From 7abaacb8e5f55c6adaabc1b6bcbc1915e159fd1d Mon Sep 17 00:00:00 2001 From: Jinjiang Tu Date: Thu, 28 Mar 2024 19:10:09 +0800 Subject: selftest/mm: ksm_functional_tests: refactor mmap_and_merge_range() In order to extend test_prctl_fork() and test_prctl_fork_exec() to make sure that deduplication really happens, mmap_and_merge_range() needs to be refactored. Firstly, mmap_and_merge_range() will be called with no need to call enable KSM by madvise or prctl. So, switch the 'bool use_prctl' parameter to enum ksm_merge_mode. Secondly, mmap_and_merge_range() will be called in child process in the two testcases, it isn't appropriate to call ksft_test_result_{fail, skip}, because the global variables ksft_{fail, skip} aren't consistent with the parent process. Thus, convert calls of ksft_test_result_{fail, skip} to ksft_print_msg(), return differrent error according to the two cases, and rename mmap_and_merge_range() to __mmap_and_merge_range(). For existing callers, introduce new mmap_and_merge_range() to handle different return values of __mmap_and_merge_range(). Link: https://lkml.kernel.org/r/20240328111010.1502191-3-tujinjiang@huawei.com Signed-off-by: Jinjiang Tu Suggested-by: David Hildenbrand Reviewed-by: David Hildenbrand Cc: Johannes Weiner Cc: Kefeng Wang Cc: Nanyong Sun Cc: Rik van Riel Cc: Stefan Roesch Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/ksm_functional_tests.c | 86 ++++++++++++++++------- 1 file changed, 61 insertions(+), 25 deletions(-) diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c index d615767e396b..5462873df84c 100644 --- a/tools/testing/selftests/mm/ksm_functional_tests.c +++ b/tools/testing/selftests/mm/ksm_functional_tests.c @@ -28,6 +28,15 @@ #define MiB (1024 * KiB) #define FORK_EXEC_CHILD_PRG_NAME "ksm_fork_exec_child" +#define MAP_MERGE_FAIL ((void *)-1) +#define MAP_MERGE_SKIP ((void *)-2) + +enum ksm_merge_mode { + KSM_MERGE_PRCTL, + KSM_MERGE_MADVISE, + KSM_MERGE_NONE, /* PRCTL already set */ +}; + static int mem_fd; static int ksm_fd; static int ksm_full_scans_fd; @@ -146,33 +155,34 @@ static int ksm_unmerge(void) return 0; } -static char *mmap_and_merge_range(char val, unsigned long size, int prot, - bool use_prctl) +static char *__mmap_and_merge_range(char val, unsigned long size, int prot, + enum ksm_merge_mode mode) { char *map; + char *err_map = MAP_MERGE_FAIL; int ret; /* Stabilize accounting by disabling KSM completely. */ if (ksm_unmerge()) { - ksft_test_result_fail("Disabling (unmerging) KSM failed\n"); - return MAP_FAILED; + ksft_print_msg("Disabling (unmerging) KSM failed\n"); + return err_map; } if (get_my_merging_pages() > 0) { - ksft_test_result_fail("Still pages merged\n"); - return MAP_FAILED; + ksft_print_msg("Still pages merged\n"); + return err_map; } map = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0); if (map == MAP_FAILED) { - ksft_test_result_fail("mmap() failed\n"); - return MAP_FAILED; + ksft_print_msg("mmap() failed\n"); + return err_map; } /* Don't use THP. Ignore if THP are not around on a kernel. */ if (madvise(map, size, MADV_NOHUGEPAGE) && errno != EINVAL) { - ksft_test_result_fail("MADV_NOHUGEPAGE failed\n"); + ksft_print_msg("MADV_NOHUGEPAGE failed\n"); goto unmap; } @@ -180,27 +190,36 @@ static char *mmap_and_merge_range(char val, unsigned long size, int prot, memset(map, val, size); if (mprotect(map, size, prot)) { - ksft_test_result_skip("mprotect() failed\n"); + ksft_print_msg("mprotect() failed\n"); + err_map = MAP_MERGE_SKIP; goto unmap; } - if (use_prctl) { + switch (mode) { + case KSM_MERGE_PRCTL: ret = prctl(PR_SET_MEMORY_MERGE, 1, 0, 0, 0); if (ret < 0 && errno == EINVAL) { - ksft_test_result_skip("PR_SET_MEMORY_MERGE not supported\n"); + ksft_print_msg("PR_SET_MEMORY_MERGE not supported\n"); + err_map = MAP_MERGE_SKIP; goto unmap; } else if (ret) { - ksft_test_result_fail("PR_SET_MEMORY_MERGE=1 failed\n"); + ksft_print_msg("PR_SET_MEMORY_MERGE=1 failed\n"); goto unmap; } - } else if (madvise(map, size, MADV_MERGEABLE)) { - ksft_test_result_fail("MADV_MERGEABLE failed\n"); - goto unmap; + break; + case KSM_MERGE_MADVISE: + if (madvise(map, size, MADV_MERGEABLE)) { + ksft_print_msg("MADV_MERGEABLE failed\n"); + goto unmap; + } + break; + case KSM_MERGE_NONE: + break; } /* Run KSM to trigger merging and wait. */ if (ksm_merge()) { - ksft_test_result_fail("Running KSM failed\n"); + ksft_print_msg("Running KSM failed\n"); goto unmap; } @@ -209,14 +228,31 @@ static char *mmap_and_merge_range(char val, unsigned long size, int prot, * accounted differently (depending on kernel support). */ if (val && !get_my_merging_pages()) { - ksft_test_result_fail("No pages got merged\n"); + ksft_print_msg("No pages got merged\n"); goto unmap; } return map; unmap: munmap(map, size); - return MAP_FAILED; + return err_map; +} + +static char *mmap_and_merge_range(char val, unsigned long size, int prot, + enum ksm_merge_mode mode) +{ + char *map; + char *ret = MAP_FAILED; + + map = __mmap_and_merge_range(val, size, prot, mode); + if (map == MAP_MERGE_FAIL) + ksft_test_result_fail("Merging memory failed"); + else if (map == MAP_MERGE_SKIP) + ksft_test_result_skip("Merging memory skipped"); + else + ret = map; + + return ret; } static void test_unmerge(void) @@ -226,7 +262,7 @@ static void test_unmerge(void) ksft_print_msg("[RUN] %s\n", __func__); - map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false); + map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE); if (map == MAP_FAILED) return; @@ -264,7 +300,7 @@ static void test_unmerge_zero_pages(void) } /* Let KSM deduplicate zero pages. */ - map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, false); + map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE); if (map == MAP_FAILED) return; @@ -312,7 +348,7 @@ static void test_unmerge_discarded(void) ksft_print_msg("[RUN] %s\n", __func__); - map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false); + map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE); if (map == MAP_FAILED) return; @@ -344,7 +380,7 @@ static void test_unmerge_uffd_wp(void) ksft_print_msg("[RUN] %s\n", __func__); - map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false); + map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE); if (map == MAP_FAILED) return; @@ -545,7 +581,7 @@ static void test_prctl_unmerge(void) ksft_print_msg("[RUN] %s\n", __func__); - map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, true); + map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_PRCTL); if (map == MAP_FAILED) return; @@ -568,7 +604,7 @@ static void test_prot_none(void) ksft_print_msg("[RUN] %s\n", __func__); - map = mmap_and_merge_range(0x11, size, PROT_NONE, false); + map = mmap_and_merge_range(0x11, size, PROT_NONE, KSM_MERGE_MADVISE); if (map == MAP_FAILED) goto unmap; -- cgit v1.2.3