I never had much luck running mm selftests so I spent a few hours digging into why.
Looks like most of the reason is missing SKIP checks, so this series is just adding a bunch of those that I found. I did not do anything like all of them, just the ones I spotted in gup_longterm, gup_test, mmap, userfaultfd and memfd_secret.
It's a bit unfortunate to have to skip those tests when ftruncate() fails, but I don't have time to dig deep enough into it to actually make them pass. I have observed the issue on 9pfs and heard rumours that NFS has a similar problem.
I'm now able to run these test groups successfully:
- mmap - gup_test - compaction - migration - page_frag - userfaultfd
Signed-off-by: Brendan Jackman jackmanb@google.com --- Changes in v3: - Added fix for userfaultfd tests. - Dropped attempts to use sudo. - Fixed garbage printf in uffd-stress. (Added EXTRA_CFLAGS=-Werror FORCE_TARGETS=1 to my scripts to prevent such errors happening again). - Fixed missing newlines in ksft_test_result_skip() calls. - Link to v2: https://lore.kernel.org/r/20250221-mm-selftests-v2-0-28c4d66383c5@google.com
Changes in v2 (Thanks to Dev for the reviews): - Improve and cleanup some error messages - Add some extra SKIPs - Fix misnaming of nr_cpus variable in uffd tests - Link to v1: https://lore.kernel.org/r/20250220-mm-selftests-v1-0-9bbf57d64463@google.com
--- Brendan Jackman (10): selftests/mm: Report errno when things fail in gup_longterm selftests/mm: Skip uffd-stress if userfaultfd not available selftests/mm: Skip uffd-wp-mremap if userfaultfd not available selftests/mm/uffd: Rename nr_cpus -> nr_threads selftests/mm: Print some details when uffd-stress gets bad params selftests/mm: Don't fail uffd-stress if too many CPUs selftests/mm: Skip map_populate on weird filesystems selftests/mm: Skip gup_longerm tests on weird filesystems selftests/mm: Drop unnecessary sudo usage selftests/mm: Ensure uffd-wp-mremap gets pages of each size
tools/testing/selftests/mm/gup_longterm.c | 45 ++++++++++++++++++---------- tools/testing/selftests/mm/map_populate.c | 7 +++++ tools/testing/selftests/mm/run_vmtests.sh | 25 ++++++++++++++-- tools/testing/selftests/mm/uffd-common.c | 8 ++--- tools/testing/selftests/mm/uffd-common.h | 2 +- tools/testing/selftests/mm/uffd-stress.c | 42 ++++++++++++++++---------- tools/testing/selftests/mm/uffd-unit-tests.c | 2 +- tools/testing/selftests/mm/uffd-wp-mremap.c | 5 +++- 8 files changed, 95 insertions(+), 41 deletions(-) --- base-commit: 76544811c850a1f4c055aa182b513b7a843868ea change-id: 20250220-mm-selftests-2d7d0542face
Best regards,
Just reporting failure doesn't tell you what went wrong. This can fail in different ways so report errno to help the reader get started debugging.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/gup_longterm.c | 37 ++++++++++++++++++------------- 1 file changed, 21 insertions(+), 16 deletions(-)
diff --git a/tools/testing/selftests/mm/gup_longterm.c b/tools/testing/selftests/mm/gup_longterm.c index 9423ad439a6140163bdef2974615bb86406a8c14..879e9e4e8cce8127656fabe098abf7db5f6c5e23 100644 --- a/tools/testing/selftests/mm/gup_longterm.c +++ b/tools/testing/selftests/mm/gup_longterm.c @@ -96,13 +96,13 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared) int ret;
if (ftruncate(fd, size)) { - ksft_test_result_fail("ftruncate() failed\n"); + ksft_test_result_fail("ftruncate() failed (%s)\n", strerror(errno)); return; }
