiness,
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+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 scan_control sc = {
+ .may_writepage = !laptop_mode,
+ .may_unmap = 1,
+ .may_swap = !noswap,
+ .swappiness = swappiness,
+ .order = 0,
+ .mem_cgroup = mem,
+ .isolate_pages = mem_cgroup_isolate_pages,
+ };
+ 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;
+ /*
+ * NOTE: Although we can get the priority field, using it
+ * here is not a good idea, since it limits the pages we can scan.
+ * if we don't reclaim here, the shrink_zone from balance_pgdat
+ * will pick up pages from other mem cgroup's as well. We hack
+ * the priority and make it zero.
+ */
+ shrink_zone(0, zone, &sc);
+ return sc.nr_reclaimed;
+}
+
unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
gfp_t gfp_mask,
bool noswap,
unsigned int swappiness)
{
+ struct zonelist *zonelist;
struct scan_control sc = {
.may_writepage = !laptop_mode,
.may_unmap = 1,
.may_swap = !noswap,
- .swap_cluster_max = SWAP_CLUSTER_MAX,
+ .nr_to_reclaim = 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;
sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
}
#endif
+/* is kswapd sleeping prematurely? */
+static int sleeping_prematurely(pg_data_t *pgdat, int order, long remaining)
+{
+ int i;
+
+ /* If a direct reclaimer woke kswapd within HZ/10, it's premature */
+ if (remaining)
+ return 1;
+
+ /* If after HZ/10, a zone is below the high mark, it's premature */
+ for (i = 0; i < pgdat->nr_zones; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ if (!populated_zone(zone))
+ continue;
+
+ if (zone_is_all_unreclaimable(zone))
+ continue;
+
+ if (!zone_watermark_ok(zone, order, high_wmark_pages(zone),
+ 0, 0))
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* For kswapd, balance_pgdat() will work across all this node's zones until
* they are all at high_wmark_pages(zone).
.gfp_mask = GFP_KERNEL,
.may_unmap = 1,
.may_swap = 1,
- .swap_cluster_max = SWAP_CLUSTER_MAX,
+ /*
+ * kswapd doesn't want to be bailed out while reclaim. because
+ * we want to put equal scanning pressure on each zone.
+ */
+ .nr_to_reclaim = ULONG_MAX,
.swappiness = vm_swappiness,
.order = order,
.mem_cgroup = NULL,
for (priority = DEF_PRIORITY; priority >= 0; priority--) {
int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
unsigned long lru_pages = 0;
+ int has_under_min_watermark_zone = 0;
/* The swap token gets in the way of swapout... */
if (!priority)
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
- lru_pages += zone_lru_pages(zone);
+ lru_pages += zone_reclaimable_pages(zone);
}
/*
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;
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);
/*
* We put equal pressure on every zone, unless one
* zone has way too many pages free already.
if (zone_is_all_unreclaimable(zone))
continue;
if (nr_slab == 0 && zone->pages_scanned >=
- (zone_lru_pages(zone) * 6))
+ (zone_reclaimable_pages(zone) * 6))
zone_set_flag(zone,
ZONE_ALL_UNRECLAIMABLE);
/*
if (total_scanned > SWAP_CLUSTER_MAX * 2 &&
total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
sc.may_writepage = 1;
+
+ /*
+ * We are still under min water mark. it mean we have
+ * GFP_ATOMIC allocation failure risk. Hurry up!
+ */
+ if (!zone_watermark_ok(zone, order, min_wmark_pages(zone),
+ end_zone, 0))
+ has_under_min_watermark_zone = 1;
+
}
if (all_zones_ok)
break; /* kswapd: all done */
* OK, kswapd is getting into trouble. Take a nap, then take
* another pass across the zones.
