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

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

Em Thu, Nov 23, 2017 at 12:09:48PM -0300, Arnaldo Carvalho de Melo escreveu:
> 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?

But then, this can be done later, as probably will result in more
changes, I'm continuing to review the other patches.

- Arnaldo

> - 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