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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, 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 D532BC433E0 for ; Fri, 5 Mar 2021 07:27:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0CDC165019 for ; Fri, 5 Mar 2021 07:27:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0CDC165019 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0B2976B0005; Fri, 5 Mar 2021 02:27:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 03AFD6B0007; Fri, 5 Mar 2021 02:27:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF7916B0008; Fri, 5 Mar 2021 02:27:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id BFEAC6B0005 for ; Fri, 5 Mar 2021 02:27:03 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 81D16249E for ; Fri, 5 Mar 2021 07:27:03 +0000 (UTC) X-FDA: 77884989126.15.37FB4A8 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf08.hostedemail.com (Postfix) with ESMTP id 1172880192D8 for ; Fri, 5 Mar 2021 07:26:59 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9CDB4AF10; Fri, 5 Mar 2021 07:27:01 +0000 (UTC) Date: Fri, 5 Mar 2021 08:26:58 +0100 From: Oscar Salvador To: Naoya Horiguchi Cc: linux-mm@kvack.org, Andrew Morton , Michal Hocko , Tony Luck , "Aneesh Kumar K.V" , Naoya Horiguchi , linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] mm, hwpoison: do not lock page again when me_huge_page() successfully recovers Message-ID: <20210305072652.GA18868@linux> References: <20210304064437.962442-1-nao.horiguchi@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210304064437.962442-1-nao.horiguchi@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 1172880192D8 X-Stat-Signature: aisdqeds3xqjkx5kpjiw4q8ac7kmu4mc Received-SPF: none (suse.de>: No applicable sender policy available) receiver=imf08; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: none/none X-HE-Tag: 1614929219-653316 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, Mar 04, 2021 at 03:44:37PM +0900, Naoya Horiguchi wrote: > From: Naoya Horiguchi Hi Naoya, good catch! > Currently me_huge_page() temporary unlocks page to perform some actions > then locks it again later. My testcase (which calls hard-offline on some > tail page in a hugetlb, then accesses the address of the hugetlb range) > showed that page allocation code detects the page lock on buddy page and > printed out "BUG: Bad page state" message. PG_hwpoison does not prevent > it because PG_hwpoison flag is set on any subpage of the hugetlb page > but the 2nd page lock is on the head page. I am having difficulties to parse "PG_hwpoison does not prevent it because PG_hwpoison flag is set on any subpage of the hugetlb page". What do you mean by that? > > This patch suggests to drop the 2nd page lock to fix the issue. > > Fixes: commit 78bb920344b8 ("mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error") > Cc: stable@vger.kernel.org > Signed-off-by: Naoya Horiguchi The fix looks fine to me: Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE L3