On Mon, Feb 13, 2017 at 04:34:35PM +0100, Jan Stancek wrote:
SNIP
> This patch makes build_cpu_topology() skip offline/absent CPUs,
> by checking their presence against cpu_map built from online CPUs.
>
> Signed-off-by: Jan Stancek <jstan...@redhat.com>
> ---
> tools/perf/util/header.c | 21 +++++++++++++++++----
> 1 file changed, 17 insertions(+), 4 deletions(-)
>
> Changes in v2:
> - drop out label, use return NULL where possible
>
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index d89c9c7ef4e5..4b0ea4e92e9d 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -503,24 +503,31 @@ static void free_cpu_topo(struct cpu_topo *tp)
>
> static struct cpu_topo *build_cpu_topology(void)
> {
> - struct cpu_topo *tp;
> + struct cpu_topo *tp = NULL;
> void *addr;
> u32 nr, i;
> size_t sz;
> long ncpus;
> - int ret = -1;
> + int ret = 0;
hum, shoudn't we fail if we dont find any online cpu?
jirka
> + struct cpu_map *map;
>
> ncpus = sysconf(_SC_NPROCESSORS_CONF);
> if (ncpus < 0)
> return NULL;
>
> + /* build online CPU map */
> + map = cpu_map__new(NULL);
> + if (map == NULL) {
> + pr_debug("failed to get system cpumap\n");
> + return NULL;
> + }
> +
> nr = (u32)(ncpus & UINT_MAX);
>
> sz = nr * sizeof(char *);
> -
> addr = calloc(1, sizeof(*tp) + 2 * sz);
> if (!addr)
> - return NULL;
> + goto out_free;
>
> tp = addr;
> tp->cpu_nr = nr;
> @@ -530,10 +537,16 @@ static struct cpu_topo *build_cpu_topology(void)
> tp->thread_siblings = addr;
>
> for (i = 0; i < nr; i++) {
> + if (!cpu_map__has(map, i))
> + continue;
> +
> ret = build_cpu_topo(tp, i);
> if (ret < 0)
> break;
> }
> +
> +out_free:
> + cpu_map__put(map);
> if (ret) {
> free_cpu_topo(tp);
> tp = NULL;
> --
> 1.8.3.1
>
