Messages in this thread | | | Subject | Re: [RFC] perf_events: support for uncore a.k.a. nest units | From | Peter Zijlstra <> | Date | Mon, 01 Feb 2010 20:54:21 +0100 |
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On Mon, 2010-02-01 at 11:39 -0800, Corey Ashford wrote: > > On 1/30/2010 12:42 AM, Peter Zijlstra wrote: > > On Fri, 2010-01-29 at 15:05 -0800, Corey Ashford wrote: > >> So you'd read the id from the sysfs topology tree, and then pass that id to the > >> interface? That's an interesting approach that eliminates the need to pass a > >> string pmu path to the kernel. > > > > No, the attr.pmu_id would reflect the location in the tree (pci > > location, or spu number), the pmu id reported would identify the kind of > > pmu driver used for that particular device. > > > > I realized this confusion after sending but didn't clarify, we should > > come up with a good alternative name for either (or both) uses. > > > > Ok, just so I'm clear here, is attr.pmu_id a (char *) or some sort of encoded > bit field?
Right, currently on x86 we have x86_pmu.name which basically tells us what kind of pmu it is, but we really don't export that since its trivial to see that from /proc/cpuinfo, but the ARM people expressed interest in this because decoding the cpuid equivalent on arm is like nasty business.
But once we go add other funny pmu's, it becomes interesting to know what kind of pmu it is and tie possible event sets to them.
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