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    SubjectRe: [PATCH][KVM][retry 4] Add support for Pause Filtering to AMD SVM
    Mark Langsdorf wrote:
    > This feature creates a new field in the VMCB called Pause
    > Filter Count. If Pause Filter Count is greater than 0 and
    > intercepting PAUSEs is enabled, the processor will increment
    > an internal counter when a PAUSE instruction occurs instead
    > of intercepting. When the internal counter reaches the
    > Pause Filter Count value, a PAUSE intercept will occur.
    > This feature can be used to detect contended spinlocks,
    > especially when the lock holding VCPU is not scheduled.
    > Rescheduling another VCPU prevents the VCPU seeking the
    > lock from wasting its quantum by spinning idly. Perform
    > the reschedule by increasing the the credited time on
    > the VCPU.
    > Experimental results show that most spinlocks are held
    > for less than 1000 PAUSE cycles or more than a few
    > thousand. Default the Pause Filter Counter to 3000 to
    > detect the contended spinlocks.
    > Processor support for this feature is indicated by a CPUID
    > bit.
    > On a 24 core system running 4 guests each with 16 VCPUs,
    > this patch improved overall performance of each guest's
    > 32 job kernbench by approximately 1%. Further performance
    > improvement may be possible with a more sophisticated
    > yield algorithm.

    Please split this into a scheduler patch and a kvm patch.

    error compiling committee.c: too many arguments to function

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      Last update: 2009-05-21 10:51    [W:0.022 / U:9.480 seconds]
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