Messages in this thread | | | Date | Wed, 14 Jan 2015 13:22:43 -0500 | From | Rik van Riel <> | Subject | Re: [patch -rt 1/2] KVM: use simple waitqueue for vcpu->wq |
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On 01/14/2015 12:12 PM, Marcelo Tosatti wrote: > The problem: > > On -RT, an emulated LAPIC timer instances has the following path: > > 1) hard interrupt > 2) ksoftirqd is scheduled > 3) ksoftirqd wakes up vcpu thread > 4) vcpu thread is scheduled > > This extra context switch introduces unnecessary latency in the > LAPIC path for a KVM guest.
> This patch reduces the average latency in my tests from 14us to 11us. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
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