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Power7 supports over 530 different perf events but only a small subset
of these can be specified by name, for the remaining events, we must
specify them by their raw code:
perf stat -e r2003c <application>
This patch makes all the POWER7 events available in sysfs. So we can
instead specify these as:
perf stat -e 'cpu/PM_CMPLU_STALL_DFU/' <application>
where PM_CMPLU_STALL_DFU is the r2003c in previous example.
Before this patch is applied, the size of power7-pmu.o is:
$ size arch/powerpc/perf/power7-pmu.o
text data bss dec hex filename
3073 2720 0 5793 16a1 arch/powerpc/perf/power7-pmu.o
and after the patch is applied, it is:
$ size arch/powerpc/perf/power7-pmu.o
text data bss dec hex filename
15950 31112 0 47062 b7d6 arch/powerpc/perf/power7-pmu.o
For the run time overhead, I use two scripts, one is "event_name.sh",
which contains 50 event names, it looks like:
# ./perf record -e 'cpu/PM_CMPLU_STALL_DFU/' -e ..... /bin/sleep 1
the other one is named "event_code.sh" which use corresponding events
raw
code instead of events names, it looks like:
# ./perf record -e r2003c -e ...... /bin/sleep 1
below is the result.
Using events name:
[root@localhost perf]# time ./event_name.sh
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.002 MB perf.data (~102 samples) ]
real 0m1.192s
user 0m0.028s
sys 0m0.106s
Using events raw code:
[root@localhost perf]# time ./event_code.sh
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.003 MB perf.data (~112 samples) ]
real 0m1.198s
user 0m0.028s
sys 0m0.105s
Signed-off-by: Runzhen Wang <[email protected]>
Acked-by: Michael Ellerman <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Michael Ellerman <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Runzhen Wang <[email protected]>
Cc: Sukadev Bhattiprolu <[email protected]>
Cc: Xiao Guangrong <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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