if (fallocate(fd, 0, 0, size)) { if (size == pagesize) - ksft_test_result_fail("fallocate() failed\n"); + ksft_test_result_fail("fallocate() failed (%s)\n", strerror(errno)); else ksft_test_result_skip("need more free huge pages\n"); return; @@ -112,7 +112,7 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared) shared ? MAP_SHARED : MAP_PRIVATE, fd, 0); if (mem == MAP_FAILED) { if (size == pagesize || shared) - ksft_test_result_fail("mmap() failed\n"); + ksft_test_result_fail("mmap() failed (%s)\n", strerror(errno)); else ksft_test_result_skip("need more free huge pages\n"); return; @@ -130,7 +130,7 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared) */ ret = mprotect(mem, size, PROT_READ); if (ret) { - ksft_test_result_fail("mprotect() failed\n"); + ksft_test_result_fail("mprotect() failed (%s)\n", strerror(errno)); goto munmap; } /* FALLTHROUGH */ @@ -165,18 +165,20 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared) args.flags |= rw ? PIN_LONGTERM_TEST_FLAG_USE_WRITE : 0; ret = ioctl(gup_fd, PIN_LONGTERM_TEST_START, &args); if (ret && errno == EINVAL) { - ksft_test_result_skip("PIN_LONGTERM_TEST_START failed\n"); + ksft_test_result_skip("PIN_LONGTERM_TEST_START failed (EINVAL)n"); break; } else if (ret && errno == EFAULT) { ksft_test_result(!should_work, "Should have failed\n"); break; } else if (ret) { - ksft_test_result_fail("PIN_LONGTERM_TEST_START failed\n"); + ksft_test_result_fail("PIN_LONGTERM_TEST_START failed (%s)\n", + strerror(errno)); break; }
if (ioctl(gup_fd, PIN_LONGTERM_TEST_STOP)) - ksft_print_msg("[INFO] PIN_LONGTERM_TEST_STOP failed\n"); + ksft_print_msg("[INFO] PIN_LONGTERM_TEST_STOP failed (%s)\n", + strerror(errno));
/* * TODO: if the kernel ever supports long-term R/W pinning on @@ -202,7 +204,8 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared) /* Skip on errors, as we might just lack kernel support. */ ret = io_uring_queue_init(1, &ring, 0); if (ret < 0) { - ksft_test_result_skip("io_uring_queue_init() failed\n"); + ksft_test_result_skip("io_uring_queue_init() failed (%s)\n", + strerror(errno)); break; } /* @@ -215,13 +218,15 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared) /* Only new kernels return EFAULT. */ if (ret && (errno == ENOSPC || errno == EOPNOTSUPP || errno == EFAULT)) { - ksft_test_result(!should_work, "Should have failed\n"); + ksft_test_result(!should_work, "Should have failed (%s)\n", + strerror(errno)); } else if (ret) { /* * We might just lack support or have insufficient * MEMLOCK limits. */ - ksft_test_result_skip("io_uring_register_buffers() failed\n"); + ksft_test_result_skip("io_uring_register_buffers() failed (%s)\n", + strerror(errno)); } else { ksft_test_result(should_work, "Should have worked\n"); io_uring_unregister_buffers(&ring); @@ -249,7 +254,7 @@ static void run_with_memfd(test_fn fn, const char *desc)
fd = memfd_create("test", 0); if (fd < 0) { - ksft_test_result_fail("memfd_create() failed\n"); + ksft_test_result_fail("memfd_create() failed (%s)\n", strerror(errno)); return; }
@@ -266,13 +271,13 @@ static void run_with_tmpfile(test_fn fn, const char *desc)
file = tmpfile(); if (!file) { - ksft_test_result_fail("tmpfile() failed\n"); + ksft_test_result_fail("tmpfile() failed (%s)\n", strerror(errno)); return; }
fd = fileno(file); if (fd < 0) { - ksft_test_result_fail("fileno() failed\n"); + ksft_test_result_fail("fileno() failed (%s)\n", strerror(errno)); goto close; }
@@ -290,12 +295,12 @@ static void run_with_local_tmpfile(test_fn fn, const char *desc)
fd = mkstemp(filename); if (fd < 0) { - ksft_test_result_fail("mkstemp() failed\n"); + ksft_test_result_fail("mkstemp() failed (%s)\n", strerror(errno)); return; }
if (unlink(filename)) { - ksft_test_result_fail("unlink() failed\n"); + ksft_test_result_fail("unlink() failed (%s)\n", strerror(errno)); goto close; }
@@ -317,7 +322,7 @@ static void run_with_memfd_hugetlb(test_fn fn, const char *desc,
fd = memfd_create("test", flags); if (fd < 0) { - ksft_test_result_skip("memfd_create() failed\n"); + ksft_test_result_skip("memfd_create() failed (%s)\n", strerror(errno)); return; }
On 28/02/25 10:24 pm, Brendan Jackman wrote:
Just reporting failure doesn't tell you what went wrong. This can fail in different ways so report errno to help the reader get started debugging.
