Messages in this thread Patch in this message | | | From | Kyle Meyer <> | Subject | [PATCH v4 7/7] perf/lib/cpumap: Warn when exceeding MAX_NR_CPUS | Date | Tue, 27 Aug 2019 16:43:52 -0500 |
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Display a warning when attempting to profile more than MAX_NR_CPU CPUs. This patch should not change any behavior.
Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: Russ Anderson <russ.anderson@hpe.com> Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com> --- tools/perf/lib/cpumap.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/tools/perf/lib/cpumap.c b/tools/perf/lib/cpumap.c index 2834753576b2..1f0e6f334237 100644 --- a/tools/perf/lib/cpumap.c +++ b/tools/perf/lib/cpumap.c @@ -100,6 +100,9 @@ struct perf_cpu_map *perf_cpu_map__read(FILE *file) if (prev >= 0) { int new_max = nr_cpus + cpu - prev - 1; + WARN_ONCE(new_max >= MAX_NR_CPUS, "Perf can support %d CPUs. " + "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS); + if (new_max >= max_entries) { max_entries = new_max + MAX_NR_CPUS / 2; tmp = realloc(tmp_cpus, max_entries * sizeof(int)); @@ -192,6 +195,9 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) end_cpu = start_cpu; } + WARN_ONCE(end_cpu >= MAX_NR_CPUS, "Perf can support %d CPUs. " + "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS); + for (; start_cpu <= end_cpu; start_cpu++) { /* check for duplicates */ for (i = 0; i < nr_cpus; i++) -- 2.12.3
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