Commit 1497e804 authored Jan 19, 2019 by Stephane Eranian Committed by Arnaldo Carvalho de Melo Jan 21, 2019

perf tools: Handle TOPOLOGY headers with no CPU



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>

parent 94ec1eb7

tools/perf/util/cpumap.c

+9 −2

Original line number	Original line	Diff line number	Diff line
	@@ -134,7 +134,12 @@ struct cpu_map cpu_map__new(const char cpu_list)
	if (!cpu_list)		if (!cpu_list)
	return cpu_map__read_all_cpu_map();		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;		goto out;

	while (isdigit(*cpu_list)) {		while (isdigit(*cpu_list)) {
	@@ -181,8 +186,10 @@ struct cpu_map cpu_map__new(const char cpu_list)

	if (nr_cpus > 0)		if (nr_cpus > 0)
	cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);		cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
	else		else if (*cpu_list != '\0')
	cpus = cpu_map__default_new();		cpus = cpu_map__default_new();
			else
			cpus = cpu_map__dummy_new();
	invalid:		invalid:
	free(tmp_cpus);		free(tmp_cpus);
	out:		out: