From 800ddf3cd74bda8061105cab7cc169b9a2667f44 Mon Sep 17 00:00:00 2001 From: Brendan Jackman Date: Tue, 11 Mar 2025 13:18:12 +0000 Subject: [PATCH] selftests/mm: report errno when things fail in gup_longterm Patch series "selftests/mm: Some cleanups from trying to run them", v4. 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 - mlock I've never gone past "Waiting for hugetlb memory to get depleted", in the hugetlb tests. I don't know if they are stuck or if they would eventually work if I was patient enough (testing on a 1G machine). I have not investigated further. I had some issues with mlock tests failing due to -ENOSRCH from mlock2(), I can no longer reproduce that though, things work OK now. Of the remaining tests there may be others that work fine, but there's no convenient way to survey the whole output of run_vmtests.sh so I'm just going test by test here. In my spare moments I am slowly chipping away at a setup to run these tests continuously in a reasonably hermetic QEMU environment via virtme-ng: https://github.com/bjackman/linux/blob/5fad4b9c592290f38e0f8bc73c9abb9c99d8787c/README.md Hopefully that will eventually offer a way to provide a "canned" environment where the tests are known to work, which can be fairly easily reproduced by any developer. This patch (of 12): 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. Link: https://lkml.kernel.org/r/20250311-mm-selftests-v4-0-dec210a658f5@google.com Link: https://lkml.kernel.org/r/20250311-mm-selftests-v4-1-dec210a658f5@google.com Signed-off-by: Brendan Jackman Reviewed-by: Dev Jain Cc: Lorenzo Stoakes Cc: Mateusz Guzik Cc: Shuah Khan Signed-off-by: Andrew Morton --- 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 9423ad439a61..15335820656b 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(-ret)); 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(-ret)); } 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; } -- 2.50.1