Messages in this thread | | | Date | Mon, 26 Jul 2010 19:23:46 +0300 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH UPDATED 1/3] vhost: replace vhost_workqueue with per-vhost kthread |
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On Mon, Jul 26, 2010 at 06:05:27PM +0200, Tejun Heo wrote: > Hello, > > On 07/26/2010 05:50 PM, Michael S. Tsirkin wrote: > >> Hmmm... I'm not quite sure whether it's an optimization. I thought > >> the patch was due to feeling uncomfortable about using barriers? > > > > Oh yes. But getting rid of barriers is what motivated me originally. > > Yeah, getting rid of barriers is always good. :-) > > > Is there a git tree with kthread_worker applied? > > I might do this just for fun ... > > git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git for-next > > For the original implementaiton, please take a look at commit > b56c0d8937e665a27d90517ee7a746d0aa05af46. > > * Can you please keep the outer goto repeat loop? I just don't like > outermost for (;;).
Okay ... can we put the code in a {} scope to make it clear where does the loop starts and ends?
> * Placing try_to_freeze() could be a bit annoying. It shouldn't be > executed when there's a work to flush.
It currently seems to be executed when there is work to flush. Is this wrong?
> * I think A - B <= 0 test would be more familiar. At least > time_before/after() are implemented that way.
I am concerned that this overflows a signed integer - which I seem to remeber that C99 disallows. timer macros are on data path so might be worth the risk there, but flush is slow path so better be safe?
> Thanks. > > -- > tejun
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