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Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c232
1 files changed, 86 insertions, 146 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0da572753..87cbf6cd6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -195,25 +195,25 @@ static unsigned long zone_reclaimable_pages(struct zone *zone)
{
unsigned long nr;
- nr = zone_page_state(zone, NR_ACTIVE_FILE) +
- zone_page_state(zone, NR_INACTIVE_FILE) +
- zone_page_state(zone, NR_ISOLATED_FILE);
+ nr = zone_page_state_snapshot(zone, NR_ACTIVE_FILE) +
+ zone_page_state_snapshot(zone, NR_INACTIVE_FILE) +
+ zone_page_state_snapshot(zone, NR_ISOLATED_FILE);
if (get_nr_swap_pages() > 0)
- nr += zone_page_state(zone, NR_ACTIVE_ANON) +
- zone_page_state(zone, NR_INACTIVE_ANON) +
- zone_page_state(zone, NR_ISOLATED_ANON);
+ nr += zone_page_state_snapshot(zone, NR_ACTIVE_ANON) +
+ zone_page_state_snapshot(zone, NR_INACTIVE_ANON) +
+ zone_page_state_snapshot(zone, NR_ISOLATED_ANON);
return nr;
}
bool zone_reclaimable(struct zone *zone)
{
- return zone_page_state(zone, NR_PAGES_SCANNED) <
+ return zone_page_state_snapshot(zone, NR_PAGES_SCANNED) <
zone_reclaimable_pages(zone) * 6;
}
-static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru)
+unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru)
{
if (!mem_cgroup_disabled())
return mem_cgroup_get_lru_size(lruvec, lru);
@@ -228,14 +228,6 @@ int register_shrinker(struct shrinker *shrinker)
{
size_t size = sizeof(*shrinker->nr_deferred);
- /*
- * If we only have one possible node in the system anyway, save
- * ourselves the trouble and disable NUMA aware behavior. This way we
- * will save memory and some small loop time later.
- */
- if (nr_node_ids == 1)
- shrinker->flags &= ~SHRINKER_NUMA_AWARE;
-
if (shrinker->flags & SHRINKER_NUMA_AWARE)
size *= nr_node_ids;
@@ -390,9 +382,8 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
*
* @memcg specifies the memory cgroup to target. If it is not NULL,
* only shrinkers with SHRINKER_MEMCG_AWARE set will be called to scan
- * objects from the memory cgroup specified. Otherwise all shrinkers
- * are called, and memcg aware shrinkers are supposed to scan the
- * global list then.
+ * objects from the memory cgroup specified. Otherwise, only unaware
+ * shrinkers are called.
*
* @nr_scanned and @nr_eligible form a ratio that indicate how much of
* the available objects should be scanned. Page reclaim for example
@@ -412,7 +403,7 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
struct shrinker *shrinker;
unsigned long freed = 0;
- if (memcg && !memcg_kmem_online(memcg))
+ if (memcg && (!memcg_kmem_enabled() || !mem_cgroup_online(memcg)))
return 0;
if (nr_scanned == 0)
@@ -436,7 +427,13 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
.memcg = memcg,
};
- if (memcg && !(shrinker->flags & SHRINKER_MEMCG_AWARE))
+ /*
+ * If kernel memory accounting is disabled, we ignore
+ * SHRINKER_MEMCG_AWARE flag and call all shrinkers
+ * passing NULL for memcg.
+ */
+ if (memcg_kmem_enabled() &&
+ !!memcg != !!(shrinker->flags & SHRINKER_MEMCG_AWARE))
continue;
if (!(shrinker->flags & SHRINKER_NUMA_AWARE))
@@ -611,12 +608,10 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
bool reclaimed)
{
unsigned long flags;
- struct mem_cgroup *memcg;
BUG_ON(!PageLocked(page));
BUG_ON(mapping != page_mapping(page));
- memcg = mem_cgroup_begin_page_stat(page);
spin_lock_irqsave(&mapping->tree_lock, flags);
/*
* The non racy check for a busy page.
