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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2511DC433EF for ; Fri, 11 Mar 2022 02:02:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345547AbiCKCDT (ORCPT ); Thu, 10 Mar 2022 21:03:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345520AbiCKCDM (ORCPT ); Thu, 10 Mar 2022 21:03:12 -0500 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 715771A58CD for ; Thu, 10 Mar 2022 18:02:10 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-2d07ae11462so57665977b3.8 for ; Thu, 10 Mar 2022 18:02:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=2hsaR8WAxcqWtbQLCYo/TxbTYR2phuKd4uO3CbSGXis=; b=Q4jqn7qEyVL5UGQm48tyWxHXBIKnYgeh4VJEcNABuXL8XnVgyd64deKgPWFzS66j7R g19GwgGrR2Qn0tEHazNj8b5zGGY9w6dYR/QXR3bG0gkvWfu9DJlLW79z0K/C/zsxfTge GcJ5vm2PigirvczYxMY0bKFOqMgstn4HhF3LhKS5zTfBa4NqlI/XoXoEUjMe2v7dxm83 78tk4oqkEHsC95dm3g4GEnbysiblZLmhiaBQwu415BH228ci8sg+b9UrKjafX1FBmrjF +3UHolf80KtUStuJ7TfPlOzTfUAoZ1d5e7HGQhKJXtFMuZ4vYMUHLKLRBrrn/Zia00/l V3NQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=2hsaR8WAxcqWtbQLCYo/TxbTYR2phuKd4uO3CbSGXis=; b=cRokBrlTE53oLTXt/U53qzkt4keWmw+2vFwr/ycPMnUhLTIQKeo58nacHFcWOsRBYZ O4/DCJ2zN8vrU7G2DwyOdwlho5csR1EteWWLvWB7weIibBJI/NFPejFx/LRO0fCY5x+m sgC7+5sqP6PSltnZQ+dL6uYETgnRcz5Ca4BDLX7utF04EqyxYqDHwL9tiLSu3Htm7Ldm Ku6p+oPy68GQh6r/1znZ2s/JN3QqOarUOalJpURlgUuXIc9cIxyS1XXk1xNahaQVtzAG dy0BDRr79xiQ3gHaJcsJM6Mj5rwhp4QpVtynLbydwandAxHNLPVJ3Da0LLtvhRp2olxz RDTQ== X-Gm-Message-State: AOAM5338fck1N2lrfnVBtwcXDg6ALBSwVyCnbNHpzED0yR6X52s5tkiL CmnL9wF2a8C7LdC+JMX/pwzXvWagtjtchg== X-Google-Smtp-Source: ABdhPJzOTCYYIPtqY5f4TpqaFYLmmfYjNi7qJZgtvYTI9QaocypqR0Q/Ra+o/HDjGm3UwlCg1pPVe9yP2r+USg== X-Received: from shakeelb.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:28b]) (user=shakeelb job=sendgmr) by 2002:a81:7556:0:b0:2dc:6ea9:8d53 with SMTP id q83-20020a817556000000b002dc6ea98d53mr6501468ywc.413.1646964129540; Thu, 10 Mar 2022 18:02:09 -0800 (PST) Date: Fri, 11 Mar 2022 02:02:06 +0000 In-Reply-To: <20220310092456.GJ15701@techsingularity.net> Message-Id: <20220311020206.qncvybld6zrgmm3m@google.com> Mime-Version: 1.0 References: <20220310092456.GJ15701@techsingularity.net> Subject: Re: [PATCH] mm/page_alloc: check high-order pages for corruption during PCP operations From: Shakeel Butt To: Mel Gorman Cc: Andrew Morton , Eric Dumazet , Eric Dumazet , linux-kernel , linux-mm , Vlastimil Babka , Michal Hocko , Wei Xu , Greg Thelen , Hugh Dickins , David Rientjes Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 10, 2022 at 09:24:56AM +0000, Mel Gorman wrote: > Eric Dumazet pointed out that commit 44042b449872 ("mm/page_alloc: allow > high-order pages to be stored on the per-cpu lists") only checks the head > page during PCP refill and allocation operations. This was an oversight > and all pages should be checked. This will incur a small performance > penalty but it's necessary for correctness. > Fixes: 44042b449872 ("mm/page_alloc: allow high-order pages to be stored > on the per-cpu lists") > Reported-by: Eric Dumazet > Signed-off-by: Mel Gorman > Acked-by: Eric Dumazet Reviewed-by: Shakeel Butt