Commit 32665f2b authored Jan 21, 2014 by Joonsoo Kim Committed by Linus Torvalds Jan 21, 2014

mm/migrate: correct failure handling if !hugepage_migration_support()



We should remove the page from the list if we fail with ENOSYS, since
migrate_pages() consider error cases except -ENOMEM and -EAGAIN as
permanent failure and it assumes that the page would be removed from the
list.  Without this patch, we could overcount number of failure.

In addition, we should put back the new hugepage if
!hugepage_migration_support().  If not, we would leak hugepage memory.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 354a3363

mm/migrate.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -1013,7 +1013,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
		{
		int rc = 0;
		int *result = NULL;
		struct page *new_hpage = get_new_page(hpage, private, &result);
		struct page *new_hpage;
		struct anon_vma *anon_vma = NULL;

		/*
		@@ -1023,9 +1023,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
		* tables or check whether the hugepage is pmd-based or not before
		* kicking migration.
		*/
		if (!hugepage_migration_support(page_hstate(hpage)))
		if (!hugepage_migration_support(page_hstate(hpage))) {
		putback_active_hugepage(hpage);
		return -ENOSYS;
		}

		new_hpage = get_new_page(hpage, private, &result);
		if (!new_hpage)
		return -ENOMEM;