From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754205AbdIIXGO (ORCPT ); Sat, 9 Sep 2017 19:06:14 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43076 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754102AbdIIXEi (ORCPT ); Sat, 9 Sep 2017 19:04:38 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Punit Agrawal" , "James Morse" , "Linus Torvalds" , "Naoya Horiguchi" Date: Sat, 09 Sep 2017 22:47:15 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 198/233] mm/memory-failure.c: use compound_head() flags for huge pages In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.48-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: James Morse commit 7258ae5c5a2ce2f5969e8b18b881be40ab55433d upstream. memory_failure() chooses a recovery action function based on the page flags. For huge pages it uses the tail page flags which don't have anything interesting set, resulting in: > Memory failure: 0x9be3b4: Unknown page state > Memory failure: 0x9be3b4: recovery action for unknown page: Failed Instead, save a copy of the head page's flags if this is a huge page, this means if there are no relevant flags for this tail page, we use the head pages flags instead. This results in the me_huge_page() recovery action being called: > Memory failure: 0x9b7969: recovery action for huge page: Delayed For hugepages that have not yet been allocated, this allows the hugepage to be dequeued. Fixes: 524fca1e7356 ("HWPOISON: fix misjudgement of page_action() for errors on mlocked pages") Link: http://lkml.kernel.org/r/20170524130204.21845-1-james.morse@arm.com Signed-off-by: James Morse Tested-by: Punit Agrawal Acked-by: Punit Agrawal Acked-by: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- mm/memory-failure.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1179,7 +1179,10 @@ int memory_failure(unsigned long pfn, in * page_remove_rmap() in try_to_unmap_one(). So to determine page status * correctly, we save a copy of the page flags at this time. */ - page_flags = p->flags; + if (PageHuge(p)) + page_flags = hpage->flags; + else + page_flags = p->flags; /* * unpoison always clear PG_hwpoison inside page lock