Re: [PATCH V2 07/14] perf tools: Add evsel->own_cpus

From: Jiri Olsa
Date: Tue Sep 08 2015 - 03:39:03 EST


On Tue, Sep 08, 2015 at 10:09:10AM +0300, Adrian Hunter wrote:
> On 08/09/15 09:45, Jiri Olsa wrote:
> > On Mon, Sep 07, 2015 at 05:27:49PM +0300, Adrian Hunter wrote:
> >> perf_evlist__propagate_maps() cannot easily tell if an evsel
> >> has its own cpu map. To make that simpler, keep a copy of
> >> the PMU cpu map and adjust the propagation logic accordingly.
> >>
> >> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> >> ---
> >> tools/perf/util/evlist.c | 5 ++++-
> >> tools/perf/util/evsel.c | 1 +
> >> tools/perf/util/evsel.h | 1 +
> >> tools/perf/util/parse-events.c | 4 ++--
> >> 4 files changed, 8 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> >> index c959c42080e3..6764e0eff849 100644
> >> --- a/tools/perf/util/evlist.c
> >> +++ b/tools/perf/util/evlist.c
> >> @@ -1111,9 +1111,12 @@ static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
> >> * We already have cpus for evsel (via PMU sysfs) so
> >> * keep it, if there's no target cpu list defined.
> >> */
> >> - if (!evsel->cpus || evlist->has_user_cpus) {
> >> + if (!evsel->own_cpus || evlist->has_user_cpus) {
> >> cpu_map__put(evsel->cpus);
> >> evsel->cpus = cpu_map__get(evlist->cpus);
> >> + } else if (evsel->cpus != evsel->own_cpus) {
> >> + cpu_map__put(evsel->cpus);
> >> + evsel->cpus = cpu_map__get(evsel->own_cpus);
> >
> > hum, so (evsel->cpus != evsel->own_cpus) could happen only when:
> > - evsel->own_cpus != NULL
> > - we overloaded evsel->cpus with evlist->cpus via perf_evlist__propagate_maps
> > - we changed evlist->has_user_cpus = false
> > - we recall perf_evlist__propagate_maps
> >
> > I'm missing usecase for that, or something else ;-)
>
> That's true but the idea is to establish rules (invariants) that are always
> true. Like an evsel either has its own cpu map or the same as the evlist.

ook, jirka
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