Add test cases to test the correctness of PFN ZERO flag of pagemap_scan ioctl. Test with normal pages backed memory and huge pages backed memory.
Cc: David Hildenbrand <[email protected]> Signed-off-by: Muhammad Usama Anjum <[email protected]> --- The bug has been fixed [1]. [1] https://lore.kernel.org/all/[email protected] Changes since v1: - Skip if madvise() fails - Skip test if use_zero_page isn't set to 1 - Keep on using memalign()+free() to allocate huge pages Changes sice v2: - Move zero page detection code out to vm_util and use that - Use mmap instead of memalign to allocate hugepage --- tools/testing/selftests/mm/cow.c | 27 +------- tools/testing/selftests/mm/pagemap_ioctl.c | 72 +++++++++++++++++++++- tools/testing/selftests/mm/vm_util.c | 23 +++++++ tools/testing/selftests/mm/vm_util.h | 2 + 4 files changed, 95 insertions(+), 29 deletions(-) diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c index b6cfe0a4b7dfd..b26bbf6ec4617 100644 --- a/tools/testing/selftests/mm/cow.c +++ b/tools/testing/selftests/mm/cow.c @@ -72,31 +72,6 @@ static int detect_thp_sizes(size_t sizes[], int max) return count; } -static void detect_huge_zeropage(void) -{ - int fd = open("/sys/kernel/mm/transparent_hugepage/use_zero_page", - O_RDONLY); - size_t enabled = 0; - char buf[15]; - int ret; - - if (fd < 0) - return; - - ret = pread(fd, buf, sizeof(buf), 0); - if (ret > 0 && ret < sizeof(buf)) { - buf[ret] = 0; - - enabled = strtoul(buf, NULL, 10); - if (enabled == 1) { - has_huge_zeropage = true; - ksft_print_msg("[INFO] huge zeropage is enabled\n"); - } - } - - close(fd); -} - static bool range_is_swapped(void *addr, size_t size) { for (; size; addr += pagesize, size -= pagesize) @@ -1791,7 +1766,7 @@ int main(int argc, char **argv) } nr_hugetlbsizes = detect_hugetlb_page_sizes(hugetlbsizes, ARRAY_SIZE(hugetlbsizes)); - detect_huge_zeropage(); + has_huge_zeropage = detect_huge_zeropage(); ksft_set_plan(ARRAY_SIZE(anon_test_cases) * tests_per_anon_test_case() + ARRAY_SIZE(anon_thp_test_cases) * tests_per_anon_thp_test_case() + diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c b/tools/testing/selftests/mm/pagemap_ioctl.c index 57b4bba2b45f3..059c6d5f971e7 100644 --- a/tools/testing/selftests/mm/pagemap_ioctl.c +++ b/tools/testing/selftests/mm/pagemap_ioctl.c @@ -1,4 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 + #define _GNU_SOURCE #include <stdio.h> #include <fcntl.h> @@ -34,8 +35,8 @@ #define PAGEMAP "/proc/self/pagemap" int pagemap_fd; int uffd; -unsigned int page_size; -unsigned int hpage_size; +size_t page_size; +size_t hpage_size; const char *progname; #define LEN(region) ((region.end - region.start)/page_size) @@ -1480,6 +1481,68 @@ static void transact_test(int page_size) extra_thread_faults); } +void zeropfn_tests(void) +{ + unsigned long long mem_size; + struct page_region vec; + int i, ret; + char *mmap_mem, *mem; + + /* Test with normal memory */ + mem_size = 10 * page_size; + mem = mmap(NULL, mem_size, PROT_READ, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + + /* Touch each page to ensure it's mapped */ + for (i = 0; i < mem_size; i += page_size) + (void)((volatile char *)mem)[i]; + + ret = pagemap_ioctl(mem, mem_size, &vec, 1, 0, + (mem_size / page_size), PAGE_IS_PFNZERO, 0, 0, PAGE_IS_PFNZERO); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && LEN(vec) == (mem_size / page_size), + "%s all pages must have PFNZERO set\n", __func__); + + munmap(mem, mem_size); + + /* Test with huge page if user_zero_page is set to 1 */ + if (!detect_huge_zeropage()) { + ksft_test_result_skip("%s use_zero_page not supported or set to 1\n", __func__); + return; + } + + mem_size = 2 * hpage_size; + mmap_mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (mmap_mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + + /* We need a THP-aligned memory area. */ + mem = (char *)(((uintptr_t)mmap_mem + hpage_size) & ~(hpage_size - 1)); + + ret = madvise(mem, hpage_size, MADV_HUGEPAGE); + if (!ret) { + char tmp = *mem; + + asm volatile("" : "+r" (tmp)); + + ret = pagemap_ioctl(mem, hpage_size, &vec, 1, 0, + 0, PAGE_IS_PFNZERO, 0, 0, PAGE_IS_PFNZERO); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && LEN(vec) == (hpage_size / page_size), + "%s all huge pages must have PFNZERO set\n", __func__); + } else { + ksft_test_result_skip("%s huge page not supported\n", __func__); + } + + munmap(mmap_mem, mem_size); +} + int main(int __attribute__((unused)) argc, char *argv[]) { int shmid, buf_size, fd, i, ret; @@ -1494,7 +1557,7 @@ int main(int __attribute__((unused)) argc, char *argv[]) if (init_uffd()) ksft_exit_pass(); - ksft_set_plan(115); + ksft_set_plan(117); page_size = getpagesize(); hpage_size = read_pmd_pagesize(); @@ -1669,6 +1732,9 @@ int main(int __attribute__((unused)) argc, char *argv[]) /* 16. Userfaultfd tests */ userfaultfd_tests(); + /* 17. ZEROPFN tests */ + zeropfn_tests(); + close(pagemap_fd); ksft_exit_pass(); } diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index a36734fb62f38..dde9e8ab4dc46 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -424,3 +424,26 @@ bool check_vmflag_io(void *addr) flags += flaglen; } } + +bool detect_huge_zeropage(void) +{ + int fd = open("/sys/kernel/mm/transparent_hugepage/use_zero_page", + O_RDONLY); + bool enabled = 0; + char buf[15]; + int ret; + + if (fd < 0) + return 0; + + ret = pread(fd, buf, sizeof(buf), 0); + if (ret > 0 && ret < sizeof(buf)) { + buf[ret] = 0; + + if (strtoul(buf, NULL, 10) == 1) + enabled = 1; + } + + close(fd); + return enabled; +} diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 6effafdc4d8a2..ca4c1f78ce18c 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -74,6 +74,8 @@ int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len, unsigned long get_free_hugepages(void); bool check_vmflag_io(void *addr); +bool detect_huge_zeropage(void); + /* * On ppc64 this will only work with radix 2M hugepage size */ -- 2.43.0