Signed-off-by: Brendan Jackman jackmanb@google.com
Reviewed-by: Dev Jain dev.jain@arm.com
It's pretty obvious that the test wouldn't work if you don't have the feature enabled. But, it's still useful to SKIP instead of failing so the reader can immediately tell that this is the reason why.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/uffd-stress.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c index a4b83280998ab7ce8d31e91d8f9fbb47ef11d742..ed68436fac62c76e2ca7060c661487f2f8a6ab45 100644 --- a/tools/testing/selftests/mm/uffd-stress.c +++ b/tools/testing/selftests/mm/uffd-stress.c @@ -411,8 +411,8 @@ static void parse_test_type_arg(const char *raw_type) * feature. */
- if (uffd_get_features(&features)) - err("failed to get available features"); + 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);
On 28/02/25 10:24 pm, Brendan Jackman wrote:
It's pretty obvious that the test wouldn't work if you don't have the feature enabled. But, it's still useful to SKIP instead of failing so the reader can immediately tell that this is the reason why.
Signed-off-by: Brendan Jackman jackmanb@google.com
tools/testing/selftests/mm/uffd-stress.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c index a4b83280998ab7ce8d31e91d8f9fbb47ef11d742..ed68436fac62c76e2ca7060c661487f2f8a6ab45 100644 --- a/tools/testing/selftests/mm/uffd-stress.c +++ b/tools/testing/selftests/mm/uffd-stress.c @@ -411,8 +411,8 @@ static void parse_test_type_arg(const char *raw_type) * feature. */
- if (uffd_get_features(&features))
err("failed to get available features");
- if (uffd_get_features(&features) && errno == ENOENT)
ksft_exit_skip("failed to get available features (%d)\n", errno);
Is it possible that uffd_get_features(&features) returns non-zero without errno == ENOENT?
It's obvious that this should fail in that case, but still, save the reader the effort of figuring out that they've run into this by just SKIPping
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/uffd-wp-mremap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/uffd-wp-mremap.c b/tools/testing/selftests/mm/uffd-wp-mremap.c index 2c4f984bd73caa17e12b9f4a5bb71e7fdf5d8554..c2ba7d46c7b4581a3c32a6b6acd148e3e89c2172 100644 --- a/tools/testing/selftests/mm/uffd-wp-mremap.c +++ b/tools/testing/selftests/mm/uffd-wp-mremap.c @@ -182,7 +182,10 @@ static void test_one_folio(size_t size, bool private, bool swapout, bool hugetlb
/* Register range for uffd-wp. */ if (userfaultfd_open(&features)) { - ksft_test_result_fail("userfaultfd_open() failed\n"); + if (errno == ENOENT) + ksft_test_result_skip("userfaultfd not available\n"); + else + ksft_test_result_fail("userfaultfd_open() failed\n"); goto out; } if (uffd_register(uffd, mem, size, false, true, false)) {
On 28/02/25 10:24 pm, Brendan Jackman wrote:
It's obvious that this should fail in that case, but still, save the reader the effort of figuring out that they've run into this by just SKIPping
Signed-off-by: Brendan Jackman jackmanb@google.com
tools/testing/selftests/mm/uffd-wp-mremap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/uffd-wp-mremap.c b/tools/testing/selftests/mm/uffd-wp-mremap.c index 2c4f984bd73caa17e12b9f4a5bb71e7fdf5d8554..c2ba7d46c7b4581a3c32a6b6acd148e3e89c2172 100644 --- a/tools/testing/selftests/mm/uffd-wp-mremap.c +++ b/tools/testing/selftests/mm/uffd-wp-mremap.c @@ -182,7 +182,10 @@ static void test_one_folio(size_t size, bool private, bool swapout, bool hugetlb /* Register range for uffd-wp. */ if (userfaultfd_open(&features)) {
ksft_test_result_fail("userfaultfd_open() failed\n");
if (errno == ENOENT)ksft_test_result_skip("userfaultfd not available\n");elseksft_test_result_fail("userfaultfd_open() failed\n");
I think you are correct, just want to confirm whether "uffd not available" if and only if "errno == ENOENT" is true. That is, is it possible that errno can be something else and uffd is still not available, or errno can be ENOENT even if uffd is available.
