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

[Richard Kennedy <richard@rsk.demon.co.uk>]

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.

regards
Richard