@@ -643,11 +638,11 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
* Note that if SetPageDirty is always performed via set_page_dirty,
* and thus under tree_lock, then this ordering is not required.
*/
- if (!page_freeze_refs(page, 2))
+ if (!page_ref_freeze(page, 2))
goto cannot_free;
/* note: atomic_cmpxchg in page_freeze_refs provides the smp_rmb */
if (unlikely(PageDirty(page))) {
- page_unfreeze_refs(page, 2);
+ page_ref_unfreeze(page, 2);
goto cannot_free;
}
@@ -656,7 +651,6 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
mem_cgroup_swapout(page, swap);
__delete_from_swap_cache(page);
spin_unlock_irqrestore(&mapping->tree_lock, flags);
- mem_cgroup_end_page_stat(memcg);
swapcache_free(swap);
} else {
void (*freepage)(struct page *);
@@ -682,9 +676,8 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
if (reclaimed && page_is_file_cache(page) &&
!mapping_exiting(mapping) && !dax_mapping(mapping))
shadow = workingset_eviction(mapping, page);
- __delete_from_page_cache(page, shadow, memcg);
+ __delete_from_page_cache(page, shadow);
spin_unlock_irqrestore(&mapping->tree_lock, flags);
- mem_cgroup_end_page_stat(memcg);
if (freepage != NULL)
freepage(page);
@@ -694,7 +687,6 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
cannot_free:
spin_unlock_irqrestore(&mapping->tree_lock, flags);
- mem_cgroup_end_page_stat(memcg);
return 0;
}
@@ -712,7 +704,7 @@ int remove_mapping(struct address_space *mapping, struct page *page)
* drops the pagecache ref for us without requiring another
* atomic operation.
*/
- page_unfreeze_refs(page, 1);
+ page_ref_unfreeze(page, 1);
return 1;
}
return 0;
@@ -1931,8 +1923,8 @@ static bool inactive_file_is_low(struct lruvec *lruvec)
unsigned long inactive;
unsigned long active;
- inactive = get_lru_size(lruvec, LRU_INACTIVE_FILE);
- active = get_lru_size(lruvec, LRU_ACTIVE_FILE);
+ inactive = lruvec_lru_size(lruvec, LRU_INACTIVE_FILE);
+ active = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE);
return active > inactive;
}
@@ -2071,7 +2063,7 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg,
* system is under heavy pressure.
*/
if (!inactive_file_is_low(lruvec) &&
- get_lru_size(lruvec, LRU_INACTIVE_FILE) >> sc->priority) {
+ lruvec_lru_size(lruvec, LRU_INACTIVE_FILE) >> sc->priority) {
scan_balance = SCAN_FILE;
goto out;
}
@@ -2097,10 +2089,10 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg,
* anon in [0], file in [1]
*/
- anon = get_lru_size(lruvec, LRU_ACTIVE_ANON) +
- get_lru_size(lruvec, LRU_INACTIVE_ANON);
- file = get_lru_size(lruvec, LRU_ACTIVE_FILE) +
- get_lru_size(lruvec, LRU_INACTIVE_FILE);
+ anon = lruvec_lru_size(lruvec, LRU_ACTIVE_ANON) +
+ lruvec_lru_size(lruvec, LRU_INACTIVE_ANON);
+ file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE) +
+ lruvec_lru_size(lruvec, LRU_INACTIVE_FILE);
spin_lock_irq(&zone->lru_lock);
if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
@@ -2138,7 +2130,7 @@ out:
unsigned long size;
unsigned long scan;
- size = get_lru_size(lruvec, lru);
+ size = lruvec_lru_size(lruvec, lru);
scan = size >> sc->priority;
if (!scan && pass && force_scan)
@@ -2990,18 +2982,23 @@ static void age_active_anon(struct zone *zone, struct scan_control *sc)
} while (memcg);
}
-static bool zone_balanced(struct zone *zone, int order,
- unsigned long balance_gap, int classzone_idx)
+static bool zone_balanced(struct zone *zone, int order, bool highorder,
+ unsigned long balance_gap, int classzone_idx)
{
- if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone) +
- balance_gap, classzone_idx))
- return false;
+ unsigned long mark = high_wmark_pages(zone) + balance_gap;
- if (IS_ENABLED(CONFIG_COMPACTION) && order && compaction_suitable(zone,
- order, 0, classzone_idx) == COMPACT_SKIPPED)
- return false;
+ /*
+ * When checking from pgdat_balanced(), kswapd should stop and sleep
+ * when it reaches the high order-0 watermark and let kcompactd take
+ * over. Other callers such as wakeup_kswapd() want to determine the
+ * true high-order watermark.
