From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f179.google.com (mail-wi0-f179.google.com [209.85.212.179]) by kanga.kvack.org (Postfix) with ESMTP id E4ADE6B0038 for ; Thu, 16 Apr 2015 09:50:00 -0400 (EDT) Received: by wizk4 with SMTP id k4so195688623wiz.1 for ; Thu, 16 Apr 2015 06:50:00 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id az10si14054464wjb.39.2015.04.16.06.49.56 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Apr 2015 06:49:57 -0700 (PDT) Message-ID: <552FBDEC.7070108@redhat.com> Date: Thu, 16 Apr 2015 08:49:32 -0500 From: Dean Nelson MIME-Version: 1.0 Subject: Re: [PATCH] mm/memory-failure: call shake_page() when error hits thp tail page References: <1429082714-26115-1-git-send-email-n-horiguchi@ah.jp.nec.com> In-Reply-To: <1429082714-26115-1-git-send-email-n-horiguchi@ah.jp.nec.com> Content-Type: text/plain; charset=iso-2022-jp Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Andrew Morton , Andi Kleen , Andrea Arcangeli , Hidetoshi Seto , Jin Dongming , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" On 04/15/2015 02:25 AM, 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 This looks correct to me. Thanks! Acked-by: Dean Nelson > Cc: stable@vger.kernel.org # v3.4+ > --- > mm/memory-failure.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git v4.0.orig/mm/memory-failure.c v4.0/mm/memory-failure.c > index d487f8dc6d39..2cc1d578144b 100644 > --- v4.0.orig/mm/memory-failure.c > +++ v4.0/mm/memory-failure.c > @@ -1141,10 +1141,10 @@ int memory_failure(unsigned long pfn, int trapno, int flags) > * The check (unnecessarily) ignores LRU pages being isolated and > * walked by the page reclaim code, however that's not a big loss. > */ > - if (!PageHuge(p) && !PageTransTail(p)) { > - if (!PageLRU(p)) > - shake_page(p, 0); > - if (!PageLRU(p)) { > + if (!PageHuge(p)) { > + if (!PageLRU(hpage)) > + shake_page(hpage, 0); > + if (!PageLRU(hpage)) { > /* > * shake_page could have turned it free. > */ > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org