Re: [PATCH 0/11] Per-bdi writeback flusher threads v9

From: Artem Bityutskiy
Date: Wed Jun 03 2009 - 04:12:02 EST


ext Jens Axboe wrote:
On Fri, May 29 2009, Artem Bityutskiy wrote:
Artem Bityutskiy wrote:
Jens Axboe wrote:
Hi,

Here's the 9th version of the writeback patches. Changes since v8:

- Fix a bdi_work on-stack allocation hang. I hope this fixes Ted's
issue.
- Get rid of the explicit wait queues, we can just use wake_up_process()
since it's just for that one task.
- Add separate "sync_supers" thread that makes sure that the dirty
super blocks get written. We cannot safely do this from
bdi_forker_task(),
as that risks deadlocking on ->s_umount. Artem, I implemented this
by doing the wake ups from a timer so that it would be easier for you
to just deactivate the timer when there are no super blocks.

For ease of patching, I've put the full diff here:

http://kernel.dk/writeback-v9.patch

and also stored this in a writeback-v9 branch that will not change,
you can pull that into Linus tree from here:

git://git.kernel.dk/linux-2.6-block.git writeback-v9
I'm working with the above branch. Got the following twice.
Not sure what triggers this, probably if I do nothing and
cpufreq starts doing its magic, this is triggered.

And I'm not sure it has something to do with your changes,
it is just that I saw this only with your tree. Please,
ignore if this is not relevant.
Sorry, probably I shouldn't have reported this before looking
closer. I'll investigate this later and fine out whether it
is related to your work or not. Sorry for too early and probably
false alarm.

No problem. If it does turn out to have some relation to the writeback
stuff, let me know.

OK, I'm confirming that I observe this also with pure 2.6.30-rc7
as well.


--
Best Regards,
Artem Bityutskiy (ÐÑÑÑÐ ÐÐÑÑÑÐÐÐ)
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