Re: [RFC v2] ext4: Don't send extra barrier during fsync if thereare no dirty pages.

From: Darrick J. Wong
Date: Fri Aug 06 2010 - 03:04:33 EST


On Thu, Aug 05, 2010 at 12:45:04PM -0400, Ted Ts'o wrote:
> P.S. If it wasn't clear, I'm still in favor of trying to coordinate
> barriers across the whole file system, since that is much more likely
> to help use cases that arise in real life.

Ok. I have a rough sketch of a patch to do that, and I was going to send it
out today, but the test machine caught on fire while I was hammering it with
the fsync tests one last time and ... yeah. I'm fairly sure the patch didn't
cause the fire, but I'll check anyway after I finish cleaning up.

"[PATCH] ext4: Don't set my machine ablaze with barrier requests" :P

(The patch did seem to cut barrier requests counts by about 20% though the
impact on performance was pretty small.)

--D
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