From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1516638654; cv=none; d=google.com; s=arc-20160816; b=znTO8B9MLUcjAR4c5l9qZfjhtFr0XcHFMbHa6k1MufSgljdfiSNZltDFBJQ3dnhNdU 1CiVK0V/qMvOxiUiLcjguYGRitdeCp8yBSIyLPGmjYAgad/Xw2gy54geZJKcUh9MiSKm bYEi0emKMLym6MuaaYNNKX1f8ovP3sqrDZUwjt7CfL15V+uNqgepO+soxwsgqp0/H4J/ hdKwoynBnrk34YFh54+6LS81wubZsipUlin8V4NMBofUNETD6olBLk0gK57/pvQPNjnc DNxluyo3kim4hC/WJGDmsySdyyPJCLvRSesEmdVCfMB0/o89HRCvadi7WdJ8AVolDWtB d2tw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:sender:dkim-signature :arc-authentication-results; bh=oYFc+ceErf/YRESCtowUZvp7/9HwSJyys8Cd1yqhJr0=; b=erZ0+Zh2GoMd/wmzSUBav2P6G4xTcBokJnadKpUV6ILqTfhtgWepDtWaW5wuNyB53c G//8tQL9f/dFz/jJAIqJu0bokCcQbLImF+uOendC7Zdc1JDMRxV9uH/H9EVpYM8qgTNs eRAkLd5KZOesX25Ed+nvCbwGDJRXeqWjw7X1Kn22DzkqdXpugQUGKOhG9Z2q1VrF1qAv /6iDqmbtbyPhIIsDos3NyME4E1NHq2BPyQDR0BZRGejkALWe4E5uG5EYWt2bbcAmrVNw TjNO8Sj+rYQe14sTmm0uaXbbNbzpbrCrTnXqJOr5YKnTLAQ8tRnF2r5J2h8+beD569M+ fLIw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=AGDa2Cpg; spf=pass (google.com: domain of htejun@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=htejun@gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=AGDa2Cpg; spf=pass (google.com: domain of htejun@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=htejun@gmail.com X-Google-Smtp-Source: AH8x225CWlGfFBnVxp4hzM2vE8hRoK2TnVeXgGliLZ2+r+hblso5ChNw6YlIpMQcfdheUQc6vh3G6g== Sender: Tejun Heo Date: Mon, 22 Jan 2018 08:30:51 -0800 From: Tejun Heo To: Steven Rostedt Cc: LKML , Johannes Weiner , Li Zefan , cgroups@vger.kernel.org, Greg Kroah-Hartman Subject: Re: [BUG] cgroup lockup while upgrading udev on debian Message-ID: <20180122163051.GE1096857@devbig577.frc2.facebook.com> References: <20180121213108.4218693b@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180121213108.4218693b@gandalf.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590258076360413390?= X-GMAIL-MSGID: =?utf-8?q?1590310893478091112?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Hello, Steven. On Sun, Jan 21, 2018 at 09:31:08PM -0500, Steven Rostedt wrote: > While upgrading my system, it locked up while upgrading udev. It locked > up on vanilla v4.14.12, and it also locked up on debian's 4.14 kernel > as well. When I booted debian's 4.9 kernel, it upgraded fine. > > Note, this is my main server and not a development box. It is not > something I'm going to run bisects or other tests on. I don't even have > it logging to serial console (hence the photo). It's serials are hooked > to my test boxes. That is, it receives logs, it's not set up to send > them. > > Attached in the photo of the crash that happened when I did: > > # dpkg --configure udev It looks like the same bug which was fixed by 74d0833c659a ("cgroup: fix css_task_iter crash on CSS_TASK_ITER_PROC"). The bug got introduced durinv v4.14 cycle and triggers when cgroup1 and cgroup2 are used at the same time, which the recent versions of systemd does when in cgroup1 mode. Thanks. -- tejun