1 files changed, 35 insertions, 19 deletions

diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index f78bab0f3d45..40af7f67c407 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -36,6 +36,7 @@
 
 #include "uffd-common.h"
 
+uint64_t features;
 #ifdef __NR_userfaultfd
 
 #define BOUNCE_RANDOM		(1<<0)
@@ -179,12 +180,12 @@ static void *background_thread(void *arg)
 static int stress(struct uffd_args *args)
 {
 	unsigned long cpu;
-	pthread_t locking_threads[nr_cpus];
-	pthread_t uffd_threads[nr_cpus];
-	pthread_t background_threads[nr_cpus];
+	pthread_t locking_threads[nr_parallel];
+	pthread_t uffd_threads[nr_parallel];
+	pthread_t background_threads[nr_parallel];
 
 	finished = 0;
-	for (cpu = 0; cpu < nr_cpus; cpu++) {
+	for (cpu = 0; cpu < nr_parallel; cpu++) {
 		if (pthread_create(&locking_threads[cpu], &attr,
 				   locking_thread, (void *)cpu))
 			return 1;
@@ -202,7 +203,7 @@ static int stress(struct uffd_args *args)
 				   background_thread, (void *)cpu))
 			return 1;
 	}
-	for (cpu = 0; cpu < nr_cpus; cpu++)
+	for (cpu = 0; cpu < nr_parallel; cpu++)
 		if (pthread_join(background_threads[cpu], NULL))
 			return 1;
 
@@ -218,11 +219,11 @@ static int stress(struct uffd_args *args)
 	uffd_test_ops->release_pages(area_src);
 
 	finished = 1;
-	for (cpu = 0; cpu < nr_cpus; cpu++)
+	for (cpu = 0; cpu < nr_parallel; cpu++)
 		if (pthread_join(locking_threads[cpu], NULL))
 			return 1;
 
-	for (cpu = 0; cpu < nr_cpus; cpu++) {
+	for (cpu = 0; cpu < nr_parallel; cpu++) {
 		char c;
 		if (bounces & BOUNCE_POLL) {
 			if (write(pipefd[cpu*2+1], &c, 1) != 1)
@@ -245,12 +246,16 @@ static int userfaultfd_stress(void)
 {
 	void *area;
 	unsigned long nr;
-	struct uffd_args args[nr_cpus];
+	struct uffd_args args[nr_parallel];
 	uint64_t mem_size = nr_pages * page_size;
+	int flags = 0;
 
-	memset(args, 0, sizeof(struct uffd_args) * nr_cpus);
+	memset(args, 0, sizeof(struct uffd_args) * nr_parallel);
 
-	if (uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED, NULL))
+	if (features & UFFD_FEATURE_WP_UNPOPULATED && test_type == TEST_ANON)
+		flags = UFFD_FEATURE_WP_UNPOPULATED;
+
+	if (uffd_test_ctx_init(flags, NULL))
 		err("context init failed");
 
 	if (posix_memalign(&area, page_size, page_size))
@@ -320,7 +325,7 @@ static int userfaultfd_stress(void)
 		 */
 		uffd_test_ops->release_pages(area_dst);
 
-		uffd_stats_reset(args, nr_cpus);
+		uffd_stats_reset(args, nr_parallel);
 
 		/* bounce pass */
 		if (stress(args)) {
@@ -354,7 +359,7 @@ static int userfaultfd_stress(void)
 
 		swap(area_src_alias, area_dst_alias);
 
-		uffd_stats_report(args, nr_cpus);
+		uffd_stats_report(args, nr_parallel);
 	}
 	uffd_test_ctx_clear();
 
@@ -385,8 +390,6 @@ static void set_test_type(const char *type)
 
 static void parse_test_type_arg(const char *raw_type)
 {
-	uint64_t features = UFFD_API_FEATURES;
-
 	set_test_type(raw_type);
 
 	if (!test_type)
@@ -409,12 +412,15 @@ static void parse_test_type_arg(const char *raw_type)
 	 * feature.
 	 */
 
-	if (userfaultfd_open(&features))
-		err("Userfaultfd open failed");
+	if (uffd_get_features(&features) && errno == ENOENT)
+		ksft_exit_skip("failed to get available features (%d)\n", errno);
 
 	test_uffdio_wp = test_uffdio_wp &&
 		(features & UFFD_FEATURE_PAGEFAULT_FLAG_WP);
 
+	if (test_type != TEST_ANON && !(features & UFFD_FEATURE_WP_HUGETLBFS_SHMEM))
+		test_uffdio_wp = false;
+
 	close(uffd);
 	uffd = -1;
 }
@@ -429,6 +435,7 @@ static void sigalrm(int sig)
 
 int main(int argc, char **argv)
 {
+	unsigned long nr_cpus;
 	size_t bytes;
 
 	if (argc < 4)
@@ -448,10 +455,19 @@ int main(int argc, char **argv)
 	}
 
 	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+	if (nr_cpus > 32) {
+		/* Don't let calculation below go to zero. */
+		ksft_print_msg("_SC_NPROCESSORS_ONLN (%lu) too large, capping nr_threads to 32\n",
+			       nr_cpus);
+		nr_parallel = 32;
+	} else {
+		nr_parallel = nr_cpus;
+	}
 
-	nr_pages_per_cpu = bytes / page_size / nr_cpus;
+	nr_pages_per_cpu = bytes / page_size / nr_parallel;
 	if (!nr_pages_per_cpu) {
-		_err("invalid MiB");
+		_err("pages_per_cpu = 0, cannot test (%lu / %lu / %lu)",
+			bytes, page_size, nr_parallel);
 		usage();
 	}
 
@@ -460,7 +476,7 @@ int main(int argc, char **argv)
 		_err("invalid bounces");
 		usage();
 	}
-	nr_pages = nr_pages_per_cpu * nr_cpus;
+	nr_pages = nr_pages_per_cpu * nr_parallel;
 
 	printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n",
 	       nr_pages, nr_pages_per_cpu);