On Wed, 2017-08-23 at 20:01 +0200, Peter Zijlstra wrote: > On Wed, Aug 23, 2017 at 05:51:38PM +0000, Rogozhkin, Dmitry V wrote: > > > https://patchwork.freedesktop.org/patch/171953/. This patch makes 'perf > > stat -e i915/rcs0-busy/' to error out and supports 'perf stat -e > > i915/rcs0-busy/ -a -C0'. I still think I miss something since 'perf stat > > -e i915/rcs0-busy/ -a' will give metrics multiplied by number of active > > CPUs, but that's look closer to what is needed. > > IIRC an uncore PMU should expose a cpumask through sysfs, and then perf > tools will read that mask and auto-magically limit the number of CPUs it > instantiates the counter on. > > See for instance arch/x86/events/intel/cstate.c, that is a fairly > trivial uncore PMU, look for "DEVICE_ATTR(cpumask". Thank you for the reference! I will go forward and try to implement this for i915 PMU. > > For example, on my 2 socket 10 core ivb-ep: > > root@ivb-ep:~# cat /sys/bus/event_source/devices/cstate_pkg/cpumask > 0,10 > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
