Re: [PATCH 1/3] perf bench futex: benchmark only online CPUs

Arnaldo Carvalho de Melo
2017-11-23T15:09:52Z

Em Wed, Nov 22, 2017 at 06:25:28PM -0600, Kim Phillips escreveu:
> From: James Yang <james.yang@arm.com>
>
> The "perf bench futex" benchmarks have a problem when not all CPUs in
> the system are online: perf assumes the CPUs that are online are
> contiguously numbered and assigns processor affinity to the threads by
> modulo striping. When the online CPUs are not contiguously numbered,
> perf errors out with:
>
> $ echo 0 | sudo tee /sys/devices/system/cpu/cpu3/online
> 0
> $ ./oldperf bench futex all
> perf: pthread_create: Operation not permitted
> Run summary [PID 14934]: 7 threads, each operating on 1024 [private] futexes for 10 secs.
>
> $
>
> This patch makes perf not assume all CPUs configured are online, and
> adds a mapping table to stripe affinity across the CPUs that are
> online.

So, have you looked at tools/perf/util/cpumap.c? I think you can use:

int i;
struct cpu_map *cpus = cpu_map__new(NULL);

for (i = 0; i < cpus->nr; ++i) {
int cpu = cpus->map[i];
...
}

No?

- Arnaldo

> Signed-off-by: James Yang <james.yang@arm.com>
> Signed-off-by: Kim Phillips <kim.phillips@arm.com>
> ---
> tools/perf/bench/Build | 1 +
> tools/perf/bench/cpu-online-map.c | 21 +++++++++++++++++++++
> tools/perf/bench/cpu-online-map.h | 6 ++++++
> tools/perf/bench/futex-hash.c | 14 ++++++++++++--
> tools/perf/bench/futex-lock-pi.c | 15 ++++++++++++---
> tools/perf/bench/futex-requeue.c | 14 +++++++++++---
> tools/perf/bench/futex-wake-parallel.c | 17 ++++++++++++++---
> tools/perf/bench/futex-wake.c | 15 ++++++++++++---
> 8 files changed, 89 insertions(+), 14 deletions(-)
> create mode 100644 tools/perf/bench/cpu-online-map.c
> create mode 100644 tools/perf/bench/cpu-online-map.h
>
> diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
> index 60bf11943047..bc79d3577ace 100644
> --- a/tools/perf/bench/Build
> +++ b/tools/perf/bench/Build
> @@ -6,6 +6,7 @@ perf-y += futex-wake.o
> perf-y += futex-wake-parallel.o
> perf-y += futex-requeue.o
> perf-y += futex-lock-pi.o
> +perf-y += cpu-online-map.o
>
> perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
> perf-$(CONFIG_X86_64) += mem-memset-x86-64-asm.o
> diff --git a/tools/perf/bench/cpu-online-map.c b/tools/perf/bench/cpu-online-map.c
> new file mode 100644
> index 000000000000..4157d2220bf4
> --- /dev/null
> +++ b/tools/perf/bench/cpu-online-map.c
> @@ -0,0 +1,21 @@
> +#include <sched.h>
> +#include <unistd.h>
> +#include <err.h>
> +#include <stdlib.h>
> +#include "cpu-online-map.h"
> +
> +void compute_cpu_online_map(int *cpu_online_map)
> +{
> + long ncpus_conf = sysconf(_SC_NPROCESSORS_CONF);
> + cpu_set_t set;
> + size_t j = 0;
> +
> + CPU_ZERO(&set);
> +
> + if (sched_getaffinity(0, sizeof(set), &set))
> + err(EXIT_FAILURE, "sched_getaffinity");
> +
> + for (int i = 0; i < ncpus_conf; i++)
> + if (CPU_ISSET(i, &set))
> + cpu_online_map[j++] = i;
> +}
> diff --git a/tools/perf/bench/cpu-online-map.h b/tools/perf/bench/cpu-online-map.h
> new file mode 100644
> index 000000000000..0620a674c6d8
> --- /dev/null
> +++ b/tools/perf/bench/cpu-online-map.h
> @@ -0,0 +1,6 @@
> +#ifndef CPU_ONLINE_MAP_H
> +#define CPU_ONLINE_MAP_H
