On Fri, Oct 26 2001, Zlatko Calusic wrote:
> Linus Torvalds <torvalds@transmeta.com> writes:
>
> > On 25 Oct 2001, Zlatko Calusic wrote:
> > >
> > > Yes, I definitely have DMA turned ON. All parameters are OK. :)
> >
> > I suspect it may just be that "queue_nr_requests"/"batch_count" is
> > different in -ac: what happens if you tweak them to the same values?
> >
>
> Next test:
>
> block: 1024 slots per queue, batch=341
That's way too much, batch should just stay around 32, that is fine.
> Still very spiky, and during the write disk is uncapable of doing any
> reads. IOW, no serious application can be started before writing has
> finished. Shouldn't we favour reads over writes? Or is it just that
> the elevator is not doing its job right, so reads suffer?
You are probably just seeing starvation due to the very long queues.
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This archive was generated by hypermail 2b29 : Wed Oct 31 2001 - 21:00:30 EST