From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCHSET] block: per-queue policy activation, take#2 Date: Fri, 20 Apr 2012 10:17:42 -0700 Message-ID: <20120420171742.GC32324@google.com> References: <1334347895-6268-1-git-send-email-tj@kernel.org> <20120420080943.GG7505@kernel.dk> <4F91503D.2060402@kernel.dk> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=QWwDzg6qRfSMe14GP0MCUS6nOovx/qQROt4mH0UGj3g=; b=IngpYjFiLoiaoojAPCFuyeT2q0cuapZ2om0mwkduj7ttQyELxATMvANqps+NXdbDxS wGszyV+zemgKX7ixWBfO5qZN3+eJZXO0WofzkwAILfxIhkz2kGeCi67FqloBvPZN9PeO JhLxibKyw/37KTklEvD5KBVBUDTN59qgvf4dnrs7418yoJ26WdAp0dob+EOpfEpPXDf+ 4HnOEoE4FX4+ZTONSPf3Xqhdqbpd91abaz7CP1JGE3K9lHFJ28WAdcM06Ytp9H1FBxp7 DemnrT4+N8zYfS4x1s8QL/jnlYwgM64LgNoQNIjhYyzSSM4yryquXQybx3XFMRCDqq+8 1k+Q== Content-Disposition: inline In-Reply-To: <4F91503D.2060402-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jens Axboe Cc: vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, ctalbott-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, rni-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Hello, Jens. On Fri, Apr 20, 2012 at 02:02:05PM +0200, Jens Axboe wrote: > Tejun, everything merged in cleanly. A boot test didn't not go so well, > I'm afraid. It complains about stuck RCU. Even with extra RCU > debugging/info turned on, it doesn't give my any extra info. > > Config is attached. I can try and debug this on Monday, for now I've > pulled it out of for-next again. Hmmm... it works fine with the same config here (qemu w/ 4 cpus configured). Doesn't stuck RCU usually come from unbalanced RCU lock/unlocking? That should trigger context or RCU warnings before anything else, weird. Anyways, it would be great if you can provide more info on how to reproduce the problem. Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754776Ab2DTRRt (ORCPT ); Fri, 20 Apr 2012 13:17:49 -0400 Received: from mail-pz0-f52.google.com ([209.85.210.52]:44181 "EHLO mail-pz0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753310Ab2DTRRr (ORCPT ); Fri, 20 Apr 2012 13:17:47 -0400 Date: Fri, 20 Apr 2012 10:17:42 -0700 From: Tejun Heo To: Jens Axboe Cc: vgoyal@redhat.com, ctalbott@google.com, rni@google.com, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, containers@lists.linux-foundation.org Subject: Re: [PATCHSET] block: per-queue policy activation, take#2 Message-ID: <20120420171742.GC32324@google.com> References: <1334347895-6268-1-git-send-email-tj@kernel.org> <20120420080943.GG7505@kernel.dk> <4F91503D.2060402@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F91503D.2060402@kernel.dk> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Jens. On Fri, Apr 20, 2012 at 02:02:05PM +0200, Jens Axboe wrote: > Tejun, everything merged in cleanly. A boot test didn't not go so well, > I'm afraid. It complains about stuck RCU. Even with extra RCU > debugging/info turned on, it doesn't give my any extra info. > > Config is attached. I can try and debug this on Monday, for now I've > pulled it out of for-next again. Hmmm... it works fine with the same config here (qemu w/ 4 cpus configured). Doesn't stuck RCU usually come from unbalanced RCU lock/unlocking? That should trigger context or RCU warnings before anything else, weird. Anyways, it would be great if you can provide more info on how to reproduce the problem. Thanks. -- tejun