There are some general ksm operations could be used by other related test cases. Put them into vm_util for common use.
This is a preparation patch for later use.
Signed-off-by: Wei Yang richard.weiyang@gmail.com Suggested-by: David Hildenbrand david@redhat.com Cc: David Hildenbrand david@redhat.com Cc: Lorenzo Stoakes lorenzo.stoakes@oracle.com Cc: Rik van Riel riel@surriel.com Cc: Liam R. Howlett Liam.Howlett@oracle.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Harry Yoo harry.yoo@oracle.com
--- v4: * rebase on mm-new(dd1510cefdfe) v3: * rebase on latest mm-unstable v2: * do check on file opening in init_global_file_handlers() * factor out ksm_merge() and ksm_unmerge() instead of partial of it * align the return value of helpers: 0 on success, -errno on error v1: open/close fd in function itself instead of pass as parameter --- .../selftests/mm/ksm_functional_tests.c | 142 +++--------------- tools/testing/selftests/mm/vm_util.c | 123 +++++++++++++++ tools/testing/selftests/mm/vm_util.h | 7 + 3 files changed, 154 insertions(+), 118 deletions(-)
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c index 534aa405cac7..712f43c87736 100644 --- a/tools/testing/selftests/mm/ksm_functional_tests.c +++ b/tools/testing/selftests/mm/ksm_functional_tests.c @@ -38,11 +38,6 @@ enum ksm_merge_mode { };
static int mem_fd; -static int ksm_fd; -static int ksm_full_scans_fd; -static int proc_self_ksm_stat_fd; -static int proc_self_ksm_merging_pages_fd; -static int ksm_use_zero_pages_fd; static int pagemap_fd; static size_t pagesize;
@@ -75,88 +70,6 @@ static bool range_maps_duplicates(char *addr, unsigned long size) return false; }
-static long get_my_ksm_zero_pages(void) -{ - char buf[200]; - char *substr_ksm_zero; - size_t value_pos; - ssize_t read_size; - unsigned long my_ksm_zero_pages; - - if (!proc_self_ksm_stat_fd) - return 0; - - read_size = pread(proc_self_ksm_stat_fd, buf, sizeof(buf) - 1, 0); - if (read_size < 0) - return -errno; - - buf[read_size] = 0; - - substr_ksm_zero = strstr(buf, "ksm_zero_pages"); - if (!substr_ksm_zero) - return 0; - - value_pos = strcspn(substr_ksm_zero, "0123456789"); - my_ksm_zero_pages = strtol(substr_ksm_zero + value_pos, NULL, 10); - - return my_ksm_zero_pages; -} - -static long get_my_merging_pages(void) -{ - char buf[10]; - ssize_t ret; - - if (proc_self_ksm_merging_pages_fd < 0) - return proc_self_ksm_merging_pages_fd; - - ret = pread(proc_self_ksm_merging_pages_fd, buf, sizeof(buf) - 1, 0); - if (ret <= 0) - return -errno; - buf[ret] = 0; - - return strtol(buf, NULL, 10); -} - -static long ksm_get_full_scans(void) -{ - char buf[10]; - ssize_t ret; - - ret = pread(ksm_full_scans_fd, buf, sizeof(buf) - 1, 0); - if (ret <= 0) - return -errno; - buf[ret] = 0; - - return strtol(buf, NULL, 10); -} - -static int ksm_merge(void) -{ - long start_scans, end_scans; - - /* Wait for two full scans such that any possible merging happened. */ - start_scans = ksm_get_full_scans(); - if (start_scans < 0) - return start_scans; - if (write(ksm_fd, "1", 1) != 1) - return -errno; - do { - end_scans = ksm_get_full_scans(); - if (end_scans < 0) - return end_scans; - } while (end_scans < start_scans + 2); - - return 0; -} - -static int ksm_unmerge(void) -{ - if (write(ksm_fd, "2", 1) != 1) - return -errno; - return 0; -} - static char *__mmap_and_merge_range(char val, unsigned long size, int prot, enum ksm_merge_mode mode) { @@ -165,12 +78,12 @@ static char *__mmap_and_merge_range(char val, unsigned long size, int prot, int ret;
/* Stabilize accounting by disabling KSM completely. */ - if (ksm_unmerge()) { + if (ksm_stop() < 0) { ksft_print_msg("Disabling (unmerging) KSM failed\n"); return err_map; }
- if (get_my_merging_pages() > 0) { + if (ksm_get_self_merging_pages() > 0) { ksft_print_msg("Still pages merged\n"); return err_map; } @@ -220,7 +133,7 @@ static char *__mmap_and_merge_range(char val, unsigned long size, int prot, }
