Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756858Ab1CaDel (ORCPT ); Wed, 30 Mar 2011 23:34:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:19125 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753568Ab1CaDek (ORCPT ); Wed, 30 Mar 2011 23:34:40 -0400 Date: Wed, 30 Mar 2011 23:34:33 -0400 From: Dave Jones To: Linus Torvalds , Andrew Morton , Linux Kernel Subject: Re: excessive kworker activity when idle. (was Re: vma corruption in today's -git) Message-ID: <20110331033432.GA434@redhat.com> Mail-Followup-To: Dave Jones , Linus Torvalds , Andrew Morton , Linux Kernel References: <20110329040939.GA32764@redhat.com> <20110331030917.GB26057@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110331030917.GB26057@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1132 Lines: 27 On Wed, Mar 30, 2011 at 11:09:18PM -0400, Dave Jones wrote: > I can still reproduce the problem where kworker threads go nutso > when the machine should be completely idle. > > top shows two kworker threads constantly at >80% cpu. > > I can now profile it with perf though, so I'll dig deeper. > I need to try a build with slab debug etc turned off, just to be sure that > isn't throwing things into a spin. so 'perf kmem record sleep 5' shows hundreds of calls kmem_cache_free from the kworker processes. Called from shmem_i_callback, __d_free and file_free_rcu. My guess is that my fuzzing caused so many allocations that the rcu freeing is still ongoing an hour or so after the process has quit. does that make any sense? Although if that hypothesis is true, shouldn't I be able to observe this by watching slabtop ? because I don't see anything decreasing... Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/