perf bench: Fix futex bench to correct usage of affinity for machines with #CPUs...

The 'perf bench futex' testcase fails on systems with more than 1K CPUs.

Testcase: perf bench futex all

Failure snippet:
<<>>Running futex/hash benchmark...

perf: pthread_create: No such file or directory
<<>>

All the futex benchmarks (ie hash, lock-api, requeue, wake,
wake-parallel), pthread_create is invoked in respective bench_futex_*
function. Though the logs shows direct failure from pthread_create,
strace logs showed that actual failure is from  "sched_setaffinity"
returning EINVAL (invalid argument).

This happens because the default mask size in glibc is 1024. To overcome
this 1024 CPUs mask size limitation of cpu_set_t, change the mask size
using the CPU_*_S macros.

Patch addresses this by fixing all the futex benchmarks to use CPU_ALLOC
to allocate cpumask, CPU_ALLOC_SIZE for size, and CPU_SET_S to set the
mask.

Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20220406175113.87881-2-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
index dbcecec..f05db4c 100644 (file)
--- a/tools/perf/bench/futex-hash.c
+++ b/tools/perf/bench/futex-hash.c
@@ -122,12 +122,14 @@ static void print_summary(void)
 int bench_futex_hash(int argc, const char **argv)
 {
        int ret = 0;
-       cpu_set_t cpuset;
+       cpu_set_t *cpuset;
        struct sigaction act;
        unsigned int i;
        pthread_attr_t thread_attr;
        struct worker *worker = NULL;
        struct perf_cpu_map *cpu;
+       int nrcpus;
+       size_t size;
 
        argc = parse_options(argc, argv, options, bench_futex_hash_usage, 0);
        if (argc) {
@@ -170,25 +172,35 @@ int bench_futex_hash(int argc, const char **argv)
        threads_starting = params.nthreads;
        pthread_attr_init(&thread_attr);
        gettimeofday(&bench__start, NULL);
+
+       nrcpus = perf_cpu_map__nr(cpu);
+       cpuset = CPU_ALLOC(nrcpus);
+       BUG_ON(!cpuset);
+       size = CPU_ALLOC_SIZE(nrcpus);
+
        for (i = 0; i < params.nthreads; i++) {
                worker[i].tid = i;
                worker[i].futex = calloc(params.nfutexes, sizeof(*worker[i].futex));
                if (!worker[i].futex)
                        goto errmem;
 
-               CPU_ZERO(&cpuset);
-               CPU_SET(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, &cpuset);
+               CPU_ZERO_S(size, cpuset);
 
-               ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset);
-               if (ret)
+               CPU_SET_S(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, size, cpuset);
+               ret = pthread_attr_setaffinity_np(&thread_attr, size, cpuset);
+               if (ret) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
-
+               }
                ret = pthread_create(&worker[i].thread, &thread_attr, workerfn,
                                     (void *)(struct worker *) &worker[i]);
-               if (ret)
+               if (ret) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_create");
+               }
 
        }
+       CPU_FREE(cpuset);
        pthread_attr_destroy(&thread_attr);
 
        pthread_mutex_lock(&thread_lock);

diff --git a/tools/perf/bench/futex-lock-pi.c b/tools/perf/bench/futex-lock-pi.c
index 6fc9a3d..0abb3f7 100644 (file)
--- a/tools/perf/bench/futex-lock-pi.c
+++ b/tools/perf/bench/futex-lock-pi.c
@@ -120,11 +120,17 @@ static void *workerfn(void *arg)
 static void create_threads(struct worker *w, pthread_attr_t thread_attr,
                           struct perf_cpu_map *cpu)
 {
-       cpu_set_t cpuset;
+       cpu_set_t *cpuset;
        unsigned int i;
+       int nrcpus =  perf_cpu_map__nr(cpu);
+       size_t size;
 
        threads_starting = params.nthreads;
 
+       cpuset = CPU_ALLOC(nrcpus);
+       BUG_ON(!cpuset);
+       size = CPU_ALLOC_SIZE(nrcpus);
+
        for (i = 0; i < params.nthreads; i++) {
                worker[i].tid = i;
 
@@ -135,15 +141,20 @@ static void create_threads(struct worker *w, pthread_attr_t thread_attr,
                } else
                        worker[i].futex = &global_futex;
 
-               CPU_ZERO(&cpuset);
-               CPU_SET(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, &cpuset);
+               CPU_ZERO_S(size, cpuset);
+               CPU_SET_S(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, size, cpuset);
 
-               if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
+               if (pthread_attr_setaffinity_np(&thread_attr, size, cpuset)) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+               }
 
