Re: IO scheduler based IO controller V10

From: Vivek Goyal
Date: Wed Sep 30 2009 - 16:27:31 EST


On Wed, Sep 30, 2009 at 10:05:39PM +0200, Mike Galbraith wrote:
>
>
> > /*
> > + * We may have seeky queues, don't throttle up just yet.
> > + */
> > + if (time_before(jiffies, cfqd->last_seeker + CIC_SEEK_THR))
> > + return 0;
> > +
>
> bzzzt. Window too large, but the though is to let them overload, but
> not instantly.
>

CIC_SEEK_THR is 8K jiffies so that would be 8seconds on 1000HZ system. Try
using one "slice_idle" period of 8 ms. But it might turn out to be too
short depending on the disk speed.

Thanks
Vivek
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