+ */
+ if (IS_ENABLED(CONFIG_COMPACTION) && !highorder) {
+ mark += (1UL << order);
+ order = 0;
+ }
- return true;
+ return zone_watermark_ok_safe(zone, order, mark, classzone_idx);
}
/*
@@ -3051,7 +3048,7 @@ static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx)
continue;
}
- if (zone_balanced(zone, order, 0, i))
+ if (zone_balanced(zone, order, false, 0, i))
balanced_pages += zone->managed_pages;
else if (!order)
return false;
@@ -3105,10 +3102,8 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
*/
static bool kswapd_shrink_zone(struct zone *zone,
int classzone_idx,
- struct scan_control *sc,
- unsigned long *nr_attempted)
+ struct scan_control *sc)
{
- int testorder = sc->order;
unsigned long balance_gap;
bool lowmem_pressure;
@@ -3116,17 +3111,6 @@ static bool kswapd_shrink_zone(struct zone *zone,
sc->nr_to_reclaim = max(SWAP_CLUSTER_MAX, high_wmark_pages(zone));
/*
- * Kswapd reclaims only single pages with compaction enabled. Trying
- * too hard to reclaim until contiguous free pages have become
- * available can hurt performance by evicting too much useful data
- * from memory. Do not reclaim more than needed for compaction.
- */
- if (IS_ENABLED(CONFIG_COMPACTION) && sc->order &&
- compaction_suitable(zone, sc->order, 0, classzone_idx)
- != COMPACT_SKIPPED)
- testorder = 0;
-
- /*
* We put equal pressure on every zone, unless one zone has way too
* many pages free already. The "too many pages" is defined as the
* high wmark plus a "gap" where the gap is either the low
@@ -3140,15 +3124,12 @@ static bool kswapd_shrink_zone(struct zone *zone,
* reclaim is necessary
*/
lowmem_pressure = (buffer_heads_over_limit && is_highmem(zone));
- if (!lowmem_pressure && zone_balanced(zone, testorder,
+ if (!lowmem_pressure && zone_balanced(zone, sc->order, false,
balance_gap, classzone_idx))
return true;
shrink_zone(zone, sc, zone_idx(zone) == classzone_idx);
- /* Account for the number of pages attempted to reclaim */
- *nr_attempted += sc->nr_to_reclaim;
-
clear_bit(ZONE_WRITEBACK, &zone->flags);
/*
@@ -3158,7 +3139,7 @@ static bool kswapd_shrink_zone(struct zone *zone,
* waits.
*/
if (zone_reclaimable(zone) &&
- zone_balanced(zone, testorder, 0, classzone_idx)) {
+ zone_balanced(zone, sc->order, false, 0, classzone_idx)) {
clear_bit(ZONE_CONGESTED, &zone->flags);
clear_bit(ZONE_DIRTY, &zone->flags);
}
@@ -3170,7 +3151,7 @@ static bool kswapd_shrink_zone(struct zone *zone,
* For kswapd, balance_pgdat() will work across all this node's zones until
* they are all at high_wmark_pages(zone).
*
- * Returns the final order kswapd was reclaiming at
+ * Returns the highest zone idx kswapd was reclaiming at
*
* There is special handling here for zones which are full of pinned pages.