-               if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i]))
+               if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i])) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_create");
+               }
        }
+       CPU_FREE(cpuset);
 }
 
 int bench_futex_lock_pi(int argc, const char **argv)

diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
index 2f59d5d..b6faabf 100644 (file)
--- a/tools/perf/bench/futex-requeue.c
+++ b/tools/perf/bench/futex-requeue.c
@@ -123,22 +123,33 @@ static void *workerfn(void *arg __maybe_unused)
 static void block_threads(pthread_t *w,
                          pthread_attr_t thread_attr, struct perf_cpu_map *cpu)
 {
-       cpu_set_t cpuset;
+       cpu_set_t *cpuset;
        unsigned int i;
+       int nrcpus = perf_cpu_map__nr(cpu);
+       size_t size;
 
        threads_starting = params.nthreads;
 
+       cpuset = CPU_ALLOC(nrcpus);
+       BUG_ON(!cpuset);
+       size = CPU_ALLOC_SIZE(nrcpus);
+
        /* create and block all threads */
        for (i = 0; i < params.nthreads; i++) {
-               CPU_ZERO(&cpuset);
-               CPU_SET(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, &cpuset);
+               CPU_ZERO_S(size, cpuset);
+               CPU_SET_S(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, size, cpuset);
 
-               if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
+               if (pthread_attr_setaffinity_np(&thread_attr, size, cpuset)) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+               }
 
-               if (pthread_create(&w[i], &thread_attr, workerfn, NULL))
+               if (pthread_create(&w[i], &thread_attr, workerfn, NULL)) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_create");
+               }
        }
+       CPU_FREE(cpuset);
 }
 
 static void toggle_done(int sig __maybe_unused,

diff --git a/tools/perf/bench/futex-wake-parallel.c b/tools/perf/bench/futex-wake-parallel.c
index 861deb9..e47f46a 100644 (file)
--- a/tools/perf/bench/futex-wake-parallel.c
+++ b/tools/perf/bench/futex-wake-parallel.c
@@ -144,22 +144,33 @@ static void *blocked_workerfn(void *arg __maybe_unused)
 static void block_threads(pthread_t *w, pthread_attr_t thread_attr,
                          struct perf_cpu_map *cpu)
 {
-       cpu_set_t cpuset;
+       cpu_set_t *cpuset;
        unsigned int i;
+       int nrcpus = perf_cpu_map__nr(cpu);
+       size_t size;
 
        threads_starting = params.nthreads;
 
+       cpuset = CPU_ALLOC(nrcpus);
+       BUG_ON(!cpuset);
+       size = CPU_ALLOC_SIZE(nrcpus);
+
        /* create and block all threads */
        for (i = 0; i < params.nthreads; i++) {
-               CPU_ZERO(&cpuset);
-               CPU_SET(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, &cpuset);
+               CPU_ZERO_S(size, cpuset);
+               CPU_SET_S(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, size, cpuset);
 
-               if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
+               if (pthread_attr_setaffinity_np(&thread_attr, size, cpuset)) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+               }
 
-               if (pthread_create(&w[i], &thread_attr, blocked_workerfn, NULL))
+               if (pthread_create(&w[i], &thread_attr, blocked_workerfn, NULL)) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_create");
+               }
        }
+       CPU_FREE(cpuset);
 }
 
 static void print_run(struct thread_data *waking_worker, unsigned int run_num)

diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
index cfda48b..201a355 100644 (file)
--- a/tools/perf/bench/futex-wake.c
+++ b/tools/perf/bench/futex-wake.c
@@ -97,22 +97,32 @@ static void print_summary(void)
 static void block_threads(pthread_t *w,
                          pthread_attr_t thread_attr, struct perf_cpu_map *cpu)
 {
-       cpu_set_t cpuset;
+       cpu_set_t *cpuset;
        unsigned int i;
-
+       size_t size;
+       int nrcpus = perf_cpu_map__nr(cpu);
        threads_starting = params.nthreads;
 
+       cpuset = CPU_ALLOC(nrcpus);
+       BUG_ON(!cpuset);
+       size = CPU_ALLOC_SIZE(nrcpus);
+
        /* create and block all threads */
        for (i = 0; i < params.nthreads; i++) {
-               CPU_ZERO(&cpuset);
-               CPU_SET(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, &cpuset);
+               CPU_ZERO_S(size, cpuset);
+               CPU_SET_S(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, size, cpuset);
 
-               if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
+               if (pthread_attr_setaffinity_np(&thread_attr, size, cpuset)) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+               }
 
-               if (pthread_create(&w[i], &thread_attr, workerfn, NULL))
+               if (pthread_create(&w[i], &thread_attr, workerfn, NULL)) {
+                       CPU_FREE(cpuset);
                        err(EXIT_FAILURE, "pthread_create");
+               }
        }
+       CPU_FREE(cpuset);
 }
 
 static void toggle_done(int sig __maybe_unused,