HWPOISON: Use new shake_page in memory_failure
Andi Kleen [Wed, 16 Dec 2009 11:20:00 +0000 (12:20 +0100)]
shake_page handles more types of page caches than
the much simpler lru_add_drain_all:

- slab (quite inefficiently for now)
- any other caches with a shrinker callback
- per cpu page allocator pages
- per CPU LRU

Use this call to try to turn pages into free or LRU pages.
Then handle the case of the page becoming free after drain everything.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

mm/memory-failure.c

index 2d5f122..ded1d38 100644 (file)
@@ -936,8 +936,15 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
         * walked by the page reclaim code, however that's not a big loss.
         */
        if (!PageLRU(p))
-               lru_add_drain_all();
+               shake_page(p);
        if (!PageLRU(p)) {
+               /*
+                * shake_page could have turned it free.
+                */
+               if (is_free_buddy_page(p)) {
+                       action_result(pfn, "free buddy, 2nd try", DELAYED);
+                       return 0;
+               }
                action_result(pfn, "non LRU", IGNORED);
                put_page(p);
                return -EBUSY;