A later commit will bound this variable so it no longer necessarily matches the number of CPUs. Rename it appropriately.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/uffd-common.c | 8 ++++---- tools/testing/selftests/mm/uffd-common.h | 2 +- tools/testing/selftests/mm/uffd-stress.c | 28 ++++++++++++++-------------- tools/testing/selftests/mm/uffd-unit-tests.c | 2 +- 4 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index 717539eddf98754250e70e564cd9a59f398bd7ea..a72a2ed5e89480ed06c81b034967ed5ae5f8cad5 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -10,7 +10,7 @@ #define BASE_PMD_ADDR ((void *)(1UL << 30))
volatile bool test_uffdio_copy_eexist = true; -unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; +unsigned long nr_threads, nr_pages, nr_pages_per_cpu, page_size; char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap; int uffd = -1, uffd_flags, finished, *pipefd, test_type; bool map_shared; @@ -269,7 +269,7 @@ void uffd_test_ctx_clear(void) size_t i;
if (pipefd) { - for (i = 0; i < nr_cpus * 2; ++i) { + for (i = 0; i < nr_threads * 2; ++i) { if (close(pipefd[i])) err("close pipefd"); } @@ -365,10 +365,10 @@ int uffd_test_ctx_init(uint64_t features, const char **errmsg) */ uffd_test_ops->release_pages(area_dst);
- pipefd = malloc(sizeof(int) * nr_cpus * 2); + pipefd = malloc(sizeof(int) * nr_threads * 2); if (!pipefd) err("pipefd"); - for (cpu = 0; cpu < nr_cpus; cpu++) + for (cpu = 0; cpu < nr_threads; cpu++) if (pipe2(&pipefd[cpu * 2], O_CLOEXEC | O_NONBLOCK)) err("pipe");
diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h index a70ae10b5f6206daecc8e19ed3e3bbb388e265aa..604e3572fe17280ae346b031e2e867e039578f95 100644 --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -98,7 +98,7 @@ struct uffd_test_case_ops { }; typedef struct uffd_test_case_ops uffd_test_case_ops_t;
-extern unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; +extern unsigned long nr_threads, nr_pages, nr_pages_per_cpu, page_size; extern char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap; extern int uffd, uffd_flags, finished, *pipefd, test_type; extern bool map_shared; diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c index ed68436fac62c76e2ca7060c661487f2f8a6ab45..ec842bbb9f18e291fa51de0ed8d1fbf9aaf14372 100644 --- a/tools/testing/selftests/mm/uffd-stress.c +++ b/tools/testing/selftests/mm/uffd-stress.c @@ -179,12 +179,12 @@ 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_threads]; + pthread_t uffd_threads[nr_threads]; + pthread_t background_threads[nr_threads];
