diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index dfc2452ccb10..18fed8b67943 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -149,6 +149,8 @@ struct zone { * as it fails a watermark_ok() in __alloc_pages? */ int reclaim_pages; + /* A count of how many reclaimers are scanning this zone */ + atomic_t reclaim_in_progress; /* * prev_priority holds the scanning priority for this zone. It is diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a9da20bc2ed0..2019c1b19254 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1738,6 +1738,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat, zone->nr_scan_inactive = 0; zone->nr_active = 0; zone->nr_inactive = 0; + atomic_set(&zone->reclaim_in_progress, -1); if (!size) continue; diff --git a/mm/vmscan.c b/mm/vmscan.c index 7da846960d8a..24da725a30f0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -900,7 +900,9 @@ shrink_caches(struct zone **zones, struct scan_control *sc) if (zone->all_unreclaimable && sc->priority != DEF_PRIORITY) continue; /* Let kswapd poll it */ + atomic_inc(&zone->reclaim_in_progress); shrink_zone(zone, sc); + atomic_dec(&zone->reclaim_in_progress); } } @@ -1111,7 +1113,9 @@ scan: sc.nr_reclaimed = 0; sc.priority = priority; sc.swap_cluster_max = nr_pages? nr_pages : SWAP_CLUSTER_MAX; + atomic_inc(&zone->reclaim_in_progress); shrink_zone(zone, &sc); + atomic_dec(&zone->reclaim_in_progress); reclaim_state->reclaimed_slab = 0; nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL, lru_pages); @@ -1354,9 +1358,15 @@ int zone_reclaim(struct zone *zone, unsigned int gfp_mask, unsigned int order) else sc.swap_cluster_max = SWAP_CLUSTER_MAX; + /* Don't reclaim the zone if there are other reclaimers active */ + if (!atomic_inc_and_test(&zone->reclaim_in_progress)) + goto out; + shrink_zone(zone, &sc); total_reclaimed = sc.nr_reclaimed; + out: + atomic_dec(&zone->reclaim_in_progress); return total_reclaimed; }