Re: [PATCH 5/9] perf tools: Introduce 'P' modifier

Jiri Olsa
2015-10-05T18:38:12Z

On Mon, Oct 05, 2015 at 12:13:48PM -0600, David Ahern wrote:
> On 10/5/15 12:06 PM, Jiri Olsa wrote:
> >The 'P' will cause the event to get maximum possible
> >detected precise level.
> >
> >Following record:
> > $ perf record -e cycles:P ...
> >
> >will detect maximum precise level for 'cycles' event
> >and use it.
> >
>
> Does the end result (which precise level is used) get saved to the header
> and displayed to the user properly?

yep..

[jolsa@krava perf]$ ./perf record -e cycles:P ls

...

[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data (8 samples) ]
[jolsa@krava perf]$ ./perf evlist
cycles:P
[jolsa@krava perf]$ ./perf evlist -v
cycles:P: size: 112, ... precise_ip: 2 ...

[jolsa@krava perf]$ ./perf report --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 8 of event 'cycles:P'
# Event count (approx.): 4270406
#
# Overhead Command Shared Object Symbol
...

jirka