/* Run KSM to trigger merging and wait. */ - if (ksm_merge()) { + if (ksm_start() < 0) { ksft_print_msg("Running KSM failed\n"); goto unmap; } @@ -229,7 +142,7 @@ static char *__mmap_and_merge_range(char val, unsigned long size, int prot, * Check if anything was merged at all. Ignore the zero page that is * accounted differently (depending on kernel support). */ - if (val && !get_my_merging_pages()) { + if (val && !ksm_get_self_merging_pages()) { ksft_print_msg("No pages got merged\n"); goto unmap; } @@ -276,7 +189,7 @@ static void test_unmerge(void) ksft_test_result(!range_maps_duplicates(map, size), "Pages were unmerged\n"); unmap: - ksm_unmerge(); + ksm_stop(); munmap(map, size); }
@@ -289,15 +202,12 @@ static void test_unmerge_zero_pages(void)
ksft_print_msg("[RUN] %s\n", __func__);
- if (proc_self_ksm_stat_fd < 0) { - ksft_test_result_skip("open("/proc/self/ksm_stat") failed\n"); - return; - } - if (ksm_use_zero_pages_fd < 0) { - ksft_test_result_skip("open "/sys/kernel/mm/ksm/use_zero_pages" failed\n"); + if (ksm_get_self_zero_pages() < 0) { + ksft_test_result_skip("accessing "/proc/self/ksm_stat" failed\n"); return; } - if (write(ksm_use_zero_pages_fd, "1", 1) != 1) { + + if (ksm_use_zero_pages() < 0) { ksft_test_result_skip("write "/sys/kernel/mm/ksm/use_zero_pages" failed\n"); return; } @@ -309,7 +219,7 @@ static void test_unmerge_zero_pages(void)
/* Check if ksm_zero_pages is updated correctly after KSM merging */ pages_expected = size / pagesize; - if (pages_expected != get_my_ksm_zero_pages()) { + if (pages_expected != ksm_get_self_zero_pages()) { ksft_test_result_fail("'ksm_zero_pages' updated after merging\n"); goto unmap; } @@ -322,7 +232,7 @@ static void test_unmerge_zero_pages(void)
/* Check if ksm_zero_pages is updated correctly after unmerging */ pages_expected /= 2; - if (pages_expected != get_my_ksm_zero_pages()) { + if (pages_expected != ksm_get_self_zero_pages()) { ksft_test_result_fail("'ksm_zero_pages' updated after unmerging\n"); goto unmap; } @@ -332,7 +242,7 @@ static void test_unmerge_zero_pages(void) *((unsigned int *)&map[offs]) = offs;
/* Now we should have no zeropages remaining. */ - if (get_my_ksm_zero_pages()) { + if (ksm_get_self_zero_pages()) { ksft_test_result_fail("'ksm_zero_pages' updated after write fault\n"); goto unmap; } @@ -341,7 +251,7 @@ static void test_unmerge_zero_pages(void) ksft_test_result(!range_maps_duplicates(map, size), "KSM zero pages were unmerged\n"); unmap: - ksm_unmerge(); + ksm_stop(); munmap(map, size); }
@@ -370,7 +280,7 @@ static void test_unmerge_discarded(void) ksft_test_result(!range_maps_duplicates(map, size), "Pages were unmerged\n"); unmap: - ksm_unmerge(); + ksm_stop(); munmap(map, size); }
@@ -457,7 +367,7 @@ static void test_unmerge_uffd_wp(void) close_uffd: close(uffd); unmap: - ksm_unmerge(); + ksm_stop(); munmap(map, size); } #endif @@ -521,7 +431,7 @@ static int test_child_ksm(void) else if (map == MAP_MERGE_SKIP) return 3;
- ksm_unmerge(); + ksm_stop(); munmap(map, size); return 0; } @@ -654,7 +564,7 @@ static void test_prctl_unmerge(void) ksft_test_result(!range_maps_duplicates(map, size), "Pages were unmerged\n"); unmap: - ksm_unmerge(); + ksm_stop(); munmap(map, size); }
@@ -688,7 +598,7 @@ static void test_prot_none(void) ksft_test_result(!range_maps_duplicates(map, size), "Pages were unmerged\n"); unmap: - ksm_unmerge(); + ksm_stop(); munmap(map, size); }
@@ -697,19 +607,15 @@ static void init_global_file_handles(void) mem_fd = open("/proc/self/mem", O_RDWR); if (mem_fd < 0) ksft_exit_fail_msg("opening /proc/self/mem failed\n"); - ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR); - if (ksm_fd < 0) - ksft_exit_skip("open("/sys/kernel/mm/ksm/run") failed\n"); - ksm_full_scans_fd = open("/sys/kernel/mm/ksm/full_scans", O_RDONLY); - if (ksm_full_scans_fd < 0) - ksft_exit_skip("open("/sys/kernel/mm/ksm/full_scans") failed\n"); + if (ksm_stop() < 0) + ksft_exit_skip("accessing "/sys/kernel/mm/ksm/run") failed\n"); + if (ksm_get_full_scans() < 0) + ksft_exit_skip("accessing "/sys/kernel/mm/ksm/full_scans") failed\n"); pagemap_fd = open("/proc/self/pagemap", O_RDONLY); if (pagemap_fd < 0) ksft_exit_skip("open("/proc/self/pagemap") failed\n"); - proc_self_ksm_stat_fd = open("/proc/self/ksm_stat", O_RDONLY); - proc_self_ksm_merging_pages_fd = open("/proc/self/ksm_merging_pages", - O_RDONLY); - ksm_use_zero_pages_fd = open("/sys/kernel/mm/ksm/use_zero_pages", O_RDWR); + if (ksm_get_self_merging_pages() < 0) + ksft_exit_skip("accessing "/proc/self/ksm_merging_pages") failed\n"); }