finished = 0; - for (cpu = 0; cpu < nr_cpus; cpu++) { + for (cpu = 0; cpu < nr_threads; cpu++) { if (pthread_create(&locking_threads[cpu], &attr, locking_thread, (void *)cpu)) return 1; @@ -202,7 +202,7 @@ 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_threads; cpu++) if (pthread_join(background_threads[cpu], NULL)) return 1;
@@ -218,11 +218,11 @@ 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_threads; cpu++) if (pthread_join(locking_threads[cpu], NULL)) return 1;
- for (cpu = 0; cpu < nr_cpus; cpu++) { + for (cpu = 0; cpu < nr_threads; cpu++) { char c; if (bounces & BOUNCE_POLL) { if (write(pipefd[cpu*2+1], &c, 1) != 1) @@ -245,11 +245,11 @@ static int userfaultfd_stress(void) { void *area; unsigned long nr; - struct uffd_args args[nr_cpus]; + struct uffd_args args[nr_threads]; 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_threads);
if (features & UFFD_FEATURE_WP_UNPOPULATED && test_type == TEST_ANON) flags = UFFD_FEATURE_WP_UNPOPULATED; @@ -324,7 +324,7 @@ static int userfaultfd_stress(void) */ uffd_test_ops->release_pages(area_dst);
- uffd_stats_reset(args, nr_cpus); + uffd_stats_reset(args, nr_threads);
/* bounce pass */ if (stress(args)) { @@ -358,7 +358,7 @@ static int userfaultfd_stress(void)
swap(area_src_alias, area_dst_alias);
- uffd_stats_report(args, nr_cpus); + uffd_stats_report(args, nr_threads); } uffd_test_ctx_clear();
@@ -452,9 +452,9 @@ int main(int argc, char **argv) return KSFT_SKIP; }
- nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); + nr_threads = sysconf(_SC_NPROCESSORS_ONLN);
- nr_pages_per_cpu = bytes / page_size / nr_cpus; + nr_pages_per_cpu = bytes / page_size / nr_threads; if (!nr_pages_per_cpu) { _err("invalid MiB"); usage(); @@ -465,7 +465,7 @@ 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_threads;
printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n", nr_pages, nr_pages_per_cpu); diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 9ff71fa1f9bf09b3ae599250663a25bbe2c13b8a..2f84fae5642c6f91b75fbf5f5d59ae64a1c15f92 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -197,7 +197,7 @@ uffd_setup_environment(uffd_test_args_t *args, uffd_test_case_t *test,
nr_pages = UFFD_TEST_MEM_SIZE / page_size; /* TODO: remove this global var.. it's so ugly */ - nr_cpus = 1; + nr_threads = 1;
/* Initialize test arguments */ args->mem_type = mem_type;
On 28/02/25 10:24 pm, Brendan Jackman wrote:
A later commit will bound this variable so it no longer necessarily matches the number of CPUs. Rename it appropriately.
Signed-off-by: Brendan Jackman jackmanb@google.com
tools/testing/selftests/mm/uffd-common.c | 8 ++++---- tools/testing/selftests/mm/uffd-common.h | 2 +- tools/testing/selftests/mm/uffd-stress.c | 28 ++++++++++++++-------------- tools/testing/selftests/mm/uffd-unit-tests.c | 2 +- 4 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index 717539eddf98754250e70e564cd9a59f398bd7ea..a72a2ed5e89480ed06c81b034967ed5ae5f8cad5 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -10,7 +10,7 @@ #define BASE_PMD_ADDR ((void *)(1UL << 30)) volatile bool test_uffdio_copy_eexist = true; -unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; +unsigned long nr_threads, nr_pages, nr_pages_per_cpu, page_size; char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap; int uffd = -1, uffd_flags, finished, *pipefd, test_type; bool map_shared; @@ -269,7 +269,7 @@ void uffd_test_ctx_clear(void) size_t i; if (pipefd) {
for (i = 0; i < nr_cpus * 2; ++i) {
for (i = 0; i < nr_threads * 2; ++i) { if (close(pipefd[i])) err("close pipefd");@@ -365,10 +365,10 @@ int uffd_test_ctx_init(uint64_t features, const char **errmsg) */ uffd_test_ops->release_pages(area_dst);
- pipefd = malloc(sizeof(int) * nr_cpus * 2);
- pipefd = malloc(sizeof(int) * nr_threads * 2); if (!pipefd) err("pipefd");
- for (cpu = 0; cpu < nr_cpus; cpu++)
- for (cpu = 0; cpu < nr_threads; cpu++) if (pipe2(&pipefd[cpu * 2], O_CLOEXEC | O_NONBLOCK)) err("pipe");
diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h index a70ae10b5f6206daecc8e19ed3e3bbb388e265aa..604e3572fe17280ae346b031e2e867e039578f95 100644 --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -98,7 +98,7 @@ struct uffd_test_case_ops { }; typedef struct uffd_test_case_ops uffd_test_case_ops_t; -extern unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; +extern unsigned long nr_threads, nr_pages, nr_pages_per_cpu, page_size; extern char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap; extern int uffd, uffd_flags, finished, *pipefd, test_type; extern bool map_shared; diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c index ed68436fac62c76e2ca7060c661487f2f8a6ab45..ec842bbb9f18e291fa51de0ed8d1fbf9aaf14372 100644 --- a/tools/testing/selftests/mm/uffd-stress.c +++ b/tools/testing/selftests/mm/uffd-stress.c @@ -179,12 +179,12 @@ 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_threads];
- pthread_t uffd_threads[nr_threads];
- pthread_t background_threads[nr_threads];
finished = 0;
- for (cpu = 0; cpu < nr_cpus; cpu++) {
- for (cpu = 0; cpu < nr_threads; cpu++) { if (pthread_create(&locking_threads[cpu], &attr, locking_thread, (void *)cpu)) return 1;
@@ -202,7 +202,7 @@ 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_threads; cpu++) if (pthread_join(background_threads[cpu], NULL)) return 1;
@@ -218,11 +218,11 @@ 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_threads; cpu++) if (pthread_join(locking_threads[cpu], NULL)) return 1;
- for (cpu = 0; cpu < nr_cpus; cpu++) {
- for (cpu = 0; cpu < nr_threads; cpu++) { char c; if (bounces & BOUNCE_POLL) { if (write(pipefd[cpu*2+1], &c, 1) != 1)
@@ -245,11 +245,11 @@ static int userfaultfd_stress(void) { void *area; unsigned long nr;
- struct uffd_args args[nr_cpus];
- struct uffd_args args[nr_threads]; 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_threads);
if (features & UFFD_FEATURE_WP_UNPOPULATED && test_type == TEST_ANON) flags = UFFD_FEATURE_WP_UNPOPULATED; @@ -324,7 +324,7 @@ static int userfaultfd_stress(void) */ uffd_test_ops->release_pages(area_dst);
uffd_stats_reset(args, nr_cpus);
uffd_stats_reset(args, nr_threads);/* bounce pass */ if (stress(args)) { @@ -358,7 +358,7 @@ static int userfaultfd_stress(void) swap(area_src_alias, area_dst_alias);
uffd_stats_report(args, nr_cpus);
uffd_stats_report(args, nr_threads);@@ -452,9 +452,9 @@ int main(int argc, char **argv) return KSFT_SKIP; }
- nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
- nr_threads = sysconf(_SC_NPROCESSORS_ONLN);
- nr_pages_per_cpu = bytes / page_size / nr_cpus;
- nr_pages_per_cpu = bytes / page_size / nr_threads; if (!nr_pages_per_cpu) { _err("invalid MiB"); usage();
@@ -465,7 +465,7 @@ 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_threads;
printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n", nr_pages, nr_pages_per_cpu); diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 9ff71fa1f9bf09b3ae599250663a25bbe2c13b8a..2f84fae5642c6f91b75fbf5f5d59ae64a1c15f92 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -197,7 +197,7 @@ uffd_setup_environment(uffd_test_args_t *args, uffd_test_case_t *test, nr_pages = UFFD_TEST_MEM_SIZE / page_size; /* TODO: remove this global var.. it's so ugly */
- nr_cpus = 1;
- nr_threads = 1;
/* Initialize test arguments */ args->mem_type = mem_type;
Taking a cursory look at the test, it creates three threads for each cpu. The bounding of the variable is fine but that being the reason to rename the variable is not making sense to me.