> +
> +void compute_cpu_online_map(int *cpu_online_map);
> +
> +#endif
> diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
> index 58ae6ed8f38b..81314eea1cf5 100644
> --- a/tools/perf/bench/futex-hash.c
> +++ b/tools/perf/bench/futex-hash.c
> @@ -24,6 +24,7 @@
> #include <subcmd/parse-options.h>
> #include "bench.h"
> #include "futex.h"
> +#include "cpu-online-map.h"
>
> #include <err.h>
> #include <sys/time.h>
> @@ -120,9 +121,11 @@ int bench_futex_hash(int argc, const char **argv)
> int ret = 0;
> cpu_set_t cpu;
> struct sigaction act;
> - unsigned int i, ncpus;
> + unsigned int i;
> + long ncpus;
> pthread_attr_t thread_attr;
> struct worker *worker = NULL;
> + int *cpu_map;
>
> argc = parse_options(argc, argv, options, bench_futex_hash_usage, 0);
> if (argc) {
> @@ -132,6 +135,12 @@ int bench_futex_hash(int argc, const char **argv)
>
> ncpus = sysconf(_SC_NPROCESSORS_ONLN);
>
> + cpu_map = calloc(ncpus, sizeof(int));
> + if (!cpu_map)
> + goto errmem;
> +
> + compute_cpu_online_map(cpu_map);
> +
> sigfillset(&act.sa_mask);
> act.sa_sigaction = toggle_done;
> sigaction(SIGINT, &act, NULL);
> @@ -164,7 +173,7 @@ int bench_futex_hash(int argc, const char **argv)
> goto errmem;
>
> CPU_ZERO(&cpu);
> - CPU_SET(i % ncpus, &cpu);
> + CPU_SET(cpu_map[i % ncpus], &cpu);
>
> ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu);
> if (ret)
> @@ -217,6 +226,7 @@ int bench_futex_hash(int argc, const char **argv)
> print_summary();
>
> free(worker);
> + free(cpu_map);
> return ret;
> errmem:
> err(EXIT_FAILURE, "calloc");
> diff --git a/tools/perf/bench/futex-lock-pi.c b/tools/perf/bench/futex-lock-pi.c
> index 08653ae8a8c4..42ab351b2c50 100644
> --- a/tools/perf/bench/futex-lock-pi.c
> +++ b/tools/perf/bench/futex-lock-pi.c
> @@ -15,6 +15,7 @@
> #include <errno.h>
> #include "bench.h"
> #include "futex.h"
> +#include "cpu-online-map.h"
>
> #include <err.h>
> #include <stdlib.h>
> @@ -113,7 +114,8 @@ static void *workerfn(void *arg)
> return NULL;
> }
>
> -static void create_threads(struct worker *w, pthread_attr_t thread_attr)
> +static void create_threads(struct worker *w, pthread_attr_t thread_attr,
> + int *cpu_map)
> {
> cpu_set_t cpu;
> unsigned int i;
> @@ -131,7 +133,7 @@ static void create_threads(struct worker *w, pthread_attr_t thread_attr)
> worker[i].futex = &global_futex;
>
> CPU_ZERO(&cpu);
> - CPU_SET(i % ncpus, &cpu);
> + CPU_SET(cpu_map[i % ncpus], &cpu);
>
> if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu))
> err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
> @@ -147,12 +149,18 @@ int bench_futex_lock_pi(int argc, const char **argv)
> unsigned int i;
> struct sigaction act;
> pthread_attr_t thread_attr;
> + int *cpu_map;
>
> argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0);
> if (argc)
> goto err;
>
> ncpus = sysconf(_SC_NPROCESSORS_ONLN);
> + cpu_map = calloc(ncpus, sizeof(int));
> + if (!cpu_map)
> + err(EXIT_FAILURE, "calloc");
> +
> + compute_cpu_online_map(cpu_map);
>
> sigfillset(&act.sa_mask);
> act.sa_sigaction = toggle_done;
> @@ -180,7 +188,7 @@ int bench_futex_lock_pi(int argc, const char **argv)
> pthread_attr_init(&thread_attr);
> gettimeofday(&start, NULL);
>
> - create_threads(worker, thread_attr);
