[PATCH] VM: rate limit early reclaim
[linux-2.6.git] / mm / vmscan.c
index 7da8469..24da725 100644 (file)
@@ -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;
 }