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author | Kan Liang <kan.liang@linux.intel.com> | 2020-03-19 23:25:01 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-04-18 15:05:00 +0300 |
commit | 9fbc61f832ebf432326a90e28184dade05ee34a8 (patch) | |
tree | df8ec153f6a72fd741c850b6015b41ca894c30bf /tools/perf/Documentation | |
parent | f8ff18be1f5c6ba1c2befb043bea6e7eaf9f8987 (diff) | |
download | linux-9fbc61f832ebf432326a90e28184dade05ee34a8.tar.xz |
perf pmu: Add support for PMU capabilities
The PMU capabilities information, which is located at
/sys/bus/event_source/devices/<dev>/caps, is required by perf tool. For
example, the max LBR information is required to stitch LBR call stack.
Add perf_pmu__caps_parse() to parse the PMU capabilities information.
The information is stored in a list.
The following patch will store the capabilities information in perf
header.
Committer notes:
Here's an example of such directories and its files in an i5 7th gen
machine:
[root@seventh ~]# ls -lad /sys/bus/event_source/devices/*/caps
drwxr-xr-x. 2 root root 0 Apr 14 13:33 /sys/bus/event_source/devices/cpu/caps
drwxr-xr-x. 2 root root 0 Apr 14 13:33 /sys/bus/event_source/devices/intel_pt/caps
[root@seventh ~]# ls -la /sys/bus/event_source/devices/intel_pt/caps
total 0
drwxr-xr-x. 2 root root 0 Apr 14 13:33 .
drwxr-xr-x. 5 root root 0 Apr 14 13:12 ..
-r--r--r--. 1 root root 4096 Apr 16 13:10 cr3_filtering
-r--r--r--. 1 root root 4096 Apr 16 11:42 cycle_thresholds
-r--r--r--. 1 root root 4096 Apr 16 13:10 ip_filtering
-r--r--r--. 1 root root 4096 Apr 16 13:10 max_subleaf
-r--r--r--. 1 root root 4096 Apr 14 13:33 mtc
-r--r--r--. 1 root root 4096 Apr 14 13:33 mtc_periods
-r--r--r--. 1 root root 4096 Apr 16 13:10 num_address_ranges
-r--r--r--. 1 root root 4096 Apr 16 13:10 output_subsys
-r--r--r--. 1 root root 4096 Apr 16 13:10 payloads_lip
-r--r--r--. 1 root root 4096 Apr 16 13:10 power_event_trace
-r--r--r--. 1 root root 4096 Apr 14 13:33 psb_cyc
-r--r--r--. 1 root root 4096 Apr 14 13:33 psb_periods
-r--r--r--. 1 root root 4096 Apr 16 13:10 ptwrite
-r--r--r--. 1 root root 4096 Apr 16 13:10 single_range_output
-r--r--r--. 1 root root 4096 Apr 16 12:03 topa_multiple_entries
-r--r--r--. 1 root root 4096 Apr 16 13:10 topa_output
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/topa_output
1
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/topa_multiple_entries
1
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/mtc
1
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/power_event_trace
0
[root@seventh ~]#
[root@seventh ~]# ls -la /sys/bus/event_source/devices/cpu/caps/
total 0
drwxr-xr-x. 2 root root 0 Apr 14 13:33 .
drwxr-xr-x. 6 root root 0 Apr 14 13:12 ..
-r--r--r--. 1 root root 4096 Apr 16 13:10 branches
-r--r--r--. 1 root root 4096 Apr 14 13:33 max_precise
-r--r--r--. 1 root root 4096 Apr 16 13:10 pmu_name
[root@seventh ~]# cat /sys/bus/event_source/devices/cpu/caps/max_precise
3
[root@seventh ~]# cat /sys/bus/event_source/devices/cpu/caps/branches
32
[root@seventh ~]# cat /sys/bus/event_source/devices/cpu/caps/pmu_name
skylake
[root@seventh ~]#
Wow, first time I've heard about
/sys/bus/event_source/devices/cpu/caps/max_precise, I think I'll use it!
:-)
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-2-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
0 files changed, 0 insertions, 0 deletions