perf tools: Handle TOPOLOGY headers with no CPU

[ Upstream commit 1497e804d1 ]

This patch fixes an issue in cpumap.c when used with the TOPOLOGY
header. In some configurations, some NUMA nodes may have no CPU (empty
cpulist). Yet a cpumap map must be created otherwise perf abort with an
error. This patch handles this case by creating a dummy map.

  Before:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  0x6e8 [0x6c]: failed to process type: 80

  After:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  noploop for 2 seconds

Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1547885559-1657-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Stephane Eranian 2019-01-19 00:12:39 -08:00 committed by Greg Kroah-Hartman
parent 482caab70b
commit 01b094e3c2

View file

@ -134,7 +134,12 @@ struct cpu_map *cpu_map__new(const char *cpu_list)
if (!cpu_list)
return cpu_map__read_all_cpu_map();
if (!isdigit(*cpu_list))
/*
* must handle the case of empty cpumap to cover
* TOPOLOGY header for NUMA nodes with no CPU
* ( e.g., because of CPU hotplug)
*/
if (!isdigit(*cpu_list) && *cpu_list != '\0')
goto out;
while (isdigit(*cpu_list)) {
@ -181,8 +186,10 @@ struct cpu_map *cpu_map__new(const char *cpu_list)
if (nr_cpus > 0)
cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
else
else if (*cpu_list != '\0')
cpus = cpu_map__default_new();
else
cpus = cpu_map__dummy_new();
invalid:
free(tmp_cpus);
out: