Messages in this thread | | | Date | Thu, 21 Jun 2012 11:13:30 +0200 | Subject | Re: [PATCH V6 0/13] perf: Intel uncore pmu counting support | From | Stephane Eranian <> |
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On Thu, Jun 21, 2012 at 10:43 AM, Yan, Zheng <zheng.z.yan@intel.com> wrote: > On 06/21/2012 04:10 PM, Stephane Eranian wrote: >> On Thu, Jun 21, 2012 at 4:34 AM, Yan, Zheng <zheng.z.yan@intel.com> wrote: >>> On 06/21/2012 12:01 AM, Peter Zijlstra wrote: >>>> >>>> ok, so with this stuff something like: >>>> >>>> perf stat -ae uncore/event=clockticks/ foo >>>> >>>> will register a counter per cpu, which is somewhat silly since we only >>>> need one per node. What would be the best way to 'fix' this? >>>> >>>> We could of course create another variant of -a which iterates nodes >>>> instead of cpus, -N or so. >>>> >>>> Alternatively we could try and describe this in sysfs in some way, one >>>> possibility would be to include a link to /sys/devices/system/{cpu,node} >>>> or somesuch and use that link to iterate the correct space. >>>> >>>> Any other suggestions? >>>> >>> How about treat the 'cpu' parameter for uncore event as socket id instead >>> of cpu id? >>> >> But that does not address the use case of Peter, i.e., no cpu parameter passed. >> Looks like sysfs might be the only way to do this in a portable manner. >> > It does. For example, on a dual socket system, perf can only register uncore > counter with 'cpu' parameter is equal to 0 or 1. This method is hacky, but it > requires minimal change for the kernel and perf tool. > I was saying, I don't want to have to pass -C x with -a and yet have perf stat only instantiate the event once per socket. I think that's what PeterZ was asking about.
> Regards > Yan, Zheng > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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