Re: [PATCH v4 0/8] KVM paravirt remote flush tlb

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On 09/04/2012 04:30 AM, Nikunj A Dadhania wrote:
> On Mon, 03 Sep 2012 17:33:46 +0300, Avi Kivity <avi@xxxxxxxxxx> wrote:
>> On 08/21/2012 02:25 PM, Nikunj A. Dadhania wrote:
>> > 
>> > kernbench(lower is better)
>> > ==========================
>> >          base      pvflushv4      %improvement
>> > 1VM    48.5800       46.8513       3.55846
>> > 2VM   108.1823      104.6410       3.27346
>> > 3VM   183.2733      163.3547      10.86825
>> > 
>> > ebizzy(higher is better)
>> > ========================
>> >          base         pvflushv4      %improvement
>> > 1VM     2414.5000     2089.8750     -13.44481
>> > 2VM     2167.6250     2371.7500      9.41699
>> > 3VM     1600.1111     2102.5556     31.40060
>> > 
>> 
>> The regression is worrying.  We're improving the contended case at the
>> cost of the non-contended case, this is usually the wrong thing to do.
>> Do we have any clear idea of the cause of the regression?
>> 
> Previous perf numbers suggest that in 1VM scenario flush_tlb_others_ipi
> is around 2%, while for contented case its around 10%. That is what is
> helping contended case.

But what is causing the regression for the uncontended case?

-- 
error compiling committee.c: too many arguments to function
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