From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C75FCA9EA1 for ; Fri, 18 Oct 2019 11:48:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 45FBB20700 for ; Fri, 18 Oct 2019 11:48:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 45FBB20700 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CFFF38E0005; Fri, 18 Oct 2019 07:48:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C89C58E0003; Fri, 18 Oct 2019 07:48:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B78198E0005; Fri, 18 Oct 2019 07:48:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0020.hostedemail.com [216.40.44.20]) by kanga.kvack.org (Postfix) with ESMTP id 90B7B8E0003 for ; Fri, 18 Oct 2019 07:48:35 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 2A1D3180ABF5F for ; Fri, 18 Oct 2019 11:48:35 +0000 (UTC) X-FDA: 76056732990.07.group91_2dcee82f78f30 X-HE-Tag: group91_2dcee82f78f30 X-Filterd-Recvd-Size: 2353 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Fri, 18 Oct 2019 11:48:34 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3F776B537; Fri, 18 Oct 2019 11:48:33 +0000 (UTC) Date: Fri, 18 Oct 2019 13:48:32 +0200 From: Michal Hocko To: Oscar Salvador Cc: n-horiguchi@ah.jp.nec.com, mike.kravetz@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 01/16] mm,hwpoison: cleanup unused PageHuge() check Message-ID: <20191018114832.GK5017@dhcp22.suse.cz> References: <20191017142123.24245-1-osalvador@suse.de> <20191017142123.24245-2-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191017142123.24245-2-osalvador@suse.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu 17-10-19 16:21:08, Oscar Salvador wrote: > From: Naoya Horiguchi > > Drop the PageHuge check since memory_failure forks into memory_failure_hugetlb() > for hugetlb pages. > > Signed-off-by: Oscar Salvador > Signed-off-by: Naoya Horiguchi s-o-b chain is reversed. The code is a bit confusing. Doesn't this check aim for THP? AFAICS PageTransHuge(hpage) will split the THP or fail so PageTransHuge shouldn't be possible anymore, right? But why does hwpoison_user_mappings still work with hpage then? > --- > mm/memory-failure.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 05c8c6df25e6..2cbadb58c7df 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1345,10 +1345,7 @@ int memory_failure(unsigned long pfn, int flags) > * 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. > */ > - if (PageHuge(p)) > - page_flags = hpage->flags; > - else > - page_flags = p->flags; > + page_flags = p->flags; > > /* > * unpoison always clear PG_hwpoison inside page lock > -- > 2.12.3 -- Michal Hocko SUSE Labs