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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 1 Jan 2019 22:39:32 +0100
From:   Jiri Olsa <jolsa@...hat.com>
To:     Alexey Budankov <alexey.budankov@...ux.intel.com>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Andi Kleen <ak@...ux.intel.com>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 3/4] perf record: apply affinity masks when reading
 mmap buffers

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);