The following commit has been merged into the perf/core branch of tip:
Commit-ID: df552793493ff83b2b7289389d29d417b3ef6d6d
Gitweb: https://git.kernel.org/tip/df552793493ff83b2b7289389d29d417b3ef6d6d
Author: Kyle Meyer <meyerk@xxxxxxx>
AuthorDate: Tue, 27 Aug 2019 16:43:52 -05:00
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Thu, 29 Aug 2019 17:38:32 -03:00
libperf: Warn when exceeding MAX_NR_CPUS in cpumap
Display a warning when attempting to profile more than MAX_NR_CPU CPUs.
This patch should not change any behavior.
Signed-off-by: Kyle Meyer <kyle.meyer@xxxxxxx>
Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Russ Anderson <russ.anderson@xxxxxxx>
Link: http://lore.kernel.org/lkml/20190827214352.94272-8-meyerk@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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 2834753..1f0e6f3 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++)
|