So this can be debugged more easily.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/uffd-stress.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c index ec842bbb9f18e291fa51de0ed8d1fbf9aaf14372..efe2051c393096e237d942c04a264b6611a6e127 100644 --- a/tools/testing/selftests/mm/uffd-stress.c +++ b/tools/testing/selftests/mm/uffd-stress.c @@ -456,7 +456,8 @@ int main(int argc, char **argv)
nr_pages_per_cpu = bytes / page_size / nr_threads; if (!nr_pages_per_cpu) { - _err("invalid MiB"); + _err("pages_per_cpu = 0, cannot test (%lu / %lu / %lu)", + bytes, page_size, nr_threads); usage(); }
On 28/02/25 10:24 pm, Brendan Jackman wrote:
So this can be debugged more easily.
Signed-off-by: Brendan Jackman jackmanb@google.com
Reviewed-by: Dev Jain dev.jain@arm.com
This calculation divides a fixed parameter by an environment-dependent parameter i.e. the number of CPUs.
The simple way to avoid machine-specific failures here is to just put a cap on the max value of the latter.
Suggested-by: Mateusz Guzik mjguzik@gmail.com Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/uffd-stress.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c index efe2051c393096e237d942c04a264b6611a6e127..5656128590373ed376b3b5d9259e5ca3867a4099 100644 --- a/tools/testing/selftests/mm/uffd-stress.c +++ b/tools/testing/selftests/mm/uffd-stress.c @@ -434,6 +434,7 @@ static void sigalrm(int sig)
int main(int argc, char **argv) { + unsigned long nr_cpus; size_t bytes;
if (argc < 4) @@ -452,7 +453,15 @@ int main(int argc, char **argv) return KSFT_SKIP; }
- nr_threads = sysconf(_SC_NPROCESSORS_ONLN); + 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_threads = 32; + } else { + nr_cpus = nr_threads; + }
nr_pages_per_cpu = bytes / page_size / nr_threads; if (!nr_pages_per_cpu) {
On 28/02/25 10:24 pm, Brendan Jackman wrote:
This calculation divides a fixed parameter by an environment-dependent parameter i.e. the number of CPUs.
The simple way to avoid machine-specific failures here is to just put a cap on the max value of the latter.
Suggested-by: Mateusz Guzik mjguzik@gmail.com Signed-off-by: Brendan Jackman jackmanb@google.com
Reviewed-by: Dev Jain dev.jain@arm.com
It seems that 9pfs does not allow truncating unlinked files, Mark Brown has noted that NFS may also behave this way.
