Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757186Ab0FIJd2 (ORCPT ); Wed, 9 Jun 2010 05:33:28 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:49264 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756262Ab0FIJdZ (ORCPT ); Wed, 9 Jun 2010 05:33:25 -0400 Date: Wed, 9 Jun 2010 11:32:49 +0200 From: Ingo Molnar To: Jens Axboe Cc: Linus Torvalds , "Rafael J. Wysocki" , Carl Worth , Eric Anholt , Venkatesh Pallipadi , Dave Airlie , Jesse Barnes , David H?rdeman , Mauro Carvalho Chehab , Eric Dumazet , Linux Kernel Mailing List , Maciej Rutecki , Andrew Morton , Kernel Testers List , Network Development , Linux ACPI , Linux PM List , Linux SCSI List , Linux Wireless List , DRI Subject: Re: 2.6.35-rc2-git2: Reported regressions from 2.6.34 Message-ID: <20100609093249.GA17026@elte.hu> References:

<4C0F4872.7090909@fusionio.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C0F4872.7090909@fusionio.com> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2859 Lines: 71 * Jens Axboe wrote: > On 2010-06-09 03:53, Linus Torvalds wrote: > >> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=16129 > >> Subject : BUG: using smp_processor_id() in preemptible [00000000] code: jbd2/sda2 > >> Submitter : Jan Kreuzer > >> Date : 2010-06-05 06:15 (4 days old) > > > > This seems to have been introduced by > > > > commit 7cbaef9c83e58bbd4bdd534b09052b6c5ec457d5 > > Author: Ingo Molnar > > Date: Sat Nov 8 17:05:38 2008 +0100 > > > > sched: optimize sched_clock() a bit > > > > sched_clock() uses cycles_2_ns() needlessly - which is an irq-disabling > > variant of __cycles_2_ns(). > > > > Most of the time sched_clock() is called with irqs disabled already. > > The few places that call it with irqs enabled need to be updated. > > > > Signed-off-by: Ingo Molnar > > > > and this seems to be one of those calling cases that need to be updated. > > > > Ingo? The call trace is: > > > > BUG: using smp_processor_id() in preemptible [00000000] code: jbd2/sda2-8/337 > > caller is native_sched_clock+0x3c/0x68 > > Pid: 337, comm: jbd2/sda2-8 Not tainted 2.6.35-rc1jan+ #4 > > Call Trace: > > [] debug_smp_processor_id+0xc9/0xe4 > > [] native_sched_clock+0x3c/0x68 > > [] sched_clock+0x9/0xd > > [] blk_rq_init+0x97/0xa3 > > [] get_request+0x1c4/0x2d0 > > [] get_request_wait+0x29/0x1a6 > > [] __make_request+0x338/0x45b > > [] generic_make_request+0x2bb/0x330 > > [] submit_bio+0xd2/0xef > > [] submit_bh+0xf4/0x116 > > [] block_write_full_page_endio+0x89/0x96 > > [] block_write_full_page+0x15/0x17 > > [] ext4_writepage+0x356/0x36b > > [] __writepage+0x1a/0x39 > > [] write_cache_pages+0x20d/0x346 > > [] generic_writepages+0x27/0x29 > > [] journal_submit_data_buffers+0x110/0x17d > > [] jbd2_journal_commit_transaction+0x4cb/0x156d > > [] kjournald2+0x147/0x37a > > > > (from the bugzilla thing) > > This should be fixed by commit 28f4197e which was merged on friday. The scheduler commit adding local_clock() (for .36) is: c676329: sched_clock: Add local_clock() API and improve documentation So once that is upstream the block IO statistics code can use that. Thanks, Ingo -- 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/