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

[Jiri Olsa]

On Mon, Dec 24, 2018 at 03:27:17PM +0300, Alexey Budankov wrote:
> 
> Build node cpu masks for mmap data buffers. Apply node cpu
> masks to tool thread every time it references data buffers
> cross node or cross cpu.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - separated AIO buffers binding to patch 2/4
> ---
>  tools/perf/builtin-record.c |  9 +++++++++
>  tools/perf/util/evlist.c    |  6 +++++-
>  tools/perf/util/mmap.c      | 12 ++++++++++++
>  tools/perf/util/mmap.h      |  1 +
>  4 files changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index b26febb54d01..eea96794ee45 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -536,6 +536,9 @@ static int record__mmap_evlist(struct record *rec,
>  	struct record_opts *opts = &rec->opts;
>  	char msg[512];
>  
> +	if (opts->affinity != PERF_AFFINITY_SYS)
> +		cpu__setup_cpunode_map();
> +
>  	if (perf_evlist__mmap_ex(evlist, opts->mmap_pages,
>  				 opts->auxtrace_mmap_pages,
>  				 opts->auxtrace_snapshot_mode,
> @@ -755,6 +758,12 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli
>  		struct perf_mmap *map = &maps[i];
>  
>  		if (map->base) {
> +			if (rec->opts.affinity != PERF_AFFINITY_SYS &&
> +			    !CPU_EQUAL(&rec->affinity_mask, &map->affinity_mask)) {
> +				CPU_ZERO(&rec->affinity_mask);
> +				CPU_OR(&rec->affinity_mask, &rec->affinity_mask, &map->affinity_mask);
> +				sched_setaffinity(0, sizeof(rec->affinity_mask), &rec->affinity_mask);

all this code depends on aio and LIBNUMA, let's keep it there then

also please add this and the affinity_mask setup code below to a function

thanks,
jirka

> +			}
>  			if (!record__aio_enabled(rec)) {
>  				if (perf_mmap__push(map, rec, record__pushfn) != 0) {
>  					rc = -1;
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 60e825be944a..5ca5bb5ea0db 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -1028,7 +1028,11 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
>  	 * Its value is decided by evsel's write_backward.
>  	 * So &mp should not be passed through const pointer.
>  	 */
> -	struct mmap_params mp = { .nr_cblocks = nr_cblocks, .affinity = affinity };
> +	struct mmap_params mp = {
> +		.nr_cblocks 	= nr_cblocks,
> +		.affinity 	= affinity,
> +		.cpu_map 	= cpus
> +	};
>  
>  	if (!evlist->mmap)
>  		evlist->mmap = perf_evlist__alloc_mmap(evlist, false);
> 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) {
> +				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);