Messages in this thread | | | From | Daniel Phillips <> | Subject | Re: [1/1] Block device throttling [Re: Distributed storage.] | Date | Mon, 27 Aug 2007 14:57:37 -0700 |
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Say Evgeniy, something I was curious about but forgot to ask you earlier...
On Wednesday 08 August 2007 03:17, Evgeniy Polyakov wrote: > ...All oerations are not atomic, since we do not care about precise > number of bios, but a fact, that we are close or close enough to the > limit. > ... in bio->endio > + q->bio_queued--;
In your proposed patch, what prevents the race:
cpu1 cpu2
read q->bio_queued q->bio_queued-- write q->bio_queued - 1 Whoops! We leaked a throttle count.
Regards,
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