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    SubjectRe: [PATCH 0/9] oprofile, perf, x86: introduce new functions to reserve perfctrs
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    On Thu, 2010-03-04 at 18:59 +0100, Peter Zijlstra wrote:
    > On Thu, 2010-03-04 at 16:22 +0100, Robert Richter wrote:
    > > This patch set improves the perfctr reservation code. New functions
    > > are available to reserve a counter by its index only. It is no longer
    > > necessary to allocate both msrs of a counter which also improves the
    > > code and makes it easier.
    > >
    > > For oprofile a handler is implemented that returns an error now if a
    > > counter is already reserved by a different subsystem such as perf or
    > > watchdog. Before, oprofile silently ignored that counter. Finally the
    > > new reservation functions can be used to allocate special parts of the
    > > pmu such as IBS, which is necessary to use IBS with perf too.
    > >
    > > The patches are available in the oprofile tree:
    > >
    > > git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile.git core
    > >
    > > If there are no objections, I suggest to merge it into the
    > > tip/perf/core too, maybe after pending patches went in. If there are
    > > already conflicts, I will do the merge for this.
    >
    > Right, so cleaning up that reservation code is nice, but wouldn't it be
    > much nicer to simply do away with all that and make everything use the
    > (low level) perf code?

    Alternatively, could we maybe further simplify this reservation into:

    int reserve_pmu(void);
    void release_pmu(void);

    And not bother with anything finer grained.



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