* This can happen if the pages are all mlocked, or if they are all used by
@@ -3187,8 +3168,7 @@ static bool kswapd_shrink_zone(struct zone *zone,
* 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,
- int *classzone_idx)
+static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
{
int i;
int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
@@ -3205,9 +3185,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
count_vm_event(PAGEOUTRUN);
do {
- unsigned long nr_attempted = 0;
bool raise_priority = true;
- bool pgdat_needs_compaction = (order > 0);
sc.nr_reclaimed = 0;
@@ -3242,7 +3220,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
break;
}
- if (!zone_balanced(zone, order, 0, 0)) {
+ if (!zone_balanced(zone, order, false, 0, 0)) {
end_zone = i;
break;
} else {
@@ -3258,24 +3236,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
if (i < 0)
goto out;
- for (i = 0; i <= end_zone; i++) {
- struct zone *zone = pgdat->node_zones + i;
-
- if (!populated_zone(zone))
- continue;
-
- /*
- * If any zone is currently balanced then kswapd will
- * not call compaction as it is expected that the
- * necessary pages are already available.
- */
- if (pgdat_needs_compaction &&
- zone_watermark_ok(zone, order,
- low_wmark_pages(zone),
- *classzone_idx, 0))
- pgdat_needs_compaction = false;
- }
-
/*
* If we're getting trouble reclaiming, start doing writepage
* even in laptop mode.
@@ -3319,8 +3279,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
* that that high watermark would be met at 100%
* efficiency.
*/
- if (kswapd_shrink_zone(zone, end_zone,
- &sc, &nr_attempted))
+ if (kswapd_shrink_zone(zone, end_zone, &sc))
raise_priority = false;
}
@@ -3333,49 +3292,29 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
pfmemalloc_watermark_ok(pgdat))
wake_up_all(&pgdat->pfmemalloc_wait);
- /*
- * Fragmentation may mean that the system cannot be rebalanced
- * for high-order allocations in all zones. If twice the
- * allocation size has been reclaimed and the zones are still
- * not balanced then recheck the watermarks at order-0 to
- * prevent kswapd reclaiming excessively. Assume that a
- * process requested a high-order can direct reclaim/compact.
- */
- if (order && sc.nr_reclaimed >= 2UL << order)
- order = sc.order = 0;
-
/* Check if kswapd should be suspending */
if (try_to_freeze() || kthread_should_stop())
break;
/*
- * Compact if necessary and kswapd is reclaiming at least the
- * high watermark number of pages as requsted
- */
- if (pgdat_needs_compaction && sc.nr_reclaimed > nr_attempted)
- compact_pgdat(pgdat, order);
-
- /*
* Raise priority if scanning rate is too low or there was no
* progress in reclaiming pages
*/
if (raise_priority || !sc.nr_reclaimed)
sc.priority--;
} while (sc.priority >= 1 &&
- !pgdat_balanced(pgdat, order, *classzone_idx));
+ !pgdat_balanced(pgdat, order, classzone_idx));
out:
/*
- * Return the order we were reclaiming at so prepare_kswapd_sleep()
- * makes a decision on the order we were last reclaiming at. However,
- * if another caller entered the allocator slow path while kswapd
- * was awake, order will remain at the higher level
+ * Return the highest zone idx we were reclaiming at so
+ * prepare_kswapd_sleep() makes the same decisions as here.
*/
- *classzone_idx = end_zone;
- return order;
+ return end_zone;
}
-static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
+static void kswapd_try_to_sleep(pg_data_t *pgdat, int order,
+ int classzone_idx, int balanced_classzone_idx)
{
long remaining = 0;
DEFINE_WAIT(wait);
@@ -3386,7 +3325,22 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
/* Try to sleep for a short interval */
- if (prepare_kswapd_sleep(pgdat, order, remaining, classzone_idx)) {
+ if (prepare_kswapd_sleep(pgdat, order, remaining,
+ balanced_classzone_idx)) {
+ /*
+ * Compaction records what page blocks it recently failed to
+ * isolate pages from and skips them in the future scanning.
