Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755163AbYJCEpc (ORCPT ); Fri, 3 Oct 2008 00:45:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751523AbYJCEpY (ORCPT ); Fri, 3 Oct 2008 00:45:24 -0400 Received: from casper.infradead.org ([85.118.1.10]:38261 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751403AbYJCEpX (ORCPT ); Fri, 3 Oct 2008 00:45:23 -0400 Date: Thu, 2 Oct 2008 21:45:11 -0700 From: Arjan van de Ven To: Andrew Morton Cc: Jens Axboe , linux-kernel@vger.kernel.org, Alan Cox Subject: Re: [PATCH] Give kjournald a IOPRIO_CLASS_RT io priority Message-ID: <20081002214511.3a567c2d@infradead.org> In-Reply-To: <20081002214000.89420bb3.akpm@linux-foundation.org> References: <20081001200034.65eb67d6@infradead.org> <20081001215638.3a65134c.akpm@linux-foundation.org> <20081002062736.GR19428@kernel.dk> <20081001235501.2b7f50fe.akpm@linux-foundation.org> <20081002061236.3c71c877@infradead.org> <20081002132457.46ad8d05.akpm@linux-foundation.org> <20081002210117.0f5062f7@infradead.org> <20081002212355.621a4fb6@infradead.org> <20081002214000.89420bb3.akpm@linux-foundation.org> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2335 Lines: 58 On Thu, 2 Oct 2008 21:40:00 -0700 Andrew Morton wrote: > On Thu, 2 Oct 2008 21:23:55 -0700 Arjan van de Ven > wrote: > > > On Thu, 2 Oct 2008 21:01:17 -0700 > > Arjan van de Ven wrote: > > > > > > _ > > > > > > > > perhaps for varying values of "1". > > > > > > > caught a few, a few were over 3 1/2 seconds in stall time > > (specifically I know this for the last one) > > > > (I've stripped out the ? entries to keep them reasonable) > > > > [ 410.168277] WARNING: at kernel/sched.c:5652 > > io_schedule+0x77/0xb0() [ 410.168347] Pid: 699, comm: kjournald > > Not tainted 2.6.27-rc8-tip #50 [ 410.168366] [] > > warn_on_slowpath+0x41/0x65 [ 410.168414] [] > > io_schedule+0x77/0xb0 [ 410.168421] [] > > sync_buffer+0x33/0x37 [ 410.168429] [] > > __wait_on_bit+0x36/0x5d [ 410.168445] [] > > out_of_line_wait_on_bit+0xab/0xb3 [ 410.168471] [] > > __wait_on_buffer+0x19/0x1c [ 410.168478] [] > > journal_commit_transaction+0x484/0xcb2 [ 410.168519] [] > > kjournald+0xc7/0x1ea [ 410.168544] [] kthread+0x3b/0x61 > > [ 410.168559] [] kernel_thread_helper+0x7/0x10 > > [ 410.168567] ======================= > > [ 410.168572] ---[ end trace de523043f88bd9a7 ]--- > > [ 451.605034] ------------[ cut here ]------------ > > [ 451.605041] WARNING: at kernel/sched.c:5652 > > io_schedule+0x77/0xb0() [ 451.605114] Pid: 699, comm: kjournald > > Tainted: G W 2.6.27-rc8-tip #50 > > > > ... > > > > hm, they're all kjournald getting stuck on lock_buffer(). That _may_ > be related to the one we care about, but it doesn't seem likely. one of them is (based on timestamps of the printk) is less than 3 seconds before the "real" one, while the real one's delay was 4 seconds. To me that implies they're at least somewhat correlated... -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/