> + create_threads(worker, thread_attr, cpu_map);
> pthread_attr_destroy(&thread_attr);
>
> pthread_mutex_lock(&thread_lock);
> @@ -218,6 +226,7 @@ int bench_futex_lock_pi(int argc, const char **argv)
> print_summary();
>
> free(worker);
> + free(cpu_map);
> return ret;
> err:
> usage_with_options(bench_futex_lock_pi_usage, options);
> diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
> index 1058c194608a..366961b901c6 100644
> --- a/tools/perf/bench/futex-requeue.c
> +++ b/tools/perf/bench/futex-requeue.c
> @@ -22,6 +22,7 @@
> #include <errno.h>
> #include "bench.h"
> #include "futex.h"
> +#include "cpu-online-map.h"
>
> #include <err.h>
> #include <stdlib.h>
> @@ -83,7 +84,7 @@ static void *workerfn(void *arg __maybe_unused)
> }
>
> static void block_threads(pthread_t *w,
> - pthread_attr_t thread_attr)
> + pthread_attr_t thread_attr, int *cpu_map)
> {
> cpu_set_t cpu;
> unsigned int i;
> @@ -93,7 +94,7 @@ static void block_threads(pthread_t *w,
> /* create and block all threads */
> for (i = 0; i < nthreads; i++) {
> CPU_ZERO(&cpu);
> - CPU_SET(i % ncpus, &cpu);
> + CPU_SET(cpu_map[i % ncpus], &cpu);
>
> if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu))
> err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
> @@ -116,12 +117,18 @@ int bench_futex_requeue(int argc, const char **argv)
> unsigned int i, j;
> struct sigaction act;
> pthread_attr_t thread_attr;
> + int *cpu_map;
>
> argc = parse_options(argc, argv, options, bench_futex_requeue_usage, 0);
> if (argc)
> goto err;
>
> ncpus = sysconf(_SC_NPROCESSORS_ONLN);
> + cpu_map = calloc(ncpus, sizeof(int));
> + if (!cpu_map)
> + err(EXIT_FAILURE, "calloc");
> +
> + compute_cpu_online_map(cpu_map);
>
> sigfillset(&act.sa_mask);
> act.sa_sigaction = toggle_done;
> @@ -156,7 +163,7 @@ int bench_futex_requeue(int argc, const char **argv)
> struct timeval start, end, runtime;
>
> /* create, launch & block all threads */
> - block_threads(worker, thread_attr);
> + block_threads(worker, thread_attr, cpu_map);
>
> /* make sure all threads are already blocked */
> pthread_mutex_lock(&thread_lock);
> @@ -210,6 +217,7 @@ int bench_futex_requeue(int argc, const char **argv)
> print_summary();
>
> free(worker);
> + free(cpu_map);
> return ret;
> err:
> usage_with_options(bench_futex_requeue_usage, options);
> diff --git a/tools/perf/bench/futex-wake-parallel.c b/tools/perf/bench/futex-wake-parallel.c
> index b4732dad9f89..5617bcd17e55 100644
> --- a/tools/perf/bench/futex-wake-parallel.c
> +++ b/tools/perf/bench/futex-wake-parallel.c
> @@ -21,6 +21,7 @@
> #include <errno.h>
> #include "bench.h"
> #include "futex.h"
> +#include "cpu-online-map.h"
>
> #include <err.h>
> #include <stdlib.h>
> @@ -119,7 +120,8 @@ static void *blocked_workerfn(void *arg __maybe_unused)
> return NULL;
> }
>
> -static void block_threads(pthread_t *w, pthread_attr_t thread_attr)
> +static void block_threads(pthread_t *w, pthread_attr_t thread_attr,
> + int *cpu_map)
> {
> cpu_set_t cpu;
> unsigned int i;
> @@ -129,7 +131,7 @@ static void block_threads(pthread_t *w, pthread_attr_t thread_attr)
> /* create and block all threads */
> for (i = 0; i < nblocked_threads; i++) {
> CPU_ZERO(&cpu);
> - CPU_SET(i % ncpus, &cpu);
> + CPU_SET(cpu_map[i % ncpus], &cpu);
>
