From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933605Ab1FWT7j (ORCPT ); Thu, 23 Jun 2011 15:59:39 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53012 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759408Ab1FWT7i (ORCPT ); Thu, 23 Jun 2011 15:59:38 -0400 Date: Thu, 23 Jun 2011 21:59:23 +0200 From: Jan Kara To: Peter Zijlstra Cc: Valdis.Kletnieks@vt.edu, Jan Kara , stable@kernel.org, Andrew Morton , Thomas Gleixner , Jeff Garzik , IngIngo Molnar , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Subject: Re: mmotm 2011-06-22 - inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. Message-ID: <20110623195923.GA14337@quack.suse.cz> References: <201106222042.p5MKgiEe025352@imap1.linux-foundation.org> <6189.1308794391@turing-police.cc.vt.edu> <1308843516.1022.139.camel@twins> <47718.1308844931@turing-police.cc.vt.edu> <1308845285.1022.143.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1308845285.1022.143.camel@twins> 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 On Thu 23-06-11 18:08:05, Peter Zijlstra wrote: > On Thu, 2011-06-23 at 12:02 -0400, Valdis.Kletnieks@vt.edu wrote: > > On Thu, 23 Jun 2011 17:38:36 +0200, Peter Zijlstra said: > > > On Wed, 2011-06-22 at 21:59 -0400, Valdis.Kletnieks@vt.edu wrote: > > > > [ 20.254275] {SOFTIRQ-ON-W} state was registered at: > > > > [ 20.254275] [] mark_irqflags+0xf2/0x13e > > > > [ 20.254275] [] __lock_acquire+0x22b/0x3e2 > > > > [ 20.254275] [] lock_acquire+0x103/0x153 > > > > [ 20.254275] [] _raw_spin_lock+0x36/0x45 > > > > [ 20.254275] [] end_writeback+0x33/0x103 > > > > [ 20.254275] [] bdev_evict_inode+0x3e/0xbe > > > > [ 20.254275] [] evict+0xb0/0x173 > > > > [ 20.254275] [] iput_final+0x171/0x17a > > > > [ 20.254275] [] iput+0x4e/0x53 > > > > [ 20.254275] [] __blkdev_put+0x1c0/0x1eb > > > > [ 20.254275] [] blkdev_put+0x1e6/0x1f5 > > > > [ 20.254275] [] register_disk+0xea/0x13c > > > > [ 20.254275] [] add_disk+0x12f/0x1a4 > > > > [ 20.254275] [] sd_probe_async+0x115/0x1b5 > > > > [ 20.254275] [] async_run_entry_fn+0x99/0x12a > > > > [ 20.254275] [] process_one_work+0x25d/0x467 > > > > [ 20.254275] [] worker_thread+0x152/0x206 > > > > [ 20.254275] [] kthread+0x7f/0x87 > > > > [ 20.254275] [] kernel_thread_helper+0x4/0x10=20 > > > > > > That looks broken. Not having -mm, is there a git tree some place?, I > > > cannot quite see how end_writeback() is taking mapping->tree_lock as my > > > version looks like: > > > > > > void end_writeback(struct inode *inode) > > > { > > > might_sleep(); > > > BUG_ON(inode->i_data.nrpages); > > > BUG_ON(!list_empty(&inode->i_data.private_list)); > > > > mm-fix-assertion-mapping-nrpages-==-0-in-end_writeback.patch does this: > > > > diff -puN fs/inode.c~mm-fix-assertion-mapping-nrpages-==-0-in-end_writeback fs/inode.c > > --- a/fs/inode.c~mm-fix-assertion-mapping-nrpages-==-0-in-end_writeback > > +++ a/fs/inode.c > > @@ -423,7 +423,14 @@ EXPORT_SYMBOL(remove_inode_hash); > > void end_writeback(struct inode *inode) > > { > > might_sleep(); > > + /* > > + * We have to cycle tree_lock here because reclaim can be still in the > > + * process of removing the last page (in __delete_from_page_cache()) > > + * and we must not free mapping under it. > > + */ > > + spin_lock(&inode->i_data.tree_lock); > > BUG_ON(inode->i_data.nrpages); > > + spin_unlock(&inode->i_data.tree_lock); > > BUG_ON(!list_empty(&inode->i_data.private_list)); > > BUG_ON(!(inode->i_state & I_FREEING)); > > BUG_ON(inode->i_state & I_CLEAR); > > > > Adding Jan Kara to the list, and stable@kernel.org because the patch was cc'ed to there... > > Yep, that very much wants to be spin_{un,}lock_irq(). Oh, right. Stupid me. I'll fix that. Thanks for debugging this. Honza -- Jan Kara SUSE Labs, CR