From: Andrew Morton __zone_reclaim() isn't modifying zone->prev_priority. But zone->prev_priority is used in the decision whether or not to bring mapped pages onto the inactive list. Hence there's a risk here that __zone_reclaim() will fail because zone->prev_priority ir large (ie: low urgency) and lots of mapped pages end up stuck on the active list. Fix that up by decreasing (ie making more urgent) zone->prev_priority as __zone_reclaim() scans the zone's pages. This bug perhaps explains why ZONE_RECLAIM_PRIORITY was created. It should be possible to remove that now, and to just start out at DEF_PRIORITY? Cc: Martin Bligh Cc: Nick Piggin Cc: Christoph Lameter Signed-off-by: Andrew Morton --- mm/vmscan.c | 1 + 1 files changed, 1 insertion(+) diff -puN mm/vmscan.c~vmscan-fix-temp_priority-in-__zone-reclaim mm/vmscan.c --- a/mm/vmscan.c~vmscan-fix-temp_priority-in-__zone-reclaim +++ a/mm/vmscan.c @@ -1640,6 +1640,7 @@ static int __zone_reclaim(struct zone *z */ priority = ZONE_RECLAIM_PRIORITY; do { + note_zone_scanning_priority(zone, priority); nr_reclaimed += shrink_zone(priority, zone, &sc); priority--; } while (priority >= 0 && nr_reclaimed < nr_pages); _