From: Chris Mason <chris.mason@oracle.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <jens.axboe@oracle.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
david@fromorbit.com, npiggin@suse.de, linux-mm@kvack.org
Subject: Re: [PATCH 2/7] writeback: switch to per-bdi threads for flushing data
Date: Mon, 16 Mar 2009 09:30:14 -0400 [thread overview]
Message-ID: <1237210214.30224.3.camel@think.oraclecorp.com> (raw)
In-Reply-To: <20090316102253.GB9510@infradead.org>
On Mon, 2009-03-16 at 06:22 -0400, Christoph Hellwig wrote:
> On Thu, Mar 12, 2009 at 03:33:43PM +0100, Jens Axboe wrote:
> > +static void bdi_kupdated(struct backing_dev_info *bdi)
> > +{
> > + long nr_to_write;
> > + struct writeback_control wbc = {
> > + .bdi = bdi,
> > + .sync_mode = WB_SYNC_NONE,
> > + .nr_to_write = 0,
> > + .for_kupdate = 1,
> > + .range_cyclic = 1,
> > + };
> > +
> > + sync_supers();
>
> Not directly related to your patch, but can someone explain WTF
> sync_supers is doing here or in the old kupdated? We're writing back
> dirty pages from the VM, and for some reason we try to also write back
> superblocks. This doesn't really make any sense.
Some of our poor filesystem cousins don't write the super until kupdate
kicks them (see ext2_write_super). kupdate has always been the periodic
FS thread of last resort.
-chris
WARNING: multiple messages have this Message-ID (diff)
From: Chris Mason <chris.mason@oracle.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <jens.axboe@oracle.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
david@fromorbit.com, npiggin@suse.de, linux-mm@kvack.org
Subject: Re: [PATCH 2/7] writeback: switch to per-bdi threads for flushing data
Date: Mon, 16 Mar 2009 09:30:14 -0400 [thread overview]
Message-ID: <1237210214.30224.3.camel@think.oraclecorp.com> (raw)
In-Reply-To: <20090316102253.GB9510@infradead.org>
On Mon, 2009-03-16 at 06:22 -0400, Christoph Hellwig wrote:
> On Thu, Mar 12, 2009 at 03:33:43PM +0100, Jens Axboe wrote:
> > +static void bdi_kupdated(struct backing_dev_info *bdi)
> > +{
> > + long nr_to_write;
> > + struct writeback_control wbc = {
> > + .bdi = bdi,
> > + .sync_mode = WB_SYNC_NONE,
> > + .nr_to_write = 0,
> > + .for_kupdate = 1,
> > + .range_cyclic = 1,
> > + };
> > +
> > + sync_supers();
>
> Not directly related to your patch, but can someone explain WTF
> sync_supers is doing here or in the old kupdated? We're writing back
> dirty pages from the VM, and for some reason we try to also write back
> superblocks. This doesn't really make any sense.
Some of our poor filesystem cousins don't write the super until kupdate
kicks them (see ext2_write_super). kupdate has always been the periodic
FS thread of last resort.
-chris
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next prev parent reply other threads:[~2009-03-16 13:31 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-12 14:33 [PATCH 0/7] Per-bdi writeback flusher threads Jens Axboe
2009-03-12 14:33 ` [PATCH 1/7] writeback: move dirty inodes from super_block to backing_dev_info Jens Axboe
2009-03-24 16:17 ` Jan Kara
2009-03-24 18:45 ` Jens Axboe
2009-03-12 14:33 ` [PATCH 2/7] writeback: switch to per-bdi threads for flushing data Jens Axboe
2009-03-13 5:33 ` Andrew Morton
2009-03-13 10:54 ` Jens Axboe
2009-03-15 22:52 ` Dave Chinner
2009-03-16 7:33 ` Jens Axboe
2009-03-16 10:17 ` Christoph Hellwig
2009-03-16 10:21 ` Jens Axboe
2009-03-16 23:38 ` Dave Chinner
2009-03-17 9:37 ` Jens Axboe
2009-03-17 13:21 ` Chris Mason
2009-03-16 10:22 ` Christoph Hellwig
2009-03-16 10:22 ` Christoph Hellwig
2009-03-16 13:30 ` Chris Mason [this message]
2009-03-16 13:30 ` Chris Mason
2009-03-16 13:39 ` Christoph Hellwig
2009-03-16 13:39 ` Christoph Hellwig
2009-03-12 14:33 ` [PATCH 3/7] writeback: get rid of pdflush_operation() in emergency sync and remount Jens Axboe
2009-03-16 10:13 ` Christoph Hellwig
2009-03-12 14:33 ` [PATCH 4/7] writeback: get rid of task/current_is_pdflush() Jens Axboe
2009-03-16 10:14 ` Christoph Hellwig
2009-03-16 10:22 ` Jens Axboe
2009-03-16 13:26 ` Chris Mason
2009-03-12 14:33 ` [PATCH 5/7] writeback: move the default backing_dev_info out of readahead Jens Axboe
2009-03-16 10:19 ` Christoph Hellwig
2009-03-16 10:23 ` Jens Axboe
2009-03-12 14:33 ` [PATCH 6/7] writeback: add lazy bdi->task creation Jens Axboe
2009-03-12 14:33 ` [PATCH 7/7] writeback: add some debug inode list counters to bdi stats Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2009-08-31 19:41 [PATCH 0/7] Per-bdi writeback flusher threads v15 Jens Axboe
2009-08-31 19:41 ` [PATCH 2/7] writeback: switch to per-bdi threads for flushing data Jens Axboe
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