Re: [PATCH v1 2/3] perf record: apply affinity masks when reading mmap buffers

From: Jiri Olsa
Date: Wed Dec 12 2018 - 07:15:43 EST


On Wed, Dec 12, 2018 at 10:40:22AM +0300, Alexey Budankov wrote:

SNIP

> 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
> @@ -344,6 +369,17 @@ 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) {
> + CPU_SET(c, &map->affinity_mask);
> + }
> + }
> + } else if (mp->affinity == PERF_AFFINITY_CPU) {
> + CPU_SET(map->cpu, &map->affinity_mask);
> + }

won't both of this end up in same mask?

jirka