mm/balloon_compaction: fix deflation when compaction is disabled

If CONFIG_BALLOON_COMPACTION=n balloon_page_insert() does not link pages
with balloon and doesn't set PagePrivate flag, as a result
balloon_page_dequeue() cannot get any pages because it thinks that all
of them are isolated.  Without balloon compaction nobody can isolate
ballooned pages.  It's safe to remove this check.

Fixes: d6d86c0a7f ("mm/balloon_compaction: redesign ballooned pages management").
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Reported-by: Matt Mullins <mmullins@mmlx.us>
Cc: <stable@vger.kernel.org>	[3.17]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Konstantin Khlebnikov 2014-10-29 14:51:02 -07:00 committed by Linus Torvalds
parent 5417421b27
commit 4d88e6f7d5
1 changed files with 2 additions and 0 deletions

View File

@ -68,11 +68,13 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info)
* to be released by the balloon driver.
*/
if (trylock_page(page)) {
#ifdef CONFIG_BALLOON_COMPACTION
if (!PagePrivate(page)) {
/* raced with isolation */
unlock_page(page);
continue;
}
#endif
spin_lock_irqsave(&b_dev_info->pages_lock, flags);
balloon_page_delete(page);
__count_vm_event(BALLOON_DEFLATE);