summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2015-04-15 16:14:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-15 16:35:19 -0700
commit822fc61367f062d36c5b5a4d517e9bd2b65a741f (patch)
tree01e85731a4d8b4e4f9252d9e6e2e6a8e597d05ff
parent9fcd145717e6496d0c376acb1a5cc551a716c305 (diff)
mm: don't call __page_cache_release for hugetlb
__put_compound_page() calls __page_cache_release() to do some freeing work, but it's obviously for thps, not for hugetlb. We don't care because PageLRU is always cleared and page->mem_cgroup is always NULL for hugetlb. But it's not correct and has potential risks, so let's make it conditional. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/swap.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/swap.c b/mm/swap.c
index e3a4feac9b0e..a7251a8ed532 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -31,6 +31,7 @@
#include <linux/memcontrol.h>
#include <linux/gfp.h>
#include <linux/uio.h>
+#include <linux/hugetlb.h>
#include "internal.h"
@@ -75,7 +76,14 @@ static void __put_compound_page(struct page *page)
{
compound_page_dtor *dtor;
- __page_cache_release(page);
+ /*
+ * __page_cache_release() is supposed to be called for thp, not for
+ * hugetlb. This is because hugetlb page does never have PageLRU set
+ * (it's never listed to any LRU lists) and no memcg routines should
+ * be called for hugetlb (it has a separate hugetlb_cgroup.)
+ */
+ if (!PageHuge(page))
+ __page_cache_release(page);
dtor = get_compound_page_dtor(page);
(*dtor)(page);
}