Messages in this thread | | | Date | Tue, 27 Oct 2015 11:23:37 +0800 | From | "Wangnan (F)" <> | Subject | Re: [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording |
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On 2015/10/26 21:02, Adrian Hunter wrote: > On 26/10/15 14:39, Wangnan (F) wrote: >> >> On 2015/10/26 20:24, Adrian Hunter wrote: >>> On 26/10/15 13:41, Wang Nan wrote: >>>> evsel->system_wide is introduced by commit bf8e8f4b832972c76d64ab2e2837 >>>> (perf evlist: Add 'system_wide' option), which is used for mixing evsels >>>> that aren't system-wide with ones that are [1]. However, for global >>>> system wide recording (perf record -a ...), evsel->system_wide is set >>>> to false, which is confusion. >>>> >>>> This patch set evsel->system_wide to true if the target.system_wide is >>>> set, which makes evsel->system_wide a reliable way to describe whether >>>> itself is system_wide or not. >>>> >>>> [1] http://lkml.kernel.org/r/562DF19B.2080608@intel.com >>>> >>>> Signed-off-by: Wang Nan <wangnan0@huawei.com> >>>> Cc: Adrian Hunter <adrian.hunter@intel.com> >>>> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> >>>> Cc: Alexei Starovoitov <ast@plumgrid.com> >>>> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> >>>> Cc: Li Zefan <lizefan@huawei.com> >>>> Cc: pi3orama@163.com >>>> Link: http://lkml.kernel.org/n/ebpf-qm3gtwidc1o5ktjd9tgjex25@git.kernel.org >>>> --- >>>> tools/perf/util/evsel.c | 1 + >>>> 1 file changed, 1 insertion(+) >>>> >>>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c >>>> index 3ac4ee9c..36ecf0e 100644 >>>> --- a/tools/perf/util/evsel.c >>>> +++ b/tools/perf/util/evsel.c >>>> @@ -734,6 +734,7 @@ void perf_evsel__config(struct perf_evsel *evsel, >>>> struct record_opts *opts) >>>> int track = evsel->tracking; >>>> bool per_cpu = opts->target.default_per_cpu && >>>> !opts->target.per_thread; >>>> + evsel->system_wide = opts->target.system_wide; >>> Well that breaks the way evsel->system_wide is used i.e. it is a parameter >>> to the evsel and here you just overwrote it. >> Currently the only user of evsel->system_wide is IPT: >> >> auxtrace_record__options -> intel_pt_recording_options >> >> and it only set it to true. >> >> So I think changing to this should make it safe: >> >> evsel->system_wide = (evsel->system_wide || opt->target.system_wide); >> >> Thought? > That would work although it looks like a kludge. > > Have you looked at properly validating opts->no_inherit ? > > Also, aren't you neglecting target->cpu_list ?
I need this because Alexei's bpf_perf_event_output() helper needs perf side support, and it only accept no-inherit perf event. I have already made a patch[1] to support setting inherit bit per-event, so even without this and next patch I can continue my work on bpf output. I'd like to rethink this patch after I finish perf support for bpf output.
Thank you.
[1] http://lkml.kernel.org/g/1445847884-143981-1-git-send-email-wangnan0@huawei.com
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