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Re: [Xen-devel] [PATCH 0/2] Improve hpet accuracy

To: Dave Winchell <dwinchell@xxxxxxxxxxxxxxx>, <dan.magenheimer@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH 0/2] Improve hpet accuracy
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 10 Jun 2008 13:42:18 +0100
Cc: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Ben Guthro <bguthro@xxxxxxxxxxxxxxx>
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On 10/6/08 13:34, "Dave Winchell" <dwinchell@xxxxxxxxxxxxxxx> wrote:

> Yes, the rate ends up being about half the normal rate because
> I toss the interrupt if it doesn't meet the requirement. If, in testing, we find
> a guest that has a problem with half the normal rate, we can fine tune
> the policy. For example, instead of discarding set a small timer.

A better solution is to set the new period timer at end-of-interrupt time
(in the callback) instead of delivery time (timer expiration time).
This way the rate will be very close to what the guest expects.
I think I'll make this change.

Yes, that’s what I thought you’d done. It sounds nicer to me.

 -- Keir
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