Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 17497d0cd8b9e4c95bf5ce39abf1f59d2eb15f2f..6771ea70bfe7e399d96237a58d3860357aad4c46 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1841,16 +1841,28 @@ static inline bool should_continue_reclaim(struct zone *zone,
        if (!(sc->reclaim_mode & RECLAIM_MODE_COMPACTION))
                return false;
 
-       /*
-        * If we failed to reclaim and have scanned the full list, stop.
-        * NOTE: Checking just nr_reclaimed would exit reclaim/compaction far
-        *       faster but obviously would be less likely to succeed
-        *       allocation. If this is desirable, use GFP_REPEAT to decide
-        *       if both reclaimed and scanned should be checked or just
-        *       reclaimed
-        */
-       if (!nr_reclaimed && !nr_scanned)
-               return false;
+       /* Consider stopping depending on scan and reclaim activity */
+       if (sc->gfp_mask & __GFP_REPEAT) {
+               /*
+                * For __GFP_REPEAT allocations, stop reclaiming if the
+                * full LRU list has been scanned and we are still failing
+                * to reclaim pages. This full LRU scan is potentially
+                * expensive but a __GFP_REPEAT caller really wants to succeed
+                */
+               if (!nr_reclaimed && !nr_scanned)
+                       return false;
+       } else {
+               /*
+                * For non-__GFP_REPEAT allocations which can presumably
+                * fail without consequence, stop if we failed to reclaim
+                * any pages from the last SWAP_CLUSTER_MAX number of
+                * pages that were scanned. This will return to the
+                * caller faster at the risk reclaim/compaction and
+                * the resulting allocation attempt fails
+                */
+               if (!nr_reclaimed)
+                       return false;
+       }
 
        /*
         * If we have not reclaimed enough pages for compaction and the