Messages in this thread | | | Date | Mon, 26 Jan 2009 23:10:38 +0100 | From | Ingo Molnar <> | Subject | Re: [perfmon2] [announce] Performance Counters for Linux, v6 |
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* Luck, Tony <tony.luck@intel.com> wrote:
> > - or the PMU capability is expressed as a special counter type (if it's > > useful enough) - and then either the write() method or ioctl is extended > > to express attributes we want to set/change while a counter is running. > > The product of: > {exotic PMU modes} * {creative performance measurement ideas} > > will produce a large number of candidates for these special counters (at > least on ia64 ... which has a large number of exotic PMU options). > > I don't think that I'm qualified to judge which of them are "useful > enough" to warrant a special counter type.
it should certainly be done on a case by case basis. They need to be consciously exposed not just summarily exported to user-space, because PMU hw features have security implications so it has to be done all explicitly.
Ingo
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