Re: [PATCH v2 3/4] perf record: apply affinity masks when reading mmap buffers

Jiri Olsa
2019-01-01T21:39:37Z

On Mon, Dec 24, 2018 at 03:27:17PM +0300, Alexey Budankov wrote:

SNIP

> diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
> index 742fa9a8e498..a2095e4eda4b 100644
> --- a/tools/perf/util/mmap.c
> +++ b/tools/perf/util/mmap.c
> @@ -361,6 +361,7 @@ void perf_mmap__munmap(struct perf_mmap *map)
>
> int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int cpu)
> {
> + int c, nr_cpus, node;
> /*
> * The last one will be done at perf_mmap__consume(), so that we
> * make sure we don't prevent tools from consuming every last event in
> @@ -389,6 +390,17 @@ int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int c
> map->cpu = cpu;
>
> CPU_ZERO(&map->affinity_mask);
> + if (mp->affinity == PERF_AFFINITY_NODE && cpu__max_node() > 1) {
> + nr_cpus = cpu_map__nr(mp->cpu_map);
> + node = cpu__get_node(map->cpu);
> + for (c = 0; c < nr_cpus; c++) {
> + if (cpu__get_node(c) == node) {

the 'c' is just an index here, I think you need to
use the real cpu value from the mp->cpu_map->map[c]

jirka

> + CPU_SET(c, &map->affinity_mask);
> + }
> + }
> + } else if (mp->affinity == PERF_AFFINITY_CPU) {
> + CPU_SET(map->cpu, &map->affinity_mask);
> + }
>
> if (auxtrace_mmap__mmap(&map->auxtrace_mmap,
> &mp->auxtrace_mp, map->base, fd))
> diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
> index e566c19b242b..b3f724fad22e 100644
> --- a/tools/perf/util/mmap.h
> +++ b/tools/perf/util/mmap.h
> @@ -72,6 +72,7 @@ enum bkw_mmap_state {
> struct mmap_params {
> int prot, mask, nr_cblocks, affinity;
> struct auxtrace_mmap_params auxtrace_mp;
> + const struct cpu_map *cpu_map;
> };
>
> int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int cpu);