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Date:   Fri, 10 Jan 2020 09:31:07 -0800
From:   Andi Kleen <ak@linux.intel.com>
To:     Jiri Olsa <jolsa@kernel.org>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Jann Horn <jannh@google.com>,
        lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Michael Petlan <mpetlan@redhat.com>
Subject: Re: [PATCH] perf tools: Setup initial evlist::all_cpus value
Message-ID: <20200110173107.GU15478@tassilo.jf.intel.com>
References: <20200110151537.153012-1-jolsa@kernel.org>
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On Fri, Jan 10, 2020 at 04:15:37PM +0100, Jiri Olsa wrote:
> Jann Horn reported crash in perf ftrace because evlist::all_cpus
> isn't initialized if there's evlist without events, which is the
> case for perf ftrace.
> 
> Adding initial initialization of evlist::all_cpus from given cpus,
> regardless of events in the evlist.

Acked-by: Andi Kleen <ak@linux.intel.com>

> 
> Reported-by: Jann Horn <jannh@google.com>
> Link: https://lkml.kernel.org/n/tip-kzioebqr5c3u4t7tafju8pbx@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  tools/lib/perf/evlist.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
> index ae9e65aa2491..5b9f2ca50591 100644
> --- a/tools/lib/perf/evlist.c
> +++ b/tools/lib/perf/evlist.c
> @@ -164,6 +164,9 @@ void perf_evlist__set_maps(struct perf_evlist *evlist,
>  		evlist->threads = perf_thread_map__get(threads);
>  	}
>  
> +	if (!evlist->all_cpus && cpus)
> +		evlist->all_cpus = perf_cpu_map__get(cpus);
> +
>  	perf_evlist__propagate_maps(evlist);
>  }
>  
> -- 
> 2.24.1
>