int main(int argc, char **argv) diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index 6a239aa413e2..ab7271ed5ff3 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -565,3 +565,126 @@ bool detect_huge_zeropage(void) close(fd); return enabled; } + +long ksm_get_self_zero_pages(void) +{ + int proc_self_ksm_stat_fd; + char buf[200]; + char *substr_ksm_zero; + size_t value_pos; + ssize_t read_size; + + proc_self_ksm_stat_fd = open("/proc/self/ksm_stat", O_RDONLY); + if (proc_self_ksm_stat_fd < 0) + return -errno; + + read_size = pread(proc_self_ksm_stat_fd, buf, sizeof(buf) - 1, 0); + close(proc_self_ksm_stat_fd); + if (read_size < 0) + return -errno; + + buf[read_size] = 0; + + substr_ksm_zero = strstr(buf, "ksm_zero_pages"); + if (!substr_ksm_zero) + return 0; + + value_pos = strcspn(substr_ksm_zero, "0123456789"); + return strtol(substr_ksm_zero + value_pos, NULL, 10); +} + +long ksm_get_self_merging_pages(void) +{ + int proc_self_ksm_merging_pages_fd; + char buf[10]; + ssize_t ret; + + proc_self_ksm_merging_pages_fd = open("/proc/self/ksm_merging_pages", + O_RDONLY); + if (proc_self_ksm_merging_pages_fd < 0) + return -errno; + + ret = pread(proc_self_ksm_merging_pages_fd, buf, sizeof(buf) - 1, 0); + close(proc_self_ksm_merging_pages_fd); + if (ret <= 0) + return -errno; + buf[ret] = 0; + + return strtol(buf, NULL, 10); +} + +long ksm_get_full_scans(void) +{ + int ksm_full_scans_fd; + char buf[10]; + ssize_t ret; + + ksm_full_scans_fd = open("/sys/kernel/mm/ksm/full_scans", O_RDONLY); + if (ksm_full_scans_fd < 0) + return -errno; + + ret = pread(ksm_full_scans_fd, buf, sizeof(buf) - 1, 0); + close(ksm_full_scans_fd); + if (ret <= 0) + return -errno; + buf[ret] = 0; + + return strtol(buf, NULL, 10); +} + +int ksm_use_zero_pages(void) +{ + int ksm_use_zero_pages_fd; + ssize_t ret; + + ksm_use_zero_pages_fd = open("/sys/kernel/mm/ksm/use_zero_pages", O_RDWR); + if (ksm_use_zero_pages_fd < 0) + return -errno; + + ret = write(ksm_use_zero_pages_fd, "1", 1); + close(ksm_use_zero_pages_fd); + return ret == 1 ? 0 : -errno; +} + +int ksm_start(void) +{ + int ksm_fd; + ssize_t ret; + long start_scans, end_scans; + + ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR); + if (ksm_fd < 0) + return -errno; + + /* Wait for two full scans such that any possible merging happened. */ + start_scans = ksm_get_full_scans(); + if (start_scans < 0) { + close(ksm_fd); + return start_scans; + } + ret = write(ksm_fd, "1", 1); + close(ksm_fd); + if (ret != 1) + return -errno; + do { + end_scans = ksm_get_full_scans(); + if (end_scans < 0) + return end_scans; + } while (end_scans < start_scans + 2); + + return 0; +} + +int ksm_stop(void) +{ + int ksm_fd; + ssize_t ret; + + ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR); + if (ksm_fd < 0) + return -errno; + + ret = write(ksm_fd, "2", 1); + close(ksm_fd); + return ret == 1 ? 0 : -errno; +} diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 3da56feeb944..1f9a90668758 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -135,6 +135,13 @@ static inline int sz2ord(size_t size, size_t pagesize) void *sys_mremap(void *old_address, unsigned long old_size, unsigned long new_size, int flags, void *new_address);
+long ksm_get_self_zero_pages(void); +long ksm_get_self_merging_pages(void); +long ksm_get_full_scans(void); +int ksm_use_zero_pages(void); +int ksm_start(void); +int ksm_stop(void); + /* * On ppc64 this will only work with radix 2M hugepage size */