Re: [PATCH v11 0/4] perf tools: add support for libpfm4

Re: [PATCH v11 0/4] perf tools: add support for libpfm4

[Jiri Olsa]

On Thu, Apr 16, 2020 at 03:14:53PM -0700, Ian Rogers wrote:
> This patch links perf with the libpfm4 library if it is available
> and NO_LIBPFM4 isn't passed to the build. The libpfm4 library
> contains hardware event tables for all processors supported by
> perf_events. It is a helper library that helps convert from a
> symbolic event name to the event encoding required by the
> underlying kernel interface. This library is open-source and
> available from: http://perfmon2.sf.net.
>     
> With this patch, it is possible to specify full hardware events
> by name. Hardware filters are also supported. Events must be
> specified via the --pfm-events and not -e option. Both options
> are active at the same time and it is possible to mix and match:
>     
> $ perf stat --pfm-events inst_retired:any_p:c=1:i -e cycles ....
> 
> v11 reformats the perf list output to be:
> List of pre-defined events (to be used in -e):
> 
>   branch-instructions OR branches                    [Hardware event]
>   branch-misses                                      [Hardware event]
> ...
> 
> List of pre-defined events (to be used in --pfm-events):
> 
> ix86arch:
>   UNHALTED_CORE_CYCLES
>     [count core clock cycles whenever the clock signal on the specific core is running (not halted)]
>   INSTRUCTION_RETIRED
>     [count the number of instructions at retirement. For instructions that consists of multiple mic>
> ...
> skx:
>   UNHALTED_CORE_CYCLES
>     [Count core clock cycles whenever the clock signal on the specific core is running (not halted)]
> ...
>   BACLEARS
>     [Branch re-steered]
>       BACLEARS:ANY
>         [Number of front-end re-steers due to BPU misprediction]
> ...

Acked-by: Jiri Olsa <jolsa@redhat.com>

thanks,
jirka