Re: [PATCH RFC V5 0/3] kvm: Improving directed yield in PLE handler
From: Avi Kivity
Date: Mon Jul 23 2012 - 06:03:42 EST
On 07/18/2012 04:37 PM, Raghavendra K T wrote:
> Currently Pause Loop Exit (PLE) handler is doing directed yield to a
> random vcpu on pl-exit. We already have filtering while choosing
> the candidate to yield_to. This change adds more checks while choosing
> a candidate to yield_to.
> On a large vcpu guests, there is a high probability of
> yielding to the same vcpu who had recently done a pause-loop exit.
> Such a yield can lead to the vcpu spinning again.
> The patchset keeps track of the pause loop exit and gives chance to a
> vcpu which has:
> (a) Not done pause loop exit at all (probably he is preempted lock-holder)
> (b) vcpu skipped in last iteration because it did pause loop exit, and
> probably has become eligible now (next eligible lock holder)
> This concept also helps in cpu relax interception cases which use same handler.
Thanks, applied to 'queue'.
error compiling committee.c: too many arguments to function
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