A basic test that verifies the working set size of a simple memory accessor. It should work with or without the aging thread.
Question: I don't know how to best test file memory in selftests. Is there a place where I should put the temporary file? /tmp can be tmpfs mounted in many distros.
Signed-off-by: Yuanchu Xie yuanchu@google.com --- tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 3 + .../testing/selftests/mm/workingset_report.c | 317 +++++++++++++++++ .../testing/selftests/mm/workingset_report.h | 39 ++ .../selftests/mm/workingset_report_test.c | 332 ++++++++++++++++++ 5 files changed, 692 insertions(+) create mode 100644 tools/testing/selftests/mm/workingset_report.c create mode 100644 tools/testing/selftests/mm/workingset_report.h create mode 100644 tools/testing/selftests/mm/workingset_report_test.c
diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore index 4ff10ea61461..14a2412c8257 100644 --- a/tools/testing/selftests/mm/.gitignore +++ b/tools/testing/selftests/mm/.gitignore @@ -46,3 +46,4 @@ gup_longterm mkdirty va_high_addr_switch hugetlb_fault_after_madv +workingset_report_test diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index 2453add65d12..c0869bf07e99 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -70,6 +70,7 @@ TEST_GEN_FILES += ksm_tests TEST_GEN_FILES += ksm_functional_tests TEST_GEN_FILES += mdwe_test TEST_GEN_FILES += hugetlb_fault_after_madv +TEST_GEN_FILES += workingset_report_test
ifneq ($(ARCH),arm64) TEST_GEN_FILES += soft-dirty @@ -123,6 +124,8 @@ $(TEST_GEN_FILES): vm_util.c thp_settings.c $(OUTPUT)/uffd-stress: uffd-common.c $(OUTPUT)/uffd-unit-tests: uffd-common.c
+$(OUTPUT)/workingset_report_test: workingset_report.c + ifeq ($(ARCH),x86_64) BINARIES_32 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_32)) BINARIES_64 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_64)) diff --git a/tools/testing/selftests/mm/workingset_report.c b/tools/testing/selftests/mm/workingset_report.c new file mode 100644 index 000000000000..0d744bae5432 --- /dev/null +++ b/tools/testing/selftests/mm/workingset_report.c @@ -0,0 +1,317 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "workingset_report.h" + +#include <stddef.h> +#include <stdlib.h> +#include <stdio.h> +#include <stdbool.h> +#include <unistd.h> +#include <string.h> +#include <sys/mman.h> +#include <sys/wait.h> + +#include "../kselftest.h" + +#define SYSFS_NODE_ONLINE "/sys/devices/system/node/online" +#define PROC_DROP_CACHES "/proc/sys/vm/drop_caches" + +/* Returns read len on success, or -errno on failure. */ +static ssize_t read_text(const char *path, char *buf, size_t max_len) +{ + ssize_t len; + int fd, err; + size_t bytes_read = 0; + + if (!max_len) + return -EINVAL; + + fd = open(path, O_RDONLY); + if (fd < 0) + return -errno; + + while (bytes_read < max_len - 1) { + len = read(fd, buf + bytes_read, max_len - 1 - bytes_read); + + if (len <= 0) + break; + bytes_read += len; + } + + buf[bytes_read] = '\0'; + + err = -errno; + close(fd); + return len < 0 ? err : bytes_read; +} + +/* Returns written len on success, or -errno on failure. */ +static ssize_t write_text(const char *path, const char *buf, ssize_t max_len) +{ + int fd, len, err; + size_t bytes_written = 0; + + fd = open(path, O_WRONLY | O_APPEND); + if (fd < 0) + return -errno; + + while (bytes_written < max_len) { + len = write(fd, buf + bytes_written, max_len - bytes_written); + + if (len < 0) + break; + bytes_written += len; + } + + err = -errno; + close(fd); + return len < 0 ? err : bytes_written; +} + +static long read_num(const char *path) +{ + char buf[21]; + + if (read_text(path, buf, sizeof(buf)) <= 0) + return -1; + return (long)strtoul(buf, NULL, 10); +} + +static int write_num(const char *path, unsigned long n) +{ + char buf[21]; + + sprintf(buf, "%lu", n); + if (write_text(path, buf, strlen(buf)) < 0) + return -1; + return 0; +} + +long sysfs_get_refresh_interval(int nid) +{ + char file[128]; + + snprintf( + file, + sizeof(file), + "/sys/devices/system/node/node%d/workingset_report/refresh_interval", + nid); + return read_num(file); +} + +int sysfs_set_refresh_interval(int nid, long interval) +{ + char file[128]; + + snprintf( + file, + sizeof(file), + "/sys/devices/system/node/node%d/workingset_report/refresh_interval", + nid); + return write_num(file, interval); +} + +int sysfs_get_page_age_intervals_str(int nid, char *buf, int len) +{ + char path[128]; + + snprintf( + path, + sizeof(path), + "/sys/devices/system/node/node%d/workingset_report/page_age_intervals", + nid); + return read_text(path, buf, len); + +} + +int sysfs_set_page_age_intervals_str(int nid, const char *buf, int len) +{ + char path[128]; + + snprintf( + path, + sizeof(path), + "/sys/devices/system/node/node%d/workingset_report/page_age_intervals", + nid); + return write_text(path, buf, len); +} + +int sysfs_set_page_age_intervals(int nid, const char *const intervals[], + int nr_intervals) +{ + char file[128]; + char buf[1024]; + int i; + int err, len = 0; + + for (i = 0; i < nr_intervals; ++i) { + err = snprintf(buf + len, sizeof(buf) - len, "%s", intervals[i]); + + if (err < 0) + return err; + len += err; + + if (i < nr_intervals - 1) { + err = snprintf(buf + len, sizeof(buf) - len, ","); + if (err < 0) + return err; + len += err; + } + } + + snprintf( + file, + sizeof(file), + "/sys/devices/system/node/node%d/workingset_report/page_age_intervals", + nid); + return write_text(file, buf, len); +} + +int get_nr_nodes(void) +{ + char buf[22]; + char *found; + + if (read_text(SYSFS_NODE_ONLINE, buf, sizeof(buf)) <= 0) + return -1; + found = strstr(buf, "-"); + if (found) + return (int)strtoul(found + 1, NULL, 10) + 1; + return (long)strtoul(buf, NULL, 10) + 1; +} + +int drop_pagecache(void) +{ + return write_num(PROC_DROP_CACHES, 1); +} + +ssize_t sysfs_page_age_read(int nid, char *buf, size_t len) + +{ + char file[128]; + + snprintf(file, + sizeof(file), + "/sys/devices/system/node/node%d/workingset_report/page_age", + nid); + return read_text(file, buf, len); +} + +/* + * Finds the first occurrence of "N<nid>\n" + * Modifies buf to terminate before the next occurrence of "N". + * Returns a substring of buf starting after "N<nid>\n" + */ +char *page_age_split_node(char *buf, int nid, char **next) +{ + char node_str[5]; + char *found; + int node_str_len; + + node_str_len = snprintf(node_str, sizeof(node_str), "N%u\n", nid); + + /* find the node prefix first */ + found = strstr(buf, node_str); + if (!found) { + ksft_print_msg("cannot find '%s' in page_idle_age", node_str); + return NULL; + } + found += node_str_len; + + *next = strchr(found, 'N'); + if (*next) + *(*next - 1) = '\0'; + + return found; +} + +ssize_t page_age_read(const char *buf, const char *interval, int pagetype) +{ + static const char * const type[ANON_AND_FILE] = { "anon=", "file=" }; + char *found; + + found = strstr(buf, interval); + if (!found) { + ksft_print_msg("cannot find %s in page_age", interval); + return -1; + } + found = strstr(found, type[pagetype]); + if (!found) { + ksft_print_msg("cannot find %s in page_age", type[pagetype]); + return -1; + } + found += strlen(type[pagetype]); + return (long)strtoul(found, NULL, 10); +} + +static const char *TEMP_FILE = "/tmp/workingset_selftest"; +void cleanup_file_workingset(void) +{ + remove(TEMP_FILE); +} + +int alloc_file_workingset(void *arg) +{ + int err = 0; + char *ptr; + int fd; + int ppid; + char *mapped; + size_t size = (size_t)arg; + size_t page_size = getpagesize(); + + ppid = getppid(); + + fd = open(TEMP_FILE, O_RDWR | O_CREAT); + if (fd < 0) { + err = -errno; + ksft_perror("failed to open temp file\n"); + goto cleanup; + } + + if (fallocate(fd, 0, 0, size) < 0) { + err = -errno; + ksft_perror("fallocate"); + goto cleanup; + } + + mapped = (char *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, + fd, 0); + if (mapped == NULL) { + err = -errno; + ksft_perror("mmap"); + goto cleanup; + } + + while (getppid() == ppid) { + sync(); + for (ptr = mapped; ptr < mapped + size; ptr += page_size) + *ptr = *ptr ^ 0xFF; + } + +cleanup: + cleanup_file_workingset(); + return err; +} + +int alloc_anon_workingset(void *arg) +{ + char *buf, *ptr; + int ppid = getppid(); + size_t size = (size_t)arg; + size_t page_size = getpagesize(); + + buf = malloc(size); + + if (!buf) { + ksft_print_msg("cannot allocate anon workingset"); + exit(1); + } + + while (getppid() == ppid) { + for (ptr = buf; ptr < buf + size; ptr += page_size) + *ptr = *ptr ^ 0xFF; + } + + free(buf); + return 0; +} diff --git a/tools/testing/selftests/mm/workingset_report.h b/tools/testing/selftests/mm/workingset_report.h new file mode 100644 index 000000000000..c5c281e4069b --- /dev/null +++ b/tools/testing/selftests/mm/workingset_report.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef WORKINGSET_REPORT_H_ +#define WORKINGSET_REPORT_H_ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include <fcntl.h> +#include <sys/stat.h> +#include <errno.h> +#include <stdint.h> +#include <sys/types.h> + +#define PAGETYPE_ANON 0 +#define PAGETYPE_FILE 1 +#define ANON_AND_FILE 2 + +int get_nr_nodes(void); +int drop_pagecache(void); + +long sysfs_get_refresh_interval(int nid); +int sysfs_set_refresh_interval(int nid, long interval); + +int sysfs_get_page_age_intervals_str(int nid, char *buf, int len); +int sysfs_set_page_age_intervals_str(int nid, const char *buf, int len); + +int sysfs_set_page_age_intervals(int nid, const char *const intervals[], + int nr_intervals); + +char *page_age_split_node(char *buf, int nid, char **next); +ssize_t sysfs_page_age_read(int nid, char *buf, size_t len); +ssize_t page_age_read(const char *buf, const char *interval, int pagetype); + +int alloc_file_workingset(void *arg); +void cleanup_file_workingset(void); +int alloc_anon_workingset(void *arg); + +#endif /* WORKINGSET_REPORT_H_ */ diff --git a/tools/testing/selftests/mm/workingset_report_test.c b/tools/testing/selftests/mm/workingset_report_test.c new file mode 100644 index 000000000000..9a86c2215182 --- /dev/null +++ b/tools/testing/selftests/mm/workingset_report_test.c @@ -0,0 +1,332 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "workingset_report.h" + +#include <stdlib.h> +#include <stdio.h> +#include <signal.h> +#include <time.h> + +#include "../clone3/clone3_selftests.h" + +#define REFRESH_INTERVAL 5000 +#define MB(x) (x << 20) + +static void sleep_ms(int milliseconds) +{ + struct timespec ts; + + ts.tv_sec = milliseconds / 1000; + ts.tv_nsec = (milliseconds % 1000) * 1000000; + nanosleep(&ts, NULL); +} + +/* + * Checks if two given values differ by less than err% of their sum. + */ +static inline int values_close(long a, long b, int err) +{ + return labs(a - b) <= (a + b) / 100 * err; +} + +static const char * const PAGE_AGE_INTERVALS[] = { + "6000", "10000", "15000", "18446744073709551615", +}; +#define NR_PAGE_AGE_INTERVALS (ARRAY_SIZE(PAGE_AGE_INTERVALS)) + +static int set_page_age_intervals_all_nodes(const char *intervals, int nr_nodes) +{ + int i; + + for (i = 0; i < nr_nodes; ++i) { + int err = sysfs_set_page_age_intervals_str( + i, &intervals[i * 1024], strlen(&intervals[i * 1024])); + + if (err < 0) + return err; + } + return 0; +} + +static int get_page_age_intervals_all_nodes(char *intervals, int nr_nodes) +{ + int i; + + for (i = 0; i < nr_nodes; ++i) { + int err = sysfs_get_page_age_intervals_str( + i, &intervals[i * 1024], 1024); + + if (err < 0) + return err; + } + return 0; +} + +static int set_refresh_interval_all_nodes(const long *interval, int nr_nodes) +{ + int i; + + for (i = 0; i < nr_nodes; ++i) { + int err = sysfs_set_refresh_interval(i, interval[i]); + + if (err < 0) + return err; + } + return 0; +} + +static int get_refresh_interval_all_nodes(long *interval, int nr_nodes) +{ + int i; + + for (i = 0; i < nr_nodes; ++i) { + long val = sysfs_get_refresh_interval(i); + + if (val < 0) + return val; + interval[i] = val; + } + return 0; +} + +static pid_t clone_and_run(int fn(void *arg), void *arg) +{ + pid_t pid; + + struct __clone_args args = { + .exit_signal = SIGCHLD, + }; + + pid = sys_clone3(&args, sizeof(struct __clone_args)); + + if (pid == 0) + exit(fn(arg)); + + return pid; +} + +static int read_workingset(int pagetype, int nid, + unsigned long page_age[NR_PAGE_AGE_INTERVALS]) +{ + int i, err; + char buf[4096]; + + err = sysfs_page_age_read(nid, buf, sizeof(buf)); + if (err < 0) + return err; + + for (i = 0; i < NR_PAGE_AGE_INTERVALS; ++i) { + err = page_age_read(buf, PAGE_AGE_INTERVALS[i], pagetype); + if (err < 0) + return err; + page_age[i] = err; + } + + return 0; +} + +static ssize_t read_interval_all_nodes(int pagetype, int interval) +{ + int i, err; + unsigned long page_age[NR_PAGE_AGE_INTERVALS]; + ssize_t ret = 0; + int nr_nodes = get_nr_nodes(); + + for (i = 0; i < nr_nodes; ++i) { + err = read_workingset(pagetype, i, page_age); + if (err < 0) + return err; + + ret += page_age[interval]; + } + + return ret; +} + +#define TEST_SIZE MB(500l) + +static int run_test(int f(void)) +{ + int i, err, test_result; + long *old_refresh_intervals; + long *new_refresh_intervals; + char *old_page_age_intervals; + int nr_nodes = get_nr_nodes(); + + if (nr_nodes <= 0) { + ksft_print_msg("failed to get nr_nodes\n"); + return KSFT_FAIL; + } + + old_refresh_intervals = calloc(nr_nodes, sizeof(long)); + new_refresh_intervals = calloc(nr_nodes, sizeof(long)); + old_page_age_intervals = calloc(nr_nodes, 1024); + + if (!