perf tools: handle TOPOLOGY headers with no CPU
diff mbox series

Message ID 1547885559-1657-1-git-send-email-eranian@google.com
State Accepted
Commit 1497e804d1a6e2bd9107ddf64b0310449f4673eb
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Series
  • perf tools: handle TOPOLOGY headers with no CPU
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Commit Message

Stephane Eranian Jan. 19, 2019, 8:12 a.m. UTC
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>
---
 tools/perf/util/cpumap.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Comments

Jiri Olsa Jan. 20, 2019, 6:19 p.m. UTC | #1
On Sat, Jan 19, 2019 at 12:12:39AM -0800, Stephane Eranian wrote:
> 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>

thanks,
jirka

> ---
>  tools/perf/util/cpumap.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> index 1ccbd3342069..383674f448fc 100644
> --- a/tools/perf/util/cpumap.c
> +++ b/tools/perf/util/cpumap.c
> @@ -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:
> -- 
> 2.7.4
>

Patch
diff mbox series

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 1ccbd3342069..383674f448fc 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -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: