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Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support

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Em Thu, Aug 06, 2015 at 03:44:53PM -0400, kan.liang@intel.com escreveu:
> From: Kan Liang <kan.liang@intel.com>
> Here are some examples and test results.
> 
> 1. Comparing the elapsed time and perf.data size from "kernbench -M -H".
> 
>  The test command for FULL callgraph and time support.
>    "perf record -e
>    '{cpu/cpu-cycles,period=100000/,cpu/instructions,period=20000/p}'
>    --call-graph fp --time"

Jiri, while testing this I noticed that the message for EINVAL when
using the cpu// syntax (per-event settings) is cryptic:

  [root@zoo ~]# perf record -e 'cpu/cpu-cycles,call-graph=fp,time,period=100000/p' ls
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cpu/cpu-cycles,call-graph=fp,time,period=100000/p).
  /bin/dmesg may provide additional information.
  No CONFIG_PERF_EVENTS=y kernel support configured?

Whereas if we use -F, it is much, much clearer, telling the user exactly
what is failing and what needs to be done to make it work:

  [root@zoo ~]# perf record -F 100000 -e cpu/cpu-cycles/ usleep 1
  Maximum frequency rate (25000) reached.
  Please use -F freq option with lower value or consider
  tweaking /proc/sys/kernel/perf_event_max_sample_rate.
  [root@zoo ~]# 

Hope this is something easy to wire up, given your event parsing kung foo
skillz...

;-)

- Arnaldo
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Thread

[PATCH RFC V9 1/3] perf,tools: move callchain option parse code to util.c kan.liang@intel.com - 2015-08-07 05:10 +0200
  [PATCH RFC V9 2/3] perf,tools: per-event callgraph support kan.liang@intel.com - 2015-08-07 05:10 +0200
    Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support Jiri Olsa <jolsa@redhat.com> - 2015-08-07 13:00 +0200
    Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-07 17:50 +0200
      Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support Jiri Olsa <jolsa@redhat.com> - 2015-08-08 18:50 +0200
        Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-08 19:40 +0200
      RE: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support "Liang, Kan" <kan.liang@intel.com> - 2015-08-10 15:00 +0200
        Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-10 17:40 +0200
          RE: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support "Liang, Kan" <kan.liang@intel.com> - 2015-08-10 21:00 +0200
            Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-10 21:40 +0200
    Re: [PATCH RFC V9 2/3] perf,tools: per-event callgraph support Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-07 18:00 +0200
      [PATCH] perf tools: Unset perf_event_attr::freq when period term is  set Jiri Olsa <jolsa@redhat.com> - 2015-08-08 19:20 +0200
        [tip:perf/core] perf tools: Unset perf_event_attr::  freq when period term is set tip-bot for Jiri Olsa <tipbot@zytor.com> - 2015-08-12 14:40 +0200
  [PATCH] perf tools: Move perf_counts struct and functions into  separate object Jiri Olsa <jolsa@redhat.com> - 2015-08-07 13:00 +0200
    Re: [PATCH] perf tools: Move perf_counts struct and functions into  separate object Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-07 15:20 +0200
    [tip:perf/core] perf stat:   Move perf_counts struct and functions into separate object tip-bot for Jiri Olsa <tipbot@zytor.com> - 2015-08-12 14:30 +0200
  [tip:perf/core] perf callchain:   Move option parsing code to util.c tip-bot for Kan Liang <tipbot@zytor.com> - 2015-08-12 14:30 +0200

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