From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965662AbXCVES2 (ORCPT ); Thu, 22 Mar 2007 00:18:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965671AbXCVES2 (ORCPT ); Thu, 22 Mar 2007 00:18:28 -0400 Received: from smtp102.mail.mud.yahoo.com ([209.191.85.212]:35035 "HELO smtp102.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S965662AbXCVES1 (ORCPT ); Thu, 22 Mar 2007 00:18:27 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=SC7u44hQFZE+xgtPgXbf9U+KCMv6ZK45Haxjnk+vV8z8h1chUfB5lPLyrelimhPrEtGWw0nyUoQEBKOX5FVU84G8+A6sPB5L1g+ae5nhdkboUplBE9eArPQXo/cuG3XdC+K4KNsuapiPhVRJOieE5SMBzaVNLShwsaDJr8WwIC4= ; X-YMail-OSG: TY8qW9YVM1lydosK_imRKJacUk9ibeDhbzOOuJZka58gtI0LSb06kFXaeRhpnFROEt.kKJD9FRXOcLNxEBNwwVe.m2UnhGE5555WG8c.Svjp1QJlv4zU2cxGPVNKCDit Message-ID: <46020385.50301@yahoo.com.au> Date: Thu, 22 Mar 2007 15:18:13 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Linus Torvalds CC: Adrian Bunk , Andrew Morton , Linux Kernel Mailing List , Michal Piotrowski , Mariusz Kozlowski , Oliver Pinter , Sid Boyce , Nick Piggin , Jens Axboe Subject: Re: [1/6] 2.6.21-rc4: known regressions References: <20070318184908.GU752@stusta.de> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > In contrast, the hang reported by Mariusz Kozlowski has a slightly > different feel to it, but there's a tantalizing pattern in there too: > > http://www.ussg.iu.edu/hypermail/linux/kernel/0703.0/1243.html > > Call Trace: > [] io_schedule+0x42/0x59 > [] sleep_on_buffer+0x8/0xc > [] __wait_on_bit+0x47/0x6c > [] out_of_line_wait_on_bit+0x5b/0x64 > [] __wait_on_buffer+0x27/0x2d > [] journal_commit_transaction+0x707/0x127f > [] kjournald+0xac/0x1ed > [] kthread+0xa2/0xc9 > [] kernel_thread_helper+0x7/0x1c > > which certainly also looks like an IO never completed (or completed but > never woke anything up). > > It also seems to be related to *buffers*. Maybe the whole bh layer thing > is a fluke, but it's not waiting for normal data, it's very much waiting > for those journal things that all use buffer heads.Which just makes me > worry about those patches by Nick (which did come in through Andrew). I > don't think it's the memorder one (it looks safe and shouldn't matter on > x86 anyway!), but what about the > > fs: fix __block_write_full_page error case buffer submission > > locking change for example? Or that "fs: fix nobh data leak" thing with > its fix? It uses "SetPageUptodate(page);" without waking up anybody who > might wait for it (but the waiters here seem to wait on buffers, so that's > probably not it).. Nothing sleeps on PageUptodate, so I don't think that could explain it. The fs: fix __block_write_full_page error case buffer submission patch does change the locking, but I'd be really suprised if that was the problem, because it changes locking to match the regular non-error path submission. It could be possible that ext3 is doing something weird and expecting the old behaviour if it failed get_block, but that seems pretty weird to do, and would need fixing. fs: nobh data leak... again hard to see how it could cause an unlock/wakeup to get lost. Is Mariusz using the nobh mount option? It wouldn't hurt to test with these patches backed out... > Alternatively, maybe it really is an _io_ problem (and the buffer-head > thing is just a red herring, and it could happen to other IO, it's just > that metadata IO uses buffer heads), and it's the scheduler changes since > 2.6.20.. I see what you mean. Could it be an ext3 or jbd change I wonder? -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com