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authorWeijie Yang <weijie.yang@samsung.com>2014-04-07 15:36:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-07 16:35:50 -0700
commit619d0d76c1ee943f171c7d4fc021ec7602388579 (patch)
tree1a2bff9a01509f95031157f3a84b44dead8e7d3f /mm/vmscan.c
parenta5338093bfb462256f70f3450c08f73e59543e26 (diff)
downloadlwn-619d0d76c1ee943f171c7d4fc021ec7602388579.tar.gz
lwn-619d0d76c1ee943f171c7d4fc021ec7602388579.zip
mm/vmscan: restore sc->gfp_mask after promoting it to __GFP_HIGHMEM
We promote sc->gfp_mask to __GFP_HIGHMEM to forcibly scan highmem if there are too many buffer_heads pinning highmem. See cc715d99e5 ("mm: vmscan: forcibly scan highmem if there are too many buffer_heads pinning highmem"). This patch restores sc->gfp_mask to its caller original value after finishing the scan job, to avoid the impact on other invocations from its upper caller, such as vmpressure_prio(), shrink_slab(). Signed-off-by: Weijie Yang <weijie.yang@samsung.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1f56a80a7c41..1c51e4f52fd9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2314,6 +2314,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
unsigned long lru_pages = 0;
bool aborted_reclaim = false;
struct reclaim_state *reclaim_state = current->reclaim_state;
+ gfp_t orig_mask;
struct shrink_control shrink = {
.gfp_mask = sc->gfp_mask,
};
@@ -2323,6 +2324,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
* allowed level, force direct reclaim to scan the highmem zone as
* highmem pages could be pinning lowmem pages storing buffer_heads
*/
+ orig_mask = sc->gfp_mask;
if (buffer_heads_over_limit)
sc->gfp_mask |= __GFP_HIGHMEM;
@@ -2393,6 +2395,12 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
}
}
+ /*
+ * Restore to original mask to avoid the impact on the caller if we
+ * promoted it to __GFP_HIGHMEM.
+ */
+ sc->gfp_mask = orig_mask;
+
return aborted_reclaim;
}