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-rw-r--r--include/linux/vmstat.h3
-rw-r--r--mm/vmscan.c38
-rw-r--r--mm/vmstat.c5
3 files changed, 34 insertions, 12 deletions
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index fd5be240c0b7..ee03bba9c5df 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -40,7 +40,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
PGSCAN_ZONE_RECLAIM_FAILED,
#endif
PGINODESTEAL, SLABS_SCANNED, KSWAPD_STEAL, KSWAPD_INODESTEAL,
- KSWAPD_PREMATURE_FAST, KSWAPD_PREMATURE_SLOW,
+ KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY,
+ KSWAPD_SKIP_CONGESTION_WAIT,
PAGEOUTRUN, ALLOCSTALL, PGROTATED,
#ifdef CONFIG_HUGETLB_PAGE
HTLB_BUDDY_PGALLOC, HTLB_BUDDY_PGALLOC_FAIL,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index e176bd3936da..cb69f717799f 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1905,19 +1905,25 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
#endif
/* is kswapd sleeping prematurely? */
-static int sleeping_prematurely(int order, long remaining)
+static int sleeping_prematurely(pg_data_t *pgdat, int order, long remaining)
{
- struct zone *zone;
+ 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_each_populated_zone(zone)
+ for (i = 0; i < pgdat->nr_zones; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ if (!populated_zone(zone))
+ continue;
+
if (!zone_watermark_ok(zone, order, high_wmark_pages(zone),
0, 0))
return 1;
+ }
return 0;
}
@@ -1979,6 +1985,7 @@ loop_again:
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)
@@ -2085,6 +2092,15 @@ loop_again:
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 */
@@ -2092,8 +2108,12 @@ loop_again:
* 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(BLK_RW_ASYNC, 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
@@ -2207,7 +2227,7 @@ static int kswapd(void *p)
long remaining = 0;
/* Try to sleep for a short interval */
- if (!sleeping_prematurely(order, remaining)) {
+ 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);
@@ -2218,13 +2238,13 @@ static int kswapd(void *p)
* premature sleep. If not, then go fully
* to sleep until explicitly woken up
*/
- if (!sleeping_prematurely(order, remaining))
+ if (!sleeping_prematurely(pgdat, order, remaining))
schedule();
else {
if (remaining)
- count_vm_event(KSWAPD_PREMATURE_FAST);
+ count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY);
else
- count_vm_event(KSWAPD_PREMATURE_SLOW);
+ count_vm_event(KSWAPD_HIGH_WMARK_HIT_QUICKLY);
}
}
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 63ab71455c5b..6051fbab67ba 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -683,8 +683,9 @@ static const char * const vmstat_text[] = {
"slabs_scanned",
"kswapd_steal",
"kswapd_inodesteal",
- "kswapd_slept_prematurely_fast",
- "kswapd_slept_prematurely_slow",
+ "kswapd_low_wmark_hit_quickly",
+ "kswapd_high_wmark_hit_quickly",
+ "kswapd_skip_congestion_wait",
"pageoutrun",
"allocstall",