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>
+ /*
+ * 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
/*
* OK, so we have swap space and a fair amount of page cache
* pages. We use the recently rotated / recently scanned
*
* anon in [0], file in [1]
*/
*
* anon in [0], file in [1]
*/
+ spin_lock_irq(&zone->lru_lock);
if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
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;
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)) {
}
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;
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
/*
* The amount of pressure on anon vs file pages is inversely
* proportional to the fraction of recently scanned pages on
fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
fp /= reclaim_stat->recent_rotated[1] + 1;
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;
fraction[0] = ap;
fraction[1] = fp;