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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 53D00C433E0 for ; Fri, 19 Mar 2021 13:22:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E068064ED7 for ; Fri, 19 Mar 2021 13:22:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E068064ED7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 622176B0072; Fri, 19 Mar 2021 09:22:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5D1D28D0005; Fri, 19 Mar 2021 09:22:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 487F08D0003; Fri, 19 Mar 2021 09:22:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0195.hostedemail.com [216.40.44.195]) by kanga.kvack.org (Postfix) with ESMTP id 2B7236B0072 for ; Fri, 19 Mar 2021 09:22:50 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id E538818162A6D for ; Fri, 19 Mar 2021 13:22:49 +0000 (UTC) X-FDA: 77936688858.29.2B964CA Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf06.hostedemail.com (Postfix) with ESMTP id F235AC0001F7 for ; Fri, 19 Mar 2021 13:22:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2KS9BVm2N7BFC51UrW+/8IGJ0MRGc1xx7mmgTk+g7Ck=; b=n3IUUh3aXo0JWD2wwOFW2ef/JX 7he8eoKNWqSKvmwXduCO9vGrHKcg6SnwHcWTHJz45edEUqaq/hk8q727hY2kq9y+jTFam61GWQrhG fmfHy5usrFG5GE9yqN8jAw8ePQ6miFu5YdhdXtNUwb1GYKYsbxiX8h/xOTD7qgAT3ZAhYH9G+vjhe L8g1fXJrm4rd3vUE4Ho2bTvg3vU4DixQcHhX1a/yYR/xYepeqAIlRcNguEJRERXQcB9jfShsBIsie liOlvmtwm1KYswYxVtFGkUXreaphaYAvVDtIZ/CKukhYqlB5DpNYwgkol/zsXmaXvINPWvHH8E2V3 H2OmBNDA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lNF4L-004Rbo-Ez; Fri, 19 Mar 2021 13:21:42 +0000 Date: Fri, 19 Mar 2021 13:21:37 +0000 From: Matthew Wilcox To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , Hugh Dickins , Zhou Guanghui , Zi Yan , Shakeel Butt , Roman Gushchin , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH] mm: page_alloc: fix memcg accounting leak in speculative cache lookup Message-ID: <20210319132137.GZ3420@casper.infradead.org> References: <20210319071547.60973-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210319071547.60973-1-hannes@cmpxchg.org> X-Stat-Signature: g5gtp185hhg1frgs3qme64ehh95ug883 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: F235AC0001F7 Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf06; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616160163-398651 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 Fri, Mar 19, 2021 at 03:15:47AM -0400, Johannes Weiner wrote: > When the freeing of a higher-order page block (non-compound) races > with a speculative page cache lookup, __free_pages() needs to leave > the first order-0 page in the chunk to the lookup but free the buddy > pages that the lookup doesn't know about separately. Thanks.