*/
- if (total_scanned && priority < DEF_PRIORITY - 2)
- congestion_wait(WRITE, HZ/10);
+ if (total_scanned && (priority < DEF_PRIORITY - 2)) {
+ if (has_under_min_watermark_zone)
+ count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT);
+ else
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ }
/*
* We do this so kswapd doesn't build up large priorities for
order = 0;
for ( ; ; ) {
unsigned long new_order;
+ int ret;
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
new_order = pgdat->kswapd_max_order;
*/
order = new_order;
} else {
- if (!freezing(current))
- schedule();
+ if (!freezing(current) && !kthread_should_stop()) {
+ long remaining = 0;
+
+ /* Try to sleep for a short interval */
+ if (!sleeping_prematurely(pgdat, order, remaining)) {
+ remaining = schedule_timeout(HZ/10);
+ finish_wait(&pgdat->kswapd_wait, &wait);
+ prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
+ }
+
+ /*
+ * After a short sleep, check if it was a
+ * premature sleep. If not, then go fully
+ * to sleep until explicitly woken up
+ */
+ if (!sleeping_prematurely(pgdat, order, remaining))
+ schedule();
+ else {
+ if (remaining)
+ count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY);
+ else
+ count_vm_event(KSWAPD_HIGH_WMARK_HIT_QUICKLY);
+ }
+ }
order = pgdat->kswapd_max_order;
}
finish_wait(&pgdat->kswapd_wait, &wait);
- if (!try_to_freeze()) {
- /* We can speed up thawing tasks if we don't call
- * balance_pgdat after returning from the refrigerator
- */
+ ret = try_to_freeze();
+ if (kthread_should_stop())
+ break;
+
+ /*
+ * We can speed up thawing tasks if we don't call balance_pgdat
+ * after returning from the refrigerator
+ */
+ if (!ret)
balance_pgdat(pgdat, order);
- }
}
return 0;
}
wake_up_interruptible(&pgdat->kswapd_wait);
}
-unsigned long global_lru_pages(void)
-{
- return global_page_state(NR_ACTIVE_ANON)
- + global_page_state(NR_ACTIVE_FILE)
- + global_page_state(NR_INACTIVE_ANON)
- + global_page_state(NR_INACTIVE_FILE);
-}
-
-#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.
- *
- * For pass > 3 we also try to shrink the LRU lists that contain a few pages
+ * The reclaimable count would be mostly accurate.
+ * The less reclaimable pages may be
+ * - mlocked pages, which will be moved to unevictable list when encountered
+ * - mapped pages, which may require several travels to be reclaimed
+ * - dirty pages, which is not "instantly" reclaimable
*/
-static void shrink_all_zones(unsigned long nr_pages, int prio,
- int pass, struct scan_control *sc)
+unsigned long global_reclaimable_pages(void)
{
- struct zone *zone;
- unsigned long nr_reclaimed = 0;
+ int nr;
- for_each_populated_zone(zone) {
- enum lru_list l;
+ nr = global_page_state(NR_ACTIVE_FILE) +
+ global_page_state(NR_INACTIVE_FILE);
- if (zone_is_all_unreclaimable(zone) && prio != DEF_PRIORITY)
- continue;
+ if (nr_swap_pages > 0)
+ nr += global_page_state(NR_ACTIVE_ANON) +
+ global_page_state(NR_INACTIVE_ANON);
- for_each_evictable_lru(l) {
- enum zone_stat_item ls = NR_LRU_BASE + l;
- unsigned long lru_pages = zone_page_state(zone, ls);
+ return nr;
+}
- /* For pass = 0, we don't shrink the active list */
- if (pass == 0 && (l == LRU_ACTIVE_ANON ||
- l == LRU_ACTIVE_FILE))
- continue;
+unsigned long zone_reclaimable_pages(struct zone *zone)
+{
+ int nr;
- 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 (nr_reclaimed >= nr_pages) {
- sc->nr_reclaimed += nr_reclaimed;
- return;
- }
- }
- }
- }
- sc->nr_reclaimed += nr_reclaimed;
+ nr = zone_page_state(zone, NR_ACTIVE_FILE) +
+ zone_page_state(zone, NR_INACTIVE_FILE);
+
+ if (nr_swap_pages > 0)
+ nr += zone_page_state(zone, NR_ACTIVE_ANON) +
+ zone_page_state(zone, NR_INACTIVE_ANON);
+
+ return nr;
}
+#ifdef CONFIG_HIBERNATION
/*
- * Try to free `nr_pages' of memory, system-wide, and return the number of
+ * Try to free `nr_to_reclaim' of memory, system-wide, and return the number of
* freed pages.
