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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 6CB29C433ED for ; Wed, 21 Apr 2021 08:58:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 312EA61437 for ; Wed, 21 Apr 2021 08:58:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235546AbhDUI7Q (ORCPT ); Wed, 21 Apr 2021 04:59:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236099AbhDUI7M (ORCPT ); Wed, 21 Apr 2021 04:59:12 -0400 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD44FC06174A for ; Wed, 21 Apr 2021 01:58:39 -0700 (PDT) Received: by mail-pf1-x42c.google.com with SMTP id c3so9324086pfo.3 for ; Wed, 21 Apr 2021 01:58:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Lr+Ycz6BuRbj33U2Is4Kuv/TVfp1al5FWNN9+J922js=; b=tRjtVdEqhhlRAjKgKXlbefmzETj4mNJWhRBUZVYMAEo72hE6RBbxhMYaJhCw+bH7bn z0kM0qYsaSDqyVz/z9UH8gQa/uyDPGRMrvBW0RT+YNUe3QvRAbSwNwQkCJ/gbZCJ8OOE uRDCjO/udzAoq1yXIRXo8/bqJGFfL8z8SWxaMC+7Ey0fcin/LtJ2AKzJT5ceUSeKYFvp JXAtXjDt6zcTnfsyCilxszx/GKDsZZIZLtZnLAwvBTSK3fAwKyTspTOOckEZBzdh0ybs QS7eVcVxUa1LmxprgHmoTKesXV6qOLjJzNg81grc3ejEBIujVJR5b/oJ01ymn/gAqfQZ WU6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Lr+Ycz6BuRbj33U2Is4Kuv/TVfp1al5FWNN9+J922js=; b=ZGuGOepeqK6P+DmuWjt0058KTXzh6bxtqMrkFYVvyQgwMrX5uNgfMK5Ick21R4OTc+ xvyTyfnZDskeBk1xJ14cuu75+pOlUZN908Ge2IUhlvqHCHoX8p8ZAOqfYiRD6lMC25rR xt0TZTY6d00jHqFQ0vaYHi+/eo9JFm5MkmOwWHiddL8V2wD0RkjLAS40nfSTLceVTzhx Ck54RzHIM7ZeP3NjNXonXm+b3+mFzIN0WKxzRojcCTMEfpUs2hg+7JpiDv282QNxLlS/ H69hlrk0OrUf2A9w75FMe/sQ2Ndkz9FsGhdi92/vTrO5ul09ceCIgZfka8A0tA5p6k9R Kc+w== X-Gm-Message-State: AOAM531V1M6xl1VhnaYazbg5SqnCssIZl242g4Z98+Y6n+04oseg1v60 UD0HDXfzhDVZTKbB9cMBnA6/vSijTouuZQhYScvuL5Th/6Y4Pg== X-Google-Smtp-Source: ABdhPJykDmmu4Ncb1pa1fieQO2qdC4OFg3yF7VCrBNV7KetM5geUXbnStkkTpc8y2MM05DtUzuv4fcu8LrQe7oaGyg8= X-Received: by 2002:a17:90a:644b:: with SMTP id y11mr9679126pjm.229.1618995519230; Wed, 21 Apr 2021 01:58:39 -0700 (PDT) MIME-Version: 1.0 References: <20210421060259.67554-1-songmuchun@bytedance.com> <20210421082103.GE22456@linux> <20210421084911.GH22456@linux> In-Reply-To: <20210421084911.GH22456@linux> From: Muchun Song Date: Wed, 21 Apr 2021 16:58:02 +0800 Message-ID: Subject: Re: [External] Re: [PATCH] mm: hugetlb: fix a race between memory-failure/soft_offline and gather_surplus_pages To: Oscar Salvador Cc: Michal Hocko , Mike Kravetz , Andrew Morton , Linux Memory Management List , LKML , Naoya Horiguchi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 21, 2021 at 4:49 PM Oscar Salvador wrote: > > On Wed, Apr 21, 2021 at 04:41:10PM +0800, Muchun Song wrote: > > > But softoffline does not set page hwpoison before > > __get_hwpoison_page(). So the page still can be > > allocated. Right? > > Yep, soft_offline() only marks the page as hwpoison once the page has been > fully contended and no other use is possible. > But yeah, hugetlb is a bit trickier in that regard. > > This needs fixing in there. It is OK to fix it in softoffline/memory-failure. I just want to expose the race. Thanks. > > > -- > Oscar Salvador > SUSE L3 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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 0F861C433B4 for ; Wed, 21 Apr 2021 08:58:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8B65E61445 for ; Wed, 21 Apr 2021 08:58:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8B65E61445 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=bytedance.