There is race between do_swap_page() and swap_writepage(), if do_swap_page() had deleted a page from swap cache, there is no need to write it. So changing the ret of try_to_free_swap() to make swap_writepage() aware of this scene. Signed-off-by: Liu Ping Fan <pingfank@xxxxxxxxxxxxxxxxxx> --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 4c524f7..9d80671 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -910,7 +910,7 @@ int try_to_free_swap(struct page *page) VM_BUG_ON_PAGE(!PageLocked(page), page); if (!PageSwapCache(page)) - return 0; + return -1; if (PageWriteback(page)) return 0; if (page_swapcount(page)) -- 1.8.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>