Re: [PATCH]cfq-iosched: don't take requests with long distence as close

From: Jeff Moyer
Date: Fri Jan 15 2010 - 14:46:05 EST


Corrado Zoccolo <czoccolo@xxxxxxxxx> writes:

> Hi Jeff,
> I think this patch has the same flaw as Shaohua's.
> The seekiness check that you introduce in cfq_rq_close is already
> present in its caller, cfq_close_cooperator, so it is not effective.

I don't think so. There are two queues, here. One queue is checked by
the caller, and that is the cur_cfqq. The __cfqq needs to also be
checked.

> Up to now, the only patch that improves this situation is the one that
> changes the unmerge policy to unmerge after a single time slice.

Yes, I definitely agree with that, and I think that patch should go in.

Cheers,
Jeff
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