diff options
| author | Vinayak Menon <vinmenon@codeaurora.org> | 2015-01-17 21:51:48 +0530 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-22 11:03:54 -0700 |
| commit | d487a9f1f7291870ebeac3bc243f9fe65dcdfefb (patch) | |
| tree | 3ae7492534ee2e17b44990a271f3d5d85f2b99eb /mm/compaction.c | |
| parent | 910a8bd10838baff2a8894a4e8686a9d3eba5a35 (diff) | |
mm: compaction: fix the page state calculation in too_many_isolated
Commit "mm: vmscan: fix the page state calculation in too_many_isolated"
fixed an issue where a number of tasks were blocked in reclaim path
for seconds, because of vmstat_diff not being synced in time.
A similar problem can happen in isolate_migratepages_block, where
similar calculation is performed. This patch fixes that.
Change-Id: Ie74f108ef770da688017b515fe37faea6f384589
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Diffstat (limited to 'mm/compaction.c')
| -rw-r--r-- | mm/compaction.c | 43 |
1 files changed, 34 insertions, 9 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index ad6ee6da933d..e0d4a58bcee4 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -627,21 +627,46 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc) mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]); } -/* Similar to reclaim, but different enough that they don't share logic */ -static bool too_many_isolated(struct zone *zone) +static bool __too_many_isolated(struct zone *zone, int safe) { unsigned long active, inactive, isolated; - inactive = zone_page_state(zone, NR_INACTIVE_FILE) + - zone_page_state(zone, NR_INACTIVE_ANON); - active = zone_page_state(zone, NR_ACTIVE_FILE) + - zone_page_state(zone, NR_ACTIVE_ANON); - isolated = zone_page_state(zone, NR_ISOLATED_FILE) + - zone_page_state(zone, NR_ISOLATED_ANON); + if (safe) { + inactive = zone_page_state_snapshot(zone, NR_INACTIVE_FILE) + + zone_page_state_snapshot(zone, NR_INACTIVE_ANON); + active = zone_page_state_snapshot(zone, NR_ACTIVE_FILE) + + zone_page_state_snapshot(zone, NR_ACTIVE_ANON); + isolated = zone_page_state_snapshot(zone, NR_ISOLATED_FILE) + + zone_page_state_snapshot(zone, NR_ISOLATED_ANON); + } else { + inactive = zone_page_state(zone, NR_INACTIVE_FILE) + + zone_page_state(zone, NR_INACTIVE_ANON); + active = zone_page_state(zone, NR_ACTIVE_FILE) + + zone_page_state(zone, NR_ACTIVE_ANON); + isolated = zone_page_state(zone, NR_ISOLATED_FILE) + + zone_page_state(zone, NR_ISOLATED_ANON); + } return isolated > (inactive + active) / 2; } +/* Similar to reclaim, but different enough that they don't share logic */ +static bool too_many_isolated(struct compact_control *cc) +{ + /* + * __too_many_isolated(safe=0) is fast but inaccurate, because it + * doesn't account for the vm_stat_diff[] counters. So if it looks + * like too_many_isolated() is about to return true, fall back to the + * slower, more accurate zone_page_state_snapshot(). + */ + if (unlikely(__too_many_isolated(cc->zone, 0))) { + if (cc->mode != MIGRATE_ASYNC) + return __too_many_isolated(cc->zone, 1); + } + + return false; +} + /** * isolate_migratepages_block() - isolate all migrate-able pages within * a single pageblock @@ -678,7 +703,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, * list by either parallel reclaimers or compaction. If there are, * delay for some time until fewer pages are isolated */ - while (unlikely(too_many_isolated(zone))) { + while (unlikely(too_many_isolated(cc))) { /* async migration should just abort */ if (cc->mode == MIGRATE_ASYNC) return 0; |