Re: [PATCH 2/2] KVM: x86: optimize delivery of TSC deadline timer interrupt

From: Marcelo Tosatti
Date: Tue Feb 10 2015 - 14:30:44 EST


On Sat, Feb 07, 2015 at 09:33:09PM +0100, Paolo Bonzini wrote:
> > Can remove another 300 cycles from do_div when programming LAPIC
> > tscdeadline timer.
>
> Do you mean using something like lib/reciprocal_div.c?

Yes.

> Good idea,
> though that's not latency, it's just being slow. :)

It adds to latency, yes (the guest will reprogram the
APIC timer before resuming userspace execution).

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