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    SubjectRe: [PATCH 08/11] perf tool: precise mode requires exclude_guest
    Hi Peter:

    On 7/25/12 11:50 PM, Gleb Natapov wrote:
    > On Wed, Jul 25, 2012 at 10:35:46PM +0200, Peter Zijlstra wrote:
    >> On Tue, 2012-07-24 at 18:15 +0200, Robert Richter wrote:
    >>> thanks for this hint.
    >>>
    >>> On AMD cpus precise_ip maps to IBS, which does not support hardware
    >>> options as perfctrs do. Thus, following attr flags are not supported:
    >>>
    >>> exclude_user, exclude_kernel, exclude_host, exclude_guest
    >>>
    >>> Counting in guest mode is possible with IBS, but not the exclusion of
    >>> a certain mode. If precise_ip counting is enabled on AMD we may not
    >>> set the exclude_guest flag.
    >>
    >> IIRC we have SVM enter/exit hooks in kvm/perf already, we could use
    >> those to implement exclude_guest for IBS.
    >>
    >> Now I've been trying to find the patches that introduced that, but I'm
    >> failing horridly. Gleb, got us a pointer here?
    > The commit is 144d31e6, but it introduces hook that is used on VMX only.
    > SVM does not need it to implement guest/host only counters since it
    > has HW support for that in the PMU.

    Any updates?

    David



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