On 4/25/2018 10:23 AM, Jiri Olsa wrote:
On Wed, Apr 25, 2018 at 06:50:18AM -0700, [email protected] wrote:
From: Kan Liang <[email protected]>
Perf stat doesn't count the uncore event aliases from the same uncore
block in a group, for example:
perf stat -e '{unc_m_cas_count.all,unc_m_clockticks}' -a -I 1000
# time counts unit events
1.000447342 <not counted> unc_m_cas_count.all
1.000447342 <not counted> unc_m_clockticks
2.000740654 <not counted> unc_m_cas_count.all
2.000740654 <not counted> unc_m_clockticks
The output is very misleading. It gives a wrong impression that the
uncore event doesn't work.
An uncore block could be composed by several PMUs. An uncore event alias
is a joint name which means the same event runs on all PMUs of a block.
Perf doesn't support mixed events from different PMUs in the same group.
It is wrong to put uncore event aliases in a big group.
The right way is to split the big group into multiple small groups which
only include the events from the same PMU.
Only uncore event aliases from the same uncore block should be specially
handled here. It doesn't make sense to mix the uncore events with other
uncore events from different blocks or even core events in a group.
With the patch:
# time counts unit events
1.001557653 140,833 unc_m_cas_count.all
1.001557653 1,330,231,332 unc_m_clockticks
2.002709483 85,007 unc_m_cas_count.all
2.002709483 1,429,494,563 unc_m_clockticks
hum, I still can see the original behaviour even with the patch:
That's because the data_reads and clockticks are from different uncore
blocks. The data_reads is a IMC event. The clockticks is a CBOX event.
The patch only supports the events from the same uncore blocks in group.
Thanks,
Kan
[jolsa@krava perf]$ sudo ./perf stat -e '{data_reads,clockticks}' -a -I 1000
# time counts unit events
1.000184929 <not counted> MiB data_reads
1.000184929 <not supported> clockticks
2.000552765 <not counted> MiB data_reads
2.000552765 <not supported> clockticks
3.000846298 <not counted> MiB data_reads
3.000846298 <not supported> clockticks
4.001044852 <not counted> MiB data_reads
4.001044852 <not supported> clockticks
5.001247131 <not counted> MiB data_reads
5.001247131 <not supported> clockticks
^C 5.546917060 <not counted> MiB data_reads
5.546917060 <not supported> clockticks
jirka
