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-rw-r--r--include/linux/mmzone.h2
-rw-r--r--mm/page_alloc.c1
-rw-r--r--mm/vmscan.c10
3 files changed, 13 insertions, 0 deletions
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;
}