Messages in this thread Patch in this message |  | | | From | Namhyung Kim <> | | Subject | Re: [PATCH 2/3] Revert 'perf evlist: Fix creation of cpu map' | | Date | Thu, 17 May 2012 17:57:16 +0900 |
| |
Hi,
On Wed, 16 May 2012 12:26:19 -0300, Arnaldo Carvalho de Melo wrote: > Em Wed, May 16, 2012 at 06:45:48PM +0900, Namhyung Kim escreveu: >> The commit 55261f46702c ("perf evlist: Fix creation of cpu >> map") changed to create a per-task event when no cpu target >> is specified. However it caused a problem since perf-task do >> not allow event inheritance due to scalability issues so >> that the result will contain samples only from parent, not >> from its children. >> >> So we should use perf-task-per-cpu events anyway to get the >> right result. Revert it. >> >> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> >> Analysed-by: Ingo Molnar <mingo@kernel.org> >> Acked-and-tested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > > I'm applying it, but while trying to figure out if the logic was right I > tried: > > perf top -C 0 -u acme > > To check what is that this user is doing on that CPU, and its not > possible :-\ > > UID switch overriding CPU! >
Maybe I need to rethink about it since I wasn't aware of the per-task-per-cpu events at that time.
AFAIK the uid switch is basically a same thing as pid/tid switch, so your complain should be extended to them too. And I think we can remove the check from perf_target__validate(). But before that something like below is needed also IMHO:
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index ebcd15883ab8..8e3cf429dd18 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -900,6 +900,9 @@ static void perf_top__start_counters(struct perf_top *top) attr->read_format |= PERF_FORMAT_ID; } + if (perf_target__has_cpu(&top->target)) + attr->sample_type |= PERF_SAMPLE_CPU; + if (symbol_conf.use_callchain) attr->sample_type |= PERF_SAMPLE_CALLCHAIN; diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index d7a2b4b9801d..d26b8fe0abd1 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -107,7 +107,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct perf_record_opts *opts, if (opts->call_graph) attr->sample_type |= PERF_SAMPLE_CALLCHAIN; - if (opts->target.system_wide) + if (perf_target__has_cpu(&opts->target)) attr->sample_type |= PERF_SAMPLE_CPU; if (opts->period)
|  |