Messages in this thread | | | Date | Tue, 16 Oct 2012 12:08:09 +0200 | From | Robert Richter <> | Subject | Re: [RFC][PATCH] perf: Add a few generic stalled-cycles events |
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Sukadev,
On 15.10.12 17:55:34, Robert Richter wrote: > On 11.10.12 18:28:39, Sukadev Bhattiprolu wrote: > > + { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_FIXED_POINT }, > > + { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_LOAD_STORE }, > > + { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_INSTRUCTION_FETCH }, > > + { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_BRANCH }, > > Instead of adding new hardware event types I would prefer to use raw > events in conjunction with sysfs, see e.g. the intel-uncore > implementation. Something like: > > $ find /sys/bus/event_source/devices/cpu/events/ > ... > /sys/bus/event_source/devices/cpu/events/stalled-cycles-fixed-point > /sys/bus/event_source/devices/cpu/events/stalled-cycles-load-store > /sys/bus/event_source/devices/cpu/events/stalled-cycles-instruction-fetch > /sys/bus/event_source/devices/cpu/events/stalled-cycles-branch > ... > $ cat /sys/bus/event_source/devices/cpu/events/stalled-cycles-fixed-point > event=0xff,umask=0x00 > > Perf tool works then out-of-the-box with: > > $ perf record -e cpu/stalled-cycles-fixed-point/ ...
I refer here to arch/x86/kernel/cpu/perf_event_intel_uncore.c (should be in v3.7-rc1 or tip:perf/core). See the INTEL_UNCORE_EVENT_DESC() macro and 'if (type->event_descs) ...' in uncore_type_init(). The code should be reworked to be non-architectural.
PMU registration is implemented for a longer time already for all architectures and pmu types:
/sys/bus/event_source/devices/*
But
/sys/bus/event_source/devices/*/events/
exists only for a small number of pmus. Perf tool support of this was implemented with:
a6146d5 perf/tool: Add PMU event alias support
-Robert
-- Advanced Micro Devices, Inc. Operating System Research Center
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