3.18-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 3aaa76e125c1dd58c9b599baa8c6021896874c12 ]
Since commit bcc54222309c ("mm: hugetlb: introduce page_huge_active") each hugetlb page maintains its active flag to avoid a race condition betwe= en multiple calls of isolate_huge_page(), but current kernel doesn't set the f= lag on a hugepage allocated by migration because the proper putback routine isn= 't called. This means that users could still encounter the race referred to by bcc54222309c in this special case, so this patch fixes it.
Fixes: bcc54222309c ("mm: hugetlb: introduce page_huge_active") Signed-off-by: Naoya Horiguchi n-horiguchi@ah.jp.nec.com Cc: Michal Hocko mhocko@suse.cz Cc: Andi Kleen andi@firstfloor.org Cc: Hugh Dickins hughd@google.com Cc: stable@vger.kernel.org [4.1.x] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/migrate.c b/mm/migrate.c index 4d743bce5a23..57559f9295f9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1077,7 +1077,7 @@ out: if (rc != MIGRATEPAGE_SUCCESS && put_new_page) put_new_page(new_hpage, private); else - put_page(new_hpage); + putback_active_hugepage(new_hpage);
if (result) { if (rc)