Commit c9c2a427 authored by Athira Rajeev's avatar Athira Rajeev Committed by Arnaldo Carvalho de Melo
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perf bench: Fix futex bench to correct usage of affinity for machines with #CPUs > 1K 



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: default avatarDisha Goel <disgoel@linux.vnet.ibm.com>
Reviewed-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: default avatarAthira Jajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: default avatarDisha Goel <disgoel@linux.vnet.ibm.com>
Acked-by: default avatarIan 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent aeee9dc5

tools/perf/bench/futex-hash.c

+19 −7
Original line number Diff line number Diff line
@@ -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);

tools/perf/bench/futex-lock-pi.c

+16 −5
Original line number Diff line number Diff line
@@ -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;
@@ -135,16 +141,21 @@ 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)

{

tools/perf/bench/futex-requeue.c

+16 −5
Original line number Diff line number Diff line
@@ -123,23 +123,34 @@ 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,

			siginfo_t *info __maybe_unused,

tools/perf/bench/futex-wake-parallel.c

+16 −5
Original line number Diff line number Diff line
@@ -144,23 +144,34 @@ 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)

{

tools/perf/bench/futex-wake.c

+16 −6
Original line number Diff line number Diff line
@@ -97,23 +97,33 @@ 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,

			siginfo_t *info __maybe_unused,