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0CD086B006E; Wed, 21 Apr 2021 04:58:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 07EB36B0070; Wed, 21 Apr 2021 04:58:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E12936B0071; Wed, 21 Apr 2021 04:58:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0244.hostedemail.com [216.40.44.244]) by kanga.kvack.org (Postfix) with ESMTP id C8D546B006E for ; Wed, 21 Apr 2021 04:58:41 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 81BC582499B9 for ; Wed, 21 Apr 2021 08:58:41 +0000 (UTC) X-FDA: 78055773642.30.F327873 Received: from mail-pf1-f178.google.com (mail-pf1-f178.google.com [209.85.210.178]) by imf26.hostedemail.com (Postfix) with ESMTP id 112D040002DA for ; Wed, 21 Apr 2021 08:58:33 +0000 (UTC) Received: by mail-pf1-f178.google.com with SMTP id a12so28118512pfc.7 for ; Wed, 21 Apr 2021 01:58:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Lr+Ycz6BuRbj33U2Is4Kuv/TVfp1al5FWNN9+J922js=; b=tRjtVdEqhhlRAjKgKXlbefmzETj4mNJWhRBUZVYMAEo72hE6RBbxhMYaJhCw+bH7bn z0kM0qYsaSDqyVz/z9UH8gQa/uyDPGRMrvBW0RT+YNUe3QvRAbSwNwQkCJ/gbZCJ8OOE uRDCjO/udzAoq1yXIRXo8/bqJGFfL8z8SWxaMC+7Ey0fcin/LtJ2AKzJT5ceUSeKYFvp JXAtXjDt6zcTnfsyCilxszx/GKDsZZIZLtZnLAwvBTSK3fAwKyTspTOOckEZBzdh0ybs QS7eVcVxUa1LmxprgHmoTKesXV6qOLjJzNg81grc3ejEBIujVJR5b/oJ01ymn/gAqfQZ WU6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Lr+Ycz6BuRbj33U2Is4Kuv/TVfp1al5FWNN9+J922js=; b=b5ijM9y6OVn/oTMNRcXLU49XC9ml/rSv4CHoZBTqIKNS8DyG6r+srsKhqhB9ArS4mx NLlgbxiFBIIMqnxCsTWhpTQRKO3nd+tH54+BuOg4SGZx9RhArkQ4UHsjsZ6X9hwxas5C gF2e9q4LucwNdGEesiKXM2Hx8ljzBPDC+5Rh6qzBJ9RCkVncgwp6ctp8SOfZJFjsHk8p vRBMZjKaKwB3rQZjC/lzAUQs1w4iLPszYT2RAb+qbMRPo6nayujmDhwDftq6LlDR61gI DHJ4f3dv8iiuSQaPRhlfa2PH7qn3lyNKvmVTfDs8PztJDfARJ3ictFj9pEgPlPo7cQow FxsQ== X-Gm-Message-State: AOAM531SH0FBqh7YWqTeI29/TiIlN6gaCn84ki55xvVGw2vy6ayyMIZg eJKUzzibvkY4ylioUhg6355MuSyIYPcv+1kQE4bk/g== X-Google-Smtp-Source: ABdhPJykDmmu4Ncb1pa1fieQO2qdC4OFg3yF7VCrBNV7KetM5geUXbnStkkTpc8y2MM05DtUzuv4fcu8LrQe7oaGyg8= X-Received: by 2002:a17:90a:644b:: with SMTP id y11mr9679126pjm.229.1618995519230; Wed, 21 Apr 2021 01:58:39 -0700 (PDT) MIME-Version: 1.0 References: <20210421060259.67554-1-songmuchun@bytedance.com> <20210421082103.GE22456@linux> <20210421084911.GH22456@linux> In-Reply-To: <20210421084911.GH22456@linux> From: Muchun Song Date: Wed, 21 Apr 2021 16:58:02 +0800 Message-ID: Subject: Re: [External] Re: [PATCH] mm: hugetlb: fix a race between memory-failure/soft_offline and gather_surplus_pages To: Oscar Salvador Cc: Michal Hocko , Mike Kravetz , Andrew Morton , Linux Memory Management List , LKML , Naoya Horiguchi Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 112D040002DA X-Stat-Signature: bmehhfdi96366cgdmyxa47srfyj4637q Received-SPF: none (bytedance.com>: No applicable sender policy available) receiver=imf26; identity=mailfrom; envelope-from=""; helo=mail-pf1-f178.google.com; client-ip=209.85.210.178 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1618995513-814193 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 Wed, Apr 21, 2021 at 4:49 PM Oscar Salvador wrote: > > On Wed, Apr 21, 2021 at 04:41:10PM +0800, Muchun Song wrote: > > > But softoffline does not set page hwpoison before > > __get_hwpoison_page(). So the page still can be > > allocated. Right? > > Yep, soft_offline() only marks the page as hwpoison once the page has been > fully contended and no other use is possible. > But yeah, hugetlb is a bit trickier in that regard. > > This needs fixing in there. It is OK to fix it in softoffline/memory-failure. I just want to expose the race. Thanks. > > > -- > Oscar Salvador > SUSE L3