From: Martin Bligh Another bug is that if try_to_free_pages / balance_pgdat are called with a gfp_mask specifying GFP_IO and/or GFP_FS, they may reclaim the requisite number of pages, and reset prev_priority to DEF_PRIORITY. However, another reclaimer without those gfp_mask flags set may still be struggling to reclaim pages. The easy fix for this is to key the distress calculation not off zone->prev_priority, but also take into account the local caller's priority by using: min(zone->prev_priority, sc->priority) Signed-off-by: Martin J. Bligh Signed-off-by: Andrew Morton --- mm/vmscan.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff -puN mm/vmscan.c~use-min-of-two-prio-settings-in-calculating-distress-for mm/vmscan.c --- a/mm/vmscan.c~use-min-of-two-prio-settings-in-calculating-distress-for +++ a/mm/vmscan.c @@ -746,7 +746,7 @@ static inline int zone_is_near_oom(struc * But we had to alter page->flags anyway. */ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, - struct scan_control *sc) + struct scan_control *sc, int priority) { unsigned long pgmoved; int pgdeactivate = 0; @@ -770,7 +770,7 @@ static void shrink_active_list(unsigned * `distress' is a measure of how much trouble we're having * reclaiming pages. 0 -> no problems. 100 -> great trouble. */ - distress = 100 >> zone->prev_priority; + distress = 100 >> min(zone->prev_priority, priority); /* * The point of this algorithm is to decide when to start @@ -922,7 +922,7 @@ static unsigned long shrink_zone(int pri nr_to_scan = min(nr_active, (unsigned long)sc->swap_cluster_max); nr_active -= nr_to_scan; - shrink_active_list(nr_to_scan, zone, sc); + shrink_active_list(nr_to_scan, zone, sc, priority); } if (nr_inactive) { @@ -1365,7 +1365,7 @@ static unsigned long shrink_all_zones(un if (zone->nr_scan_active >= nr_pages || pass > 3) { zone->nr_scan_active = 0; nr_to_scan = min(nr_pages, zone->nr_active); - shrink_active_list(nr_to_scan, zone, sc); + shrink_active_list(nr_to_scan, zone, sc, prio); } } _