It doesn't seem quite right to call this a "bug" but it's probably a special enough case that it makes sense for the test to just SKIP if it happens.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/map_populate.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/tools/testing/selftests/mm/map_populate.c b/tools/testing/selftests/mm/map_populate.c index 5c8a53869b1bd287b09a250edf628a66c25c2439..433e54fb634f793f2eb4c53ba6b791045c9f4986 100644 --- a/tools/testing/selftests/mm/map_populate.c +++ b/tools/testing/selftests/mm/map_populate.c @@ -87,6 +87,13 @@ int main(int argc, char **argv) BUG_ON(!ftmp, "tmpfile()");
ret = ftruncate(fileno(ftmp), MMAP_SZ); + if (ret < 0 && errno == ENOENT) { + /* + * This probably means tmpfile() made a file on a filesystem + * that doesn't handle temporary files the way we want. + */ + ksft_exit_skip("ftruncate(fileno(tmpfile())) gave ENOENT, weird filesystem?\n"); + } BUG_ON(ret, "ftruncate()");
smap = mmap(0, MMAP_SZ, PROT_READ | PROT_WRITE,
Some filesystems don't support funtract()ing unlinked files. They return ENOENT. In that case, skip the test.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/gup_longterm.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/gup_longterm.c b/tools/testing/selftests/mm/gup_longterm.c index 879e9e4e8cce8127656fabe098abf7db5f6c5e23..494ec4102111b9c96fb4947b29c184735ceb8e1c 100644 --- a/tools/testing/selftests/mm/gup_longterm.c +++ b/tools/testing/selftests/mm/gup_longterm.c @@ -96,7 +96,15 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared) int ret;
if (ftruncate(fd, size)) { - ksft_test_result_fail("ftruncate() failed (%s)\n", strerror(errno)); + if (errno == ENOENT) { + /* + * This can happen if the file has been unlinked and the + * filesystem doesn't support truncating unlinked files. + */ + ksft_test_result_skip("ftruncate() failed with ENOENT\n"); + } else { + ksft_test_result_fail("ftruncate() failed (%s)\n", strerror(errno)); + } return; }
This script must be run as root anyway (see all the writing to privileged files in /proc etc).
Remove the unnecessary use of sudo to avoid breaking on single-user systems that don't have sudo. This also avoids confusing readers.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/run_vmtests.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index da7e266681031d2772fb0c4139648904a18e0bf9..0f9fe757c3320a6551e39b6d4552fd4874b0bf43 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -386,7 +386,7 @@ CATEGORY="madv_populate" run_test ./madv_populate
if [ -x ./memfd_secret ] then -(echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope 2>&1) | tap_prefix +(echo 0 > /proc/sys/kernel/yama/ptrace_scope 2>&1) | tap_prefix CATEGORY="memfd_secret" run_test ./memfd_secret fi
On 28/02/25 10:24 pm, Brendan Jackman wrote:
This script must be run as root anyway (see all the writing to privileged files in /proc etc).
Remove the unnecessary use of sudo to avoid breaking on single-user systems that don't have sudo. This also avoids confusing readers.
Signed-off-by: Brendan Jackman jackmanb@google.com
Reviewed-by: Dev Jain dev.jain@arm.com
This test allocates a page of every available size and doesn't have any SKIP logic if the allocation fails. So, ensure it's available and skip the test if we can't do so.
Signed-off-by: Brendan Jackman jackmanb@google.com --- tools/testing/selftests/mm/run_vmtests.sh | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 0f9fe757c3320a6551e39b6d4552fd4874b0bf43..e86ef8cb37d00e572be8cf0ea9cc8246d4eecd7e 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -309,9 +309,30 @@ CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb "$half_ufd_size_MB" 3 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb-private "$half_ufd_size_MB" 32 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem 20 16 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem-private 20 16 -CATEGORY="userfaultfd" run_test ./uffd-wp-mremap +# uffd-wp-mremap requires at least one page of each size. +have_all_size_hugepgs=true +declare -A nr_size_hugepgs +for f in /sys/kernel/mm/hugepages/**/nr_hugepages; do + old=$(cat $f) + nr_size_hugepgs["$f"]="$old" + if [ "$old" == 0 ]; then + echo 1 > "$f" + fi + if [ $(cat "$f") == 0 ]; then + have_all_size_hugepgs=false + break + fi +done +if $have_all_size_hugepgs; then + CATEGORY="userfaultfd" run_test ./uffd-wp-mremap +else + echo "# SKIP ./uffd-wp-mremap" +fi
#cleanup +for f in "${!nr_size_hugepgs[@]}"; do + echo "${nr_size_hugepgs["$f"]}" > "$f" +done echo "$nr_hugepgs" > /proc/sys/vm/nr_hugepages
CATEGORY="compaction" run_test ./compaction_test
linux-kselftest-mirror@lists.linaro.org
-
Brendan Jackman -
Dev Jain