*
* Rather than trying to age LRUs the aim is to preserve the overall
* LRU order by reclaiming preferentially
* inactive > active > active referenced > active mapped
*/
-unsigned long shrink_all_memory(unsigned long nr_pages)
+unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
{
- unsigned long lru_pages, nr_slab;
- int pass;
struct reclaim_state reclaim_state;
struct scan_control sc = {
- .gfp_mask = GFP_KERNEL,
- .may_unmap = 0,
+ .gfp_mask = GFP_HIGHUSER_MOVABLE,
+ .may_swap = 1,
+ .may_unmap = 1,
.may_writepage = 1,
+ .nr_to_reclaim = nr_to_reclaim,
+ .hibernation_mode = 1,
+ .swappiness = vm_swappiness,
+ .order = 0,
.isolate_pages = isolate_pages_global,
- .nr_reclaimed = 0,
};
+ struct zonelist * zonelist = node_zonelist(numa_node_id(), sc.gfp_mask);
+ struct task_struct *p = current;
+ unsigned long nr_reclaimed;
- current->reclaim_state = &reclaim_state;
-
- lru_pages = global_lru_pages();
- nr_slab = global_page_state(NR_SLAB_RECLAIMABLE);
- /* If slab caches are huge, it's better to hit them first */
- while (nr_slab >= lru_pages) {
- reclaim_state.reclaimed_slab = 0;
- shrink_slab(nr_pages, sc.gfp_mask, lru_pages);
- if (!reclaim_state.reclaimed_slab)
- break;
-
- sc.nr_reclaimed += reclaim_state.reclaimed_slab;
- if (sc.nr_reclaimed >= nr_pages)
- goto out;
-
- nr_slab -= reclaim_state.reclaimed_slab;
- }
-
- /*
- * We try to shrink LRUs in 5 passes:
- * 0 = Reclaim from inactive_list only
- * 1 = Reclaim from active list but don't reclaim mapped
- * 2 = 2nd pass of type 1
- * 3 = Reclaim mapped (normal reclaim)
- * 4 = 2nd pass of type 3
- */
- for (pass = 0; pass < 5; pass++) {
- int prio;
-
- /* Force reclaiming mapped pages in the passes #3 and #4 */
- if (pass > 2)
- sc.may_unmap = 1;
-
- for (prio = DEF_PRIORITY; prio >= 0; prio--) {
- unsigned long nr_to_scan = nr_pages - sc.nr_reclaimed;
-
- sc.nr_scanned = 0;
- 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());
- 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);
- }
- }
-
- /*
- * If sc.nr_reclaimed = 0, we could not shrink LRUs, but there may be
- * something in slab caches
- */
- if (!sc.nr_reclaimed) {
- do {
- reclaim_state.reclaimed_slab = 0;
- shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
- sc.nr_reclaimed += reclaim_state.reclaimed_slab;
- } while (sc.nr_reclaimed < nr_pages &&
- reclaim_state.reclaimed_slab > 0);
- }
+ p->flags |= PF_MEMALLOC;
+ lockdep_set_current_reclaim_state(sc.gfp_mask);
+ reclaim_state.reclaimed_slab = 0;
+ p->reclaim_state = &reclaim_state;
+ nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
-out:
- current->reclaim_state = NULL;
+ p->reclaim_state = NULL;
+ lockdep_clear_current_reclaim_state();
+ p->flags &= ~PF_MEMALLOC;
- return sc.nr_reclaimed;
+ return nr_reclaimed;
}
#endif /* CONFIG_HIBERNATION */
return ret;
}
+/*
+ * Called by memory hotplug when all memory in a node is offlined.
+ */
+void kswapd_stop(int nid)
+{
+ struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
+
+ if (kswapd)
+ kthread_stop(kswapd);
+}
+
static int __init kswapd_init(void)
{
int nid;
.may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
.may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP),
.may_swap = 1,
- .swap_cluster_max = max_t(unsigned long, nr_pages,
- SWAP_CLUSTER_MAX),
+ .nr_to_reclaim = max_t(unsigned long, nr_pages,
+ SWAP_CLUSTER_MAX),
.gfp_mask = gfp_mask,
.swappiness = vm_swappiness,
.order = order,
retry:
ClearPageUnevictable(page);
if (page_evictable(page, NULL)) {
- enum lru_list l = LRU_INACTIVE_ANON + page_is_file_cache(page);
+ enum lru_list l = page_lru_base_type(page);
__dec_zone_state(zone, NR_UNEVICTABLE);
list_move(&page->lru, &zone->lru[l].list);
unsigned long scan_unevictable_pages;
int scan_unevictable_handler(struct ctl_table *table, int write,
- struct file *file, void __user *buffer,
+ void __user *buffer,
size_t *length, loff_t *ppos)
{
- proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+ proc_doulongvec_minmax(table, write, buffer, length, ppos);
if (write && *(unsigned long *)table->data)
scan_all_zones_unevictable_pages();
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff