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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,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 24FE6C433DF for ; Sun, 23 Aug 2020 03:43:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CD6072072D for ; Sun, 23 Aug 2020 03:43:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD6072072D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E0F086B0005; Sat, 22 Aug 2020 23:43:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DC08B6B0006; Sat, 22 Aug 2020 23:43:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CD56B6B0008; Sat, 22 Aug 2020 23:43:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0162.hostedemail.com [216.40.44.162]) by kanga.kvack.org (Postfix) with ESMTP id B333A6B0005 for ; Sat, 22 Aug 2020 23:43:44 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 70C5F362E for ; Sun, 23 Aug 2020 03:43:44 +0000 (UTC) X-FDA: 77180439168.25.bikes29_2f14e6127047 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id 379681804E3A0 for ; Sun, 23 Aug 2020 03:43:44 +0000 (UTC) X-HE-Tag: bikes29_2f14e6127047 X-Filterd-Recvd-Size: 3115 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Sun, 23 Aug 2020 03:43:42 +0000 (UTC) IronPort-SDR: D3dEizeDJH8yppZvXNOw9yeRbDBLDnEptHEQn3ngToy84dmyN8cLuMtwYwevb4mN4BXxE++NFZ Yfso+U9RZV5w== X-IronPort-AV: E=McAfee;i="6000,8403,9721"; a="143540960" X-IronPort-AV: E=Sophos;i="5.76,342,1592895600"; d="scan'208";a="143540960" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Aug 2020 20:43:41 -0700 IronPort-SDR: B3EZ2vOr4zYV58mEH9r1mGmK98K+VnqRorxAI7Y3XJd/rv3evm7mIyv4li2dE0XYUvqD+W4GmE bUpq9YZpG6RQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,342,1592895600"; d="scan'208";a="335670760" Received: from pl-dbox.sh.intel.com (HELO intel.com) ([10.239.159.39]) by FMSMGA003.fm.intel.com with ESMTP; 22 Aug 2020 20:43:40 -0700 Date: Sun, 23 Aug 2020 11:41:05 +0800 From: Philip Li To: Andrew Morton Cc: kernel test robot , Linux Memory Management List , Chinwen Chang Subject: Re: [linux-next:master] BUILD REGRESSION 605cbf3d5f20470ec303b79feda3202935f4a142 Message-ID: <20200823034105.GA2953@intel.com> References: <5f3edc64.qkHsk6Qli55TwDHw%lkp@intel.com> <20200820134305.baa5ac2c1300a6b412a0c7c9@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200820134305.baa5ac2c1300a6b412a0c7c9@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: 379681804E3A0 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 Thu, Aug 20, 2020 at 01:43:05PM -0700, Andrew Morton wrote: > On Fri, 21 Aug 2020 04:26:12 +0800 kernel test robot wrote: > > > tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > > branch HEAD: 605cbf3d5f20470ec303b79feda3202935f4a142 Add linux-next specific files for 20200820 > > > > Error/Warning in current branch: > > > ... > > > > > > fs/proc/task_mmu.c:947 show_smaps_rollup() error: double unlocked 'mm->mmap_lock' (orig line 879) > > This is code added by "mm: proc: smaps_rollup: do not stall write > attempts on mmap_lock" > (http://lkml.kernel.org/r/1597715898-3854-4-git-send-email-chinwen.chang@mediatek.com). > > I don't get it. Sorry Andrew, this is a false positive. We wrongly send out a few false reports related to "double unlocked" due to bot issue. Sorry for the inconvenience caused. > > : if (mmap_lock_is_contended(mm)) { > : mmap_read_unlock(mm); > : ret = mmap_read_lock_killable(mm); > : if (ret) { > : release_task_mempolicy(priv); > : goto out_put_mm; > : } > > Here the mmap_lock is again taken for read > > : ... > : > : } > : /* Case 2 above */ > : vma = vma->vm_next; > : } > : > : ... > : > : mmap_read_unlock(mm); > > and here it's unlocked. I don't see a possibility for double-unlock? >