(old_refresh_intervals && new_refresh_intervals && + old_page_age_intervals)) { + ksft_print_msg("failed to allocate memory for intervals\n"); + return KSFT_FAIL; + } + + err = get_refresh_interval_all_nodes(old_refresh_intervals, nr_nodes); + if (err < 0) { + ksft_print_msg("failed to read refresh interval\n"); + return KSFT_FAIL; + } + + err = get_page_age_intervals_all_nodes(old_page_age_intervals, nr_nodes); + if (err < 0) { + ksft_print_msg("failed to read page age interval\n"); + return KSFT_FAIL; + } + + for (i = 0; i < nr_nodes; ++i) + new_refresh_intervals[i] = REFRESH_INTERVAL; + + for (i = 0; i < nr_nodes; ++i) { + err = sysfs_set_page_age_intervals(i, PAGE_AGE_INTERVALS, + NR_PAGE_AGE_INTERVALS - 1); + if (err < 0) { + ksft_print_msg("failed to set page age interval\n"); + test_result = KSFT_FAIL; + goto fail; + } + } + + err = set_refresh_interval_all_nodes(new_refresh_intervals, nr_nodes); + if (err < 0) { + ksft_print_msg("failed to set refresh interval\n"); + test_result = KSFT_FAIL; + goto fail; + } + + sync(); + drop_pagecache(); + + test_result = f(); + +fail: + err = set_refresh_interval_all_nodes(old_refresh_intervals, nr_nodes); + if (err < 0) { + ksft_print_msg("failed to restore refresh interval\n"); + test_result = KSFT_FAIL; + } + err = set_page_age_intervals_all_nodes(old_page_age_intervals, nr_nodes); + if (err < 0) { + ksft_print_msg("failed to restore page age interval\n"); + test_result = KSFT_FAIL; + } + return test_result; +} + +static int test_file(void) +{ + ssize_t ws_size_ref, ws_size_test; + int ret = KSFT_FAIL, i; + pid_t pid = 0; + + ws_size_ref = read_interval_all_nodes(PAGETYPE_FILE, 0); + if (ws_size_ref < 0) + goto cleanup; + + pid = clone_and_run(alloc_file_workingset, (void *)TEST_SIZE); + if (pid < 0) + goto cleanup; + + read_interval_all_nodes(PAGETYPE_FILE, 0); + sleep_ms(REFRESH_INTERVAL); + + for (i = 0; i < 3; ++i) { + sleep_ms(REFRESH_INTERVAL); + ws_size_test = read_interval_all_nodes(PAGETYPE_FILE, 0); + ws_size_test += read_interval_all_nodes(PAGETYPE_FILE, 1); + if (ws_size_test < 0) + goto cleanup; + + if (!values_close(ws_size_test - ws_size_ref, TEST_SIZE, 10)) { + ksft_print_msg( + "file working set size difference too large: actual=%ld, expected=%ld\n", + ws_size_test - ws_size_ref, TEST_SIZE); + goto cleanup; + } + } + ret = KSFT_PASS; + +cleanup: + if (pid > 0) + kill(pid, SIGKILL); + cleanup_file_workingset(); + return ret; +} + +static int test_anon(void) +{ + ssize_t ws_size_ref, ws_size_test; + pid_t pid = 0; + int ret = KSFT_FAIL, i; + + ws_size_ref = read_interval_all_nodes(PAGETYPE_ANON, 0); + if (ws_size_ref < 0) + goto cleanup; + + pid = clone_and_run(alloc_anon_workingset, (void *)TEST_SIZE); + if (pid < 0) + goto cleanup; + + sleep_ms(REFRESH_INTERVAL); + read_interval_all_nodes(PAGETYPE_ANON, 0); + + for (i = 0; i < 5; ++i) { + sleep_ms(REFRESH_INTERVAL); + ws_size_test = read_interval_all_nodes(PAGETYPE_ANON, 0); + ws_size_test += read_interval_all_nodes(PAGETYPE_ANON, 1); + if (ws_size_test < 0) + goto cleanup; + + if (!values_close(ws_size_test - ws_size_ref, TEST_SIZE, 10)) { + ksft_print_msg( + "anon working set size difference too large: actual=%ld, expected=%ld\n", + ws_size_test - ws_size_ref, TEST_SIZE); + goto cleanup; + } + } + ret = KSFT_PASS; + +cleanup: + if (pid > 0) + kill(pid, SIGKILL); + return ret; +} + + +#define T(x) { x, #x } +struct workingset_test { + int (*fn)(void); + const char *name; +} tests[] = { + T(test_anon), + T(test_file), +}; +#undef T + +int main(int argc, char **argv) +{ + int ret = EXIT_SUCCESS, i, err; + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + err = run_test(tests[i].fn); + switch (err) { + case KSFT_PASS: + ksft_test_result_pass("%s\n", tests[i].name); + break; + case KSFT_SKIP: + ksft_test_result_skip("%s\n", tests[i].name); + break; + default: + ret = EXIT_FAILURE; + ksft_test_result_fail("%s with error %d\n", + tests[i].name, err); + break; + } + } + return ret; +}