From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH 0/11] Per-bdi writeback flusher threads v8 Date: Wed, 27 May 2009 20:14:03 +0200 Message-ID: <20090527181402.GP11363@kernel.dk> References: <1243417312-7444-1-git-send-email-jens.axboe@oracle.com> <20090527144754.GD10842@mit.edu> <20090527175353.GE10842@mit.edu> <20090527175830.GF10842@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, chris.mason@oracle.com, david@fromorbit.com, hch@infradead.org, akpm@linux-foundation.org, jack@suse.cz, yanmin_zhang@linux.intel.com, richard@rsk.demon.co.uk, damien.wyart@free.fr To: Theodore Tso Return-path: Received: from brick.kernel.dk ([93.163.65.50]:43156 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764084AbZE0SOB (ORCPT ); Wed, 27 May 2009 14:14:01 -0400 Content-Disposition: inline In-Reply-To: <20090527175830.GF10842@mit.edu> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, May 27 2009, Theodore Tso wrote: > On Wed, May 27, 2009 at 01:53:53PM -0400, Theodore Tso wrote: > > On Wed, May 27, 2009 at 10:47:54AM -0400, Theodore Tso wrote: > > > > > > I'll retry the test with your stock writeback-v8 git branch w/o any > > > ext4 patches planned the next mere window mainline to see if I get the > > > same soft lockup, but I thought I should give you an early heads up. > > > > Confirmed. I had to run fsstress twice, but I was able to trigger a > > soft hangup with just the per-bdi v8 patches using ext4. > > As you requested, here's the .config file which I used. This was on a > Lenovo S10 (N270 Atom dual-core CPU, 1.5 gigs of memory, 5400 rpm hdd). If you have time, can you rerun with this little patch? It moves the super sync to a separate thread. Thanks! diff --git a/mm/backing-dev.c b/mm/backing-dev.c index f71588c..8b30f29 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -218,10 +218,14 @@ static __init int bdi_class_init(void) } postcore_initcall(bdi_class_init); +static int bdi_sync_supers(void *unused); + static int __init default_bdi_init(void) { int err; + kthread_run(bdi_sync_supers, NULL, "bdi-super"); + err = bdi_init(&default_backing_dev_info); if (!err) bdi_register(&default_backing_dev_info, NULL, "default"); @@ -412,6 +416,20 @@ static void bdi_flush_io(struct backing_dev_info *bdi) generic_sync_bdi_inodes(NULL, &wbc); } +static int bdi_sync_supers(void *unused) +{ + while (!kthread_should_stop()) { + schedule_timeout(dirty_expire_interval * 10); + + /* + * Do this periodically, like kupdated() did before. + */ + sync_supers(); + } + + return 0; +} + static int bdi_forker_task(void *ptr) { struct bdi_writeback *me = ptr; @@ -424,11 +442,6 @@ static int bdi_forker_task(void *ptr) struct bdi_writeback *wb; /* - * Do this periodically, like kupdated() did before. - */ - sync_supers(); - - /* * Temporary measure, we want to make sure we don't see * dirty data on the default backing_dev_info */ -- Jens Axboe