From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753322Ab1JYGk3 (ORCPT ); Tue, 25 Oct 2011 02:40:29 -0400 Received: from smtp-out.google.com ([74.125.121.67]:17643 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751436Ab1JYGk2 (ORCPT ); Tue, 25 Oct 2011 02:40:28 -0400 From: Colin Cross To: linux-kernel@vger.kernel.org Cc: Colin Cross , Andrew Morton , Mel Gorman , KAMEZAWA Hiroyuki , Andrea Arcangeli , David Rientjes , linux-mm@kvack.org Subject: [PATCH] mm: avoid livelock on !__GFP_FS allocations Date: Mon, 24 Oct 2011 23:39:49 -0700 Message-Id: <1319524789-22818-1-git-send-email-ccross@android.com> X-Mailer: git-send-email 1.7.4.1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Under the following conditions, __alloc_pages_slowpath can loop forever: gfp_mask & __GFP_WAIT is true gfp_mask & __GFP_FS is false reclaim and compaction make no progress order <= PAGE_ALLOC_COSTLY_ORDER These conditions happen very often during suspend and resume, when pm_restrict_gfp_mask() effectively converts all GFP_KERNEL allocations into __GFP_WAIT. The oom killer is not run because gfp_mask & __GFP_FS is false, but should_alloc_retry will always return true when order is less than PAGE_ALLOC_COSTLY_ORDER. Fix __alloc_pages_slowpath to skip retrying when oom killer is not allowed by the GFP flags, the same way it would skip if the oom killer was allowed but disabled. Signed-off-by: Colin Cross --- An alternative patch would add a did_some_progress argument to __alloc_pages_may_oom, and remove the checks in __alloc_pages_slowpath that require knowledge of when __alloc_pages_may_oom chooses to run out_of_memory. If did_some_progress was still zero, it would goto nopage whether or not __alloc_pages_may_oom was actually called. mm/page_alloc.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fef8dc3..dcd99b3 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2193,6 +2193,10 @@ rebalance: } goto restart; + } else { + /* If we aren't going to try the OOM killer, give up */ + if (!(gfp_mask & __GFP_NOFAIL)) + goto nopage; } } -- 1.7.4.1