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perf bench futex: Use cpumaps

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It was reported that the whole futex bench breaks when dealing with
non-contiguously numbered cpus.

$ echo 0 | sudo tee /sys/devices/system/cpu/cpu3/online
$ ./perf bench futex all
 perf: pthread_create: Operation not permitted
 Run summary [PID 14934]: 7 threads, each ....

James had implemented an approach with cpumaps that use an in house
flavor. Instead of re-inventing the wheel, I've redone the patch such
that we use the perf's util/cpumap.c interface instead.

Applies to all futex benchmarks.

Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Originally-from: James Yang <james.yang@arm.com>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Kim Phillips <kim.phillips@arm.com>
Link: http://lkml.kernel.org/r/20171127042101.3659-2-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Davidlohr Bueso
2017-11-26 20:20:59 -08:00
committed by Arnaldo Carvalho de Melo
parent 17a68b8359
commit 3b2323c2c1
5 changed files with 65 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
tools/perf/bench/futex-hash.c
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@@ -24,6 +24,7 @@
#include <subcmd/parse-options.h>
#include "bench.h"
#include "futex.h"
#include "cpumap.h"
#include <err.h>
#include <sys/time.h>
@@ -118,11 +119,12 @@ static void print_summary(void)
int bench_futex_hash(int argc, const char **argv)
{
int ret = 0;
cpu_set_t cpu;
cpu_set_t cpuset;
struct sigaction act;
unsigned int i, ncpus;
unsigned int i;
pthread_attr_t thread_attr;
struct worker *worker = NULL;
struct cpu_map *cpu;
argc = parse_options(argc, argv, options, bench_futex_hash_usage, 0);
if (argc) {
@@ -130,14 +132,16 @@ int bench_futex_hash(int argc, const char **argv)
exit(EXIT_FAILURE);
}
ncpus = sysconf(_SC_NPROCESSORS_ONLN);
cpu = cpu_map__new(NULL);
if (!cpu)
goto errmem;
sigfillset(&act.sa_mask);
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);
if (!nthreads) /* default to the number of CPUs */
nthreads = ncpus;
nthreads = cpu->nr;
worker = calloc(nthreads, sizeof(*worker));
if (!worker)
@@ -163,10 +167,10 @@ int bench_futex_hash(int argc, const char **argv)
if (!worker[i].futex)
goto errmem;
CPU_ZERO(&cpu);
CPU_SET(i % ncpus, &cpu);
CPU_ZERO(&cpuset);
CPU_SET(cpu->map[i % cpu->nr], &cpuset);
ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu);
ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset);
if (ret)
err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
@@ -217,6 +221,7 @@ int bench_futex_hash(int argc, const char **argv)
print_summary();
free(worker);
free(cpu);
return ret;
errmem:
err(EXIT_FAILURE, "calloc");