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author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2010-04-06 14:34:56 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-04-07 08:38:03 -0700 |
commit | d6da1a5abc2bf3a06a5bda08e0f6833409234666 (patch) | |
tree | dd6e7a306879b49a7947d3f7015bc84f5e27d869 | |
parent | 6e191f7bb083544dc4fa3879ff81caf97c65d197 (diff) | |
download | linux-stable-d6da1a5abc2bf3a06a5bda08e0f6833409234666.tar.gz linux-stable-d6da1a5abc2bf3a06a5bda08e0f6833409234666.tar.bz2 linux-stable-d6da1a5abc2bf3a06a5bda08e0f6833409234666.zip |
mm: revert "vmscan: get_scan_ratio() cleanup"
Shaohua Li reported his tmpfs streaming I/O test can lead to make oom.
The test uses a 6G tmpfs in a system with 3G memory. In the tmpfs, there
are 6 copies of kernel source and the test does kbuild for each copy. His
investigation shows the test has a lot of rotated anon pages and quite few
file pages, so get_scan_ratio calculates percent[0] (i.e. scanning
percent for anon) to be zero. Actually the percent[0] shoule be a big
value, but our calculation round it to zero.
Although before commit 84b18490 ("vmscan: get_scan_ratio() cleanup") , we
have the same problem too. But the old logic can rescue percent[0]==0
case only when priority==0. It had hided the real issue. I didn't think
merely streaming io can makes percent[0]==0 && priority==0 situation. but
I was wrong.
So, definitely we have to fix such tmpfs streaming io issue. but anyway I
revert the regression commit at first.
This reverts commit 84b18490d1f1bc7ed5095c929f78bc002eb70f26.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/vmscan.c | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index e0e5f15bb726..3ff3311447f5 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1535,13 +1535,6 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc, unsigned long ap, fp; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); - /* If we have no swap space, do not bother scanning anon pages. */ - if (!sc->may_swap || (nr_swap_pages <= 0)) { - percent[0] = 0; - percent[1] = 100; - return; - } - 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) + @@ -1639,20 +1632,22 @@ static void shrink_zone(int priority, struct zone *zone, unsigned long nr_reclaimed = sc->nr_reclaimed; unsigned long nr_to_reclaim = sc->nr_to_reclaim; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); + int noswap = 0; - get_scan_ratio(zone, sc, percent); + /* If we have no swap space, do not bother scanning anon pages. */ + if (!sc->may_swap || (nr_swap_pages <= 0)) { + noswap = 1; + percent[0] = 0; + percent[1] = 100; + } else + get_scan_ratio(zone, sc, percent); for_each_evictable_lru(l) { int file = is_file_lru(l); unsigned long scan; - if (percent[file] == 0) { - nr[l] = 0; - continue; - } - scan = zone_nr_lru_pages(zone, sc, l); - if (priority) { + if (priority || noswap) { scan >>= priority; scan = (scan * percent[file]) / 100; } |