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=ham 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 3E767C4338F for ; Thu, 12 Aug 2021 10:56:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B2DA60FC3 for ; Thu, 12 Aug 2021 10:56:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236620AbhHLK4g (ORCPT ); Thu, 12 Aug 2021 06:56:36 -0400 Received: from outbound-smtp35.blacknight.com ([46.22.139.218]:36055 "EHLO outbound-smtp35.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236442AbhHLK4f (ORCPT ); Thu, 12 Aug 2021 06:56:35 -0400 Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp35.blacknight.com (Postfix) with ESMTPS id 58F9F1E45 for ; Thu, 12 Aug 2021 11:56:09 +0100 (IST) Received: (qmail 10232 invoked from network); 12 Aug 2021 10:56:09 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.255]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 12 Aug 2021 10:56:09 -0000 Date: Thu, 12 Aug 2021 11:56:07 +0100 From: Mel Gorman To: Doug Berger Cc: Andrew Morton , Vlastimil Babka , "Peter Zijlstra (Intel)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/page_alloc: don't corrupt pcppage_migratetype Message-ID: <20210812105607.GK6464@techsingularity.net> References: <20210811182917.2607994-1-opendmb@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20210811182917.2607994-1-opendmb@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 11, 2021 at 11:29:17AM -0700, Doug Berger wrote: > When placing pages on a pcp list, migratetype values over > MIGRATE_PCPTYPES get added to the MIGRATE_MOVABLE pcp list. > > However, the actual migratetype is preserved in the page and > should not be changed to MIGRATE_MOVABLE or the page may end > up on the wrong free_list. > > Fixes: df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock") > Signed-off-by: Doug Berger Oops, yes. The impact is that HIGHATOMIC or CMA pages getting bulk freed from the PCP lists could potentially end up on the wrong buddy list. There are various consequences but minimally NR_FREE_CMA_PAGES accounting could get screwed up. Thanks Doug Acked-by: Mel Gorman -- Mel Gorman SUSE Labs