diff options
| author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2010-08-09 17:19:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-09 20:45:02 -0700 |
| commit | 58c37f6e0dfaaab85a3c11fcbf24451dfe70c721 (patch) | |
| tree | f1d6f6299059e5aa5fc3668ef9f561605491deb3 /mm/vmscan.c | |
| parent | 15748048991e801a2d18ce5da4e0d528852bc106 (diff) | |
| download | lwn-58c37f6e0dfaaab85a3c11fcbf24451dfe70c721.tar.gz lwn-58c37f6e0dfaaab85a3c11fcbf24451dfe70c721.zip | |
vmscan: protect reading of reclaim_stat with lru_lock
Rik van Riel pointed out reading reclaim_stat should be protected
lru_lock, otherwise vmscan might sweep 2x much pages.
This fault was introduced by
commit 4f98a2fee8acdb4ac84545df98cccecfd130f8db
Author: Rik van Riel <riel@redhat.com>
Date: Sat Oct 18 20:26:32 2008 -0700
vmscan: split LRU lists into anon & file sets
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 1b4e4a597caa..a3d669f8e25e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1628,6 +1628,13 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, } /* + * With swappiness at 100, anonymous and file have the same priority. + * This scanning priority is essentially the inverse of IO cost. + */ + anon_prio = sc->swappiness; + file_prio = 200 - sc->swappiness; + + /* * OK, so we have swap space and a fair amount of page cache * pages. We use the recently rotated / recently scanned * ratios to determine how valuable each cache is. @@ -1638,28 +1645,18 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, * * anon in [0], file in [1] */ + spin_lock_irq(&zone->lru_lock); if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) { - spin_lock_irq(&zone->lru_lock); reclaim_stat->recent_scanned[0] /= 2; reclaim_stat->recent_rotated[0] /= 2; - spin_unlock_irq(&zone->lru_lock); } if (unlikely(reclaim_stat->recent_scanned[1] > file / 4)) { - spin_lock_irq(&zone->lru_lock); reclaim_stat->recent_scanned[1] /= 2; reclaim_stat->recent_rotated[1] /= 2; - spin_unlock_irq(&zone->lru_lock); } /* - * With swappiness at 100, anonymous and file have the same priority. - * This scanning priority is essentially the inverse of IO cost. - */ - anon_prio = sc->swappiness; - file_prio = 200 - sc->swappiness; - - /* * The amount of pressure on anon vs file pages is inversely * proportional to the fraction of recently scanned pages on * each list that were recently referenced and in active use. @@ -1669,6 +1666,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1); fp /= reclaim_stat->recent_rotated[1] + 1; + spin_unlock_irq(&zone->lru_lock); fraction[0] = ap; fraction[1] = fp; |