Re: [PATCH 0/11] Per-bdi writeback flusher threads v8

[Jens Axboe <jens.axboe@oracle.com>]

On Wed, May 27 2009, Richard Kennedy wrote:
> On Wed, 2009-05-27 at 11:41 +0200, Jens Axboe wrote:
> > Hi,
> > 
> > Here's the 8th version of the writeback patches. Changes since v7:
> > 
> > - Fold the "include default_backing_dev_info in writeback" patch into
> >   the core, we should just do it from the beginning.
> > - More series cleanup, I think it should be mostly complete now. No
> >   hunks are split between patches now (things like comments for
> >   functions added earlier, and so on).
> > - Fix hang with calling bdi_wait_on_work_clear() inside the bdi_lock
> >   mutex when the default wb thread had exited.
> > - Fix hang with queuing work on exited wb thread, it would have no
> >   receipients since the default wb thread wrongly cleared the bit
> >   from the register mask on exit. It must be persistent, which is
> >   why it gets initialized on bdi_register() already.
> > 
> > For ease of patching, I've put the full diff here:
> > 
> >   http://kernel.dk/writeback-v8.patch
> > 
> > and also stored this in a writeback-v7 branch that will not change,
> > you can pull that into Linus tree from here:
> > 
> >   git://git.kernel.dk/linux-2.6-block.git writeback-v8
> > 
> >  b/block/blk-core.c            |    1 
> >  b/drivers/block/aoe/aoeblk.c  |    1 
> >  b/drivers/char/mem.c          |    1 
> >  b/fs/btrfs/disk-io.c          |   24 -
> >  b/fs/buffer.c                 |    2 
> >  b/fs/char_dev.c               |    1 
> >  b/fs/configfs/inode.c         |    1 
> >  b/fs/fs-writeback.c           |  807 +++++++++++++++++++++++++++-------
> >  b/fs/fuse/inode.c             |    1 
> >  b/fs/hugetlbfs/inode.c        |    1 
> >  b/fs/nfs/client.c             |    1 
> >  b/fs/ntfs/super.c             |   33 -
> >  b/fs/ocfs2/dlm/dlmfs.c        |    1 
> >  b/fs/ramfs/inode.c            |    1 
> >  b/fs/super.c                  |    3 
> >  b/fs/sync.c                   |    2 
> >  b/fs/sysfs/inode.c            |    1 
> >  b/fs/ubifs/super.c            |    1 
> >  b/include/linux/backing-dev.h |   74 +++
> >  b/include/linux/fs.h          |   11 
> >  b/include/linux/writeback.h   |   15 
> >  b/kernel/cgroup.c             |    1 
> >  b/mm/Makefile                 |    2 
> >  b/mm/backing-dev.c            |  476 +++++++++++++++++++-
> >  b/mm/page-writeback.c         |  151 ------
> >  b/mm/swap_state.c             |    1 
> >  b/mm/vmscan.c                 |    2 
> >  mm/pdflush.c                  |  269 -----------
> >  28 files changed, 1248 insertions(+), 637 deletions(-)
> > 
> Hi Jens,
> 
> This is working nicely for me. It's successfully built a kernel with no
> problems at all, so you've fixed the earlier problem I had.
> 
> Early fio tests writing to 2 disks at the same time indicate that it's
> faster too. But there's a fair amount of variability so I will run more
> tests & see what the trend really is.

That's good to hear, thanks for testing! Do let me know if you run into
anything suspicious later on.

-- 
Jens Axboe