Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[sfrench/cifs-2.6.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3334a769eb91e1c1cc374560125c8c64e32da979..15c2050c629b1d8aacb2f36aac7ac09c54c95449 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4467,6 +4467,28 @@ retry_cpuset:
                if (page)
                        goto got_pg;
 
+                if (order >= pageblock_order && (gfp_mask & __GFP_IO)) {
+                       /*
+                        * If allocating entire pageblock(s) and compaction
+                        * failed because all zones are below low watermarks
+                        * or is prohibited because it recently failed at this
+                        * order, fail immediately.
+                        *
+                        * Reclaim is
+                        *  - potentially very expensive because zones are far
+                        *    below their low watermarks or this is part of very
+                        *    bursty high order allocations,
+                        *  - not guaranteed to help because isolate_freepages()
+                        *    may not iterate over freed pages as part of its
+                        *    linear scan, and
+                        *  - unlikely to make entire pageblocks free on its
+                        *    own.
+                        */
+                       if (compact_result == COMPACT_SKIPPED ||
+                           compact_result == COMPACT_DEFERRED)
+                               goto nopage;
+               }
+
                /*
                 * Checks for costly allocations with __GFP_NORETRY, which
                 * includes THP page fault allocations