+ * When kswapd is going to sleep, it is reasonable to assume
+ * that pages and compaction may succeed so reset the cache.
+ */
+ reset_isolation_suitable(pgdat);
+
+ /*
+ * We have freed the memory, now we should compact it to make
+ * allocation of the requested order possible.
+ */
+ wakeup_kcompactd(pgdat, order, classzone_idx);
+
remaining = schedule_timeout(HZ/10);
finish_wait(&pgdat->kswapd_wait, &wait);
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
@@ -3396,7 +3350,8 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
* After a short sleep, check if it was a premature sleep. If not, then
* go fully to sleep until explicitly woken up.
*/
- if (prepare_kswapd_sleep(pgdat, order, remaining, classzone_idx)) {
+ if (prepare_kswapd_sleep(pgdat, order, remaining,
+ balanced_classzone_idx)) {
trace_mm_vmscan_kswapd_sleep(pgdat->node_id);
/*
@@ -3409,14 +3364,6 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
*/
set_pgdat_percpu_threshold(pgdat, calculate_normal_threshold);
- /*
- * Compaction records what page blocks it recently failed to
- * isolate pages from and skips them in the future scanning.
- * When kswapd is going to sleep, it is reasonable to assume
- * that pages and compaction may succeed so reset the cache.
- */
- reset_isolation_suitable(pgdat);
-
if (!kthread_should_stop())
schedule();
@@ -3446,7 +3393,6 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
static int kswapd(void *p)
{
unsigned long order, new_order;
- unsigned balanced_order;
int classzone_idx, new_classzone_idx;
int balanced_classzone_idx;
pg_data_t *pgdat = (pg_data_t*)p;
@@ -3479,24 +3425,19 @@ static int kswapd(void *p)
set_freezable();
order = new_order = 0;
- balanced_order = 0;
classzone_idx = new_classzone_idx = pgdat->nr_zones - 1;
balanced_classzone_idx = classzone_idx;
for ( ; ; ) {
bool ret;
/*
- * If the last balance_pgdat was unsuccessful it's unlikely a
- * new request of a similar or harder type will succeed soon
- * so consider going to sleep on the basis we reclaimed at
+ * While we were reclaiming, there might have been another
+ * wakeup, so check the values.
*/
- if (balanced_classzone_idx >= new_classzone_idx &&
- balanced_order == new_order) {
- new_order = pgdat->kswapd_max_order;
- new_classzone_idx = pgdat->classzone_idx;
- pgdat->kswapd_max_order = 0;
- pgdat->classzone_idx = pgdat->nr_zones - 1;
- }
+ new_order = pgdat->kswapd_max_order;
+ new_classzone_idx = pgdat->classzone_idx;
+ pgdat->kswapd_max_order = 0;
+ pgdat->classzone_idx = pgdat->nr_zones - 1;
if (order < new_order || classzone_idx > new_classzone_idx) {
/*
@@ -3506,7 +3447,7 @@ static int kswapd(void *p)
order = new_order;
classzone_idx = new_classzone_idx;
} else {
- kswapd_try_to_sleep(pgdat, balanced_order,
+ kswapd_try_to_sleep(pgdat, order, classzone_idx,
balanced_classzone_idx);
order = pgdat->kswapd_max_order;
classzone_idx = pgdat->classzone_idx;
@@ -3526,9 +3467,8 @@ static int kswapd(void *p)
*/
if (!ret) {
trace_mm_vmscan_kswapd_wake(pgdat->node_id, order);
- balanced_classzone_idx = classzone_idx;
- balanced_order = balance_pgdat(pgdat, order,
- &balanced_classzone_idx);
+ balanced_classzone_idx = balance_pgdat(pgdat, order,
+ classzone_idx);
}
}
@@ -3563,7 +3503,7 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx)
}
if (!waitqueue_active(&pgdat->kswapd_wait))
return;
- if (zone_balanced(zone, order, 0, 0))
+ if (zone_balanced(zone, order, true, 0, 0))
return;
trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order);