Re: [PATCH] Remove l_flushsema

David Chinner
2008-04-30T11:12:02Z

On Wed, Apr 30, 2008 at 06:58:32AM -0400, Christoph Hellwig wrote:
> On Wed, Apr 30, 2008 at 08:41:25PM +1000, David Chinner wrote:
> > The only thing that I'm concerned about here is that this will
> > substantially increase the time the l_icloglock is held. This is
> > a severely contended lock on large cpu count machines and putting
> > the wakeup inside this lock will increase the hold time.
> >
> > I guess I can address this by adding a new lock for the waitqueue
> > in a separate patch set.
>
> waitqueues are loked internally and don't need synchronization. With
> a little bit of re-arranging the code the wake_up could probably be
> moved out of the critical section.

Yeah, I just realised that myself and was about to reply as such....

I'll move the wakeup outside the lock.

Cheers,

Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group