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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CD42C83F33 for ; Tue, 5 Sep 2023 06:57:45 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C42138E0020; Tue, 5 Sep 2023 02:57:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BF1F08E001A; Tue, 5 Sep 2023 02:57:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A93238E0020; Tue, 5 Sep 2023 02:57:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 95D6C8E001A for ; Tue, 5 Sep 2023 02:57:44 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 66609B3C85 for ; Tue, 5 Sep 2023 06:57:44 +0000 (UTC) X-FDA: 81201638448.17.462274E Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf05.hostedemail.com (Postfix) with ESMTP id 981E0100015 for ; Tue, 5 Sep 2023 06:57:41 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of tongtiangen@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=tongtiangen@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693897062; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gaSfgNlFvlPzGESbq6PjI583IlPVlCNrsdhNak9TDfY=; b=Ubxhj9dBRRwDdw0j1OYQxt3quSvB/G5vJy8fbDNjveZuYdxGu2g69UWOiclwxn3LZ8qQ1A gkJgl6RFqImwAC3eBuxcdU3YY+PTjWdASJkwWX0U3rDQU5qfEWqQZO8G2QCf9qsiS7KBd8 Jb74H6Wl+FtoYyGkgqJyt9oivT5xYfo= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693897062; a=rsa-sha256; cv=none; b=7keNvb8YBkkkuSOq7qb5DPCX9pNCAm2O4gcYOqqGY/4FR84yHrOe9HLR3RPkclTDFt+EYR kkR98h1vScsR0Dg5q/0WQYpqrUTbjVM+FUaa1eOGSkhOfZwqu/5qp63V3eU9REmsL6Von4 sNlfGZBXOsWRdxL5y7b9/N2rTMWXoFs= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of tongtiangen@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=tongtiangen@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com Received: from kwepemm600017.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Rfx9H0WV7zrSc9; Tue, 5 Sep 2023 14:55:47 +0800 (CST) Received: from [10.174.179.234] (10.174.179.234) by kwepemm600017.china.huawei.com (7.193.23.234) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 5 Sep 2023 14:57:33 +0800 Message-ID: <60f989f0-cfe2-61b5-5f5c-afe9584d8755@huawei.com> Date: Tue, 5 Sep 2023 14:57:32 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH v3] mm: memory-failure: use rcu lock instead of tasklist_lock when collect_procs() To: Andrew Morton CC: Matthew Wilcox , Naoya Horiguchi , "Wangkefeng (OS Kernel Lab)" , "Paul E . McKenney" , linmiaohe , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" References: <20230828022527.241693-1-tongtiangen@huawei.com> <20230903164122.fb7148f8004402a7552c3ec6@linux-foundation.org> From: Tong Tiangen In-Reply-To: <20230903164122.fb7148f8004402a7552c3ec6@linux-foundation.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.234] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemm600017.china.huawei.com (7.193.23.234) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: 981E0100015 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: q77tt94yu3897baghzj3oo8yt7mbh33c X-HE-Tag: 1693897061-926400 X-HE-Meta: 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 aBUbPvuj Sm11ftmEYVFqvy6SZCWctXJ/sJBekVT+bR7C+y50a9+kQfYovU6kJwwpjGOdyGvilcmDNx0mLFBVJApmOPWubK94MMvMfhYtXe3M06FlqolWCPS0/b0mg5DoAhiPjYdmxhZMp/51CVyIMX15VfUyHjbEXXIikd/7YYC3P0oHM3Gq6tmfcB2W2Az/BjvmdumDc7fzjpeHfWH6GMH1f0uNkISOVngCzLb+Vsi1zkNWqKipgRa1cQ3QBXhYk8h2dmdTcbJj55yxEdPZOs/nzD2eVGFTABX7bgp6kCDxlLUlLfPr8nIZzYekCb7JCK58ImfRYySncJf49vVchlQvfPloUaQXw/JTr+IRDmeMMIfh53Ka6XzVF9cebqNVwsogmJqFJp/XLcWiHW7Kye/gtNSL5LfAxiUn87SqFgBeGPBlClwzoUdETc/Mign4Zn835VSz5aeHo9E4VTQx1KZHlCu/N4Z9DpyZ40IKJSW9P 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: 在 2023/9/4 7:41, Andrew Morton 写道: > On Mon, 28 Aug 2023 10:25:27 +0800 Tong Tiangen wrote: > >> We found a softlock issue in our test, analyzed the logs, and found that >> the relevant CPU call trace as follows: >> >> ... >> >> By removing the use of tasklist_lock in task list iteration, we can break >> the softlock chain above. >> > > So I assume we'd like to backport this fix into -stable kernels? > > If so, are we able to identify a suitble Fixes: target? > . After checking the git logs of these functions, the lock-related code line is available when the functions are first introduced, as follows: copy_process(): kernel/fork.c commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (tag: v2.6.12-rc2) Author: Linus Torvalds Date: Sat Apr 16 15:20:36 2005 -0700 Linux-2.6.12-rc2 wp_page_copy(): mm/memory.c commit 2f38ab2c3c7fef04dca0313fd89d91f142ca9281 Author: Shachar Raindel Date: Tue Apr 14 15:46:32 2015 -0700 mm: refactor do_wp_page, extract the page copy flow pte_offset_map_lock: include/linux/mm.hq commit c74df32c724a1652ad8399b4891bb02c9d43743a Author: Hugh Dickins Date: Sat Oct 29 18:16:23 2005 -0700 [PATCH] mm: ptd_alloc take ptlock collect_procs_anon(): mm/memory-failure.c commit 6a46079cf57a7f7758e8b926980a4f852f89b34d Author: Andi Kleen Date: Wed Sep 16 11:50:15 2009 +0200 HWPOISON: The high level memory error handler in the VM v7 Is it appropriate to use the commit of the last introduction function(wp_page_copy())? Fixes: 2f38ab2c3c7f ("refactor do_wp_page, extract the page copy flow") Or use the commit introduced by the error reporting function(collect_procs_anon())? Fixes: 6a46079cf57a ("HWPOISON: The high level memory error handler in the VM v7")