From: "Srivatsa S. Bhat" Subject: Re: Deadlock on poweroff Date: Sun, 07 Oct 2012 22:35:01 +0530 Message-ID: <5071B63D.4020300@linux.vnet.ibm.com> References: <20121007024711.GA21403@shutemov.name> <20121007160311.GE2485@linux.vnet.ibm.com> <20121007165012.GA23535@shutemov.name> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Paul E. McKenney" , linux-kernel@vger.kernel.org, Dipankar Sarma , Thomas Gleixner , Andrew Morton , Steffen Klassert , linux-crypto@vger.kernel.org, "Srivatsa S. Bhat" To: "Kirill A. Shutemov" Return-path: Received: from e28smtp07.in.ibm.com ([122.248.162.7]:60689 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753Ab2JGRFw (ORCPT ); Sun, 7 Oct 2012 13:05:52 -0400 Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 7 Oct 2012 22:35:49 +0530 In-Reply-To: <20121007165012.GA23535@shutemov.name> Sender: linux-crypto-owner@vger.kernel.org List-ID: On 10/07/2012 10:20 PM, Kirill A. Shutemov wrote: > On Sun, Oct 07, 2012 at 09:03:11AM -0700, Paul E. McKenney wrote: >> On Sun, Oct 07, 2012 at 05:47:11AM +0300, Kirill A. Shutemov wrote: >>> Hi Paul and all, >>> >>> With commit 755609a9087fa983f567dc5452b2fa7b089b591f I've got deadlock on >>> poweroff. >>> >>> It guess it happens because of race for cpu_hotplug.lock: >>> >>> CPU A CPU B >>> disable_nonboot_cpus() >>> _cpu_down() >>> cpu_hotplug_begin() >>> mutex_lock(&cpu_hotplug.lock); >>> __cpu_notify() >>> padata_cpu_callback() >>> __padata_remove_cpu() >>> padata_replace() >>> synchronize_rcu() >>> rcu_gp_kthread() >>> get_online_cpus(); >>> mutex_lock(&cpu_hotplug.lock); >>> >>> Have you seen the issue before? >> >> This is a new one for me. Does the following (very lightly tested) >> patch help? > > Works for me. Thanks. > Could you share the patch please? Looks like it didn't hit the mailing lists.. Regards, Srivatsa S. Bhat