> if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu))
> err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
> @@ -205,6 +207,7 @@ int bench_futex_wake_parallel(int argc, const char **argv)
> struct sigaction act;
> pthread_attr_t thread_attr;
> struct thread_data *waking_worker;
> + int *cpu_map;
>
> argc = parse_options(argc, argv, options,
> bench_futex_wake_parallel_usage, 0);
> @@ -218,6 +221,13 @@ int bench_futex_wake_parallel(int argc, const char **argv)
> sigaction(SIGINT, &act, NULL);
>
> ncpus = sysconf(_SC_NPROCESSORS_ONLN);
> +
> + cpu_map = calloc(ncpus, sizeof(int));
> + if (!cpu_map)
> + err(EXIT_FAILURE, "calloc");
> +
> + compute_cpu_online_map(cpu_map);
> +
> if (!nblocked_threads)
> nblocked_threads = ncpus;
>
> @@ -259,7 +269,7 @@ int bench_futex_wake_parallel(int argc, const char **argv)
> err(EXIT_FAILURE, "calloc");
>
> /* create, launch & block all threads */
> - block_threads(blocked_worker, thread_attr);
> + block_threads(blocked_worker, thread_attr, cpu_map);
>
> /* make sure all threads are already blocked */
> pthread_mutex_lock(&thread_lock);
> @@ -295,5 +305,6 @@ int bench_futex_wake_parallel(int argc, const char **argv)
> print_summary();
>
> free(blocked_worker);
> + free(cpu_map);
> return ret;
> }
> diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
> index 8c5c0b6b5c97..c0c71a769d2f 100644
> --- a/tools/perf/bench/futex-wake.c
> +++ b/tools/perf/bench/futex-wake.c
> @@ -22,6 +22,7 @@
> #include <errno.h>
> #include "bench.h"
> #include "futex.h"
> +#include "cpu-online-map.h"
>
> #include <err.h>
> #include <stdlib.h>
> @@ -89,7 +90,7 @@ static void print_summary(void)
> }
>
> static void block_threads(pthread_t *w,
> - pthread_attr_t thread_attr)
> + pthread_attr_t thread_attr, int *cpu_map)
> {
> cpu_set_t cpu;
> unsigned int i;
> @@ -99,7 +100,7 @@ static void block_threads(pthread_t *w,
> /* create and block all threads */
> for (i = 0; i < nthreads; i++) {
> CPU_ZERO(&cpu);
> - CPU_SET(i % ncpus, &cpu);
> + CPU_SET(cpu_map[i % ncpus], &cpu);
>
> if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu))
> err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
> @@ -122,6 +123,7 @@ int bench_futex_wake(int argc, const char **argv)
> unsigned int i, j;
> struct sigaction act;
> pthread_attr_t thread_attr;
> + int *cpu_map;
>
> argc = parse_options(argc, argv, options, bench_futex_wake_usage, 0);
> if (argc) {
> @@ -131,6 +133,12 @@ int bench_futex_wake(int argc, const char **argv)
>
> ncpus = sysconf(_SC_NPROCESSORS_ONLN);
>
> + cpu_map = calloc(ncpus, sizeof(int));
> + if (! cpu_map)
> + err(EXIT_FAILURE, "calloc");
> +
> + compute_cpu_online_map(cpu_map);
> +
> sigfillset(&act.sa_mask);
> act.sa_sigaction = toggle_done;
> sigaction(SIGINT, &act, NULL);
> @@ -161,7 +169,7 @@ int bench_futex_wake(int argc, const char **argv)
> struct timeval start, end, runtime;
>
> /* create, launch & block all threads */
> - block_threads(worker, thread_attr);
> + block_threads(worker, thread_attr, cpu_map);
>
> /* make sure all threads are already blocked */
> pthread_mutex_lock(&thread_lock);
> @@ -204,5 +212,6 @@ int bench_futex_wake(int argc, const char **argv)
> print_summary();
>
> free(worker);
> + free(cpu_map);
> return ret;
> }
> --
> 2.15.0