Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753327AbbDTVaS (ORCPT ); Mon, 20 Apr 2015 17:30:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:43907 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751024AbbDTVaP (ORCPT ); Mon, 20 Apr 2015 17:30:15 -0400 Date: Mon, 20 Apr 2015 14:30:14 -0700 From: Andrew Morton To: Naoya Horiguchi Cc: Dean Nelson , Andi Kleen , "Andrea Arcangeli" , Hidetoshi Seto , Jin Dongming , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] mm/memory-failure: call shake_page() when error hits thp tail page Message-Id: <20150420143014.bd6c683d159758db1815799f@linux-foundation.org> In-Reply-To: <1429082714-26115-1-git-send-email-n-horiguchi@ah.jp.nec.com> References: <1429082714-26115-1-git-send-email-n-horiguchi@ah.jp.nec.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1335 Lines: 27 On Wed, 15 Apr 2015 07:25:46 +0000 Naoya Horiguchi wrote: > Currently memory_failure() calls shake_page() to sweep pages out from pcplists > only when the victim page is 4kB LRU page or thp head page. But we should do > this for a thp tail page too. > Consider that a memory error hits a thp tail page whose head page is on a > pcplist when memory_failure() runs. Then, the current kernel skips shake_pages() > part, so hwpoison_user_mappings() returns without calling split_huge_page() nor > try_to_unmap() because PageLRU of the thp head is still cleared due to the skip > of shake_page(). > As a result, me_huge_page() runs for the thp, which is a broken behavior. > > This patch fixes this problem by calling shake_page() for thp tail case. > > Fixes: 385de35722c9 ("thp: allow a hwpoisoned head page to be put back to LRU") > Signed-off-by: Naoya Horiguchi > Cc: stable@vger.kernel.org # v3.4+ What are the userspace-visible effects of the bug? This info is needed for backporting into -stable and other kernels, please. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/