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@xxxxxxxxxx>
---
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;
+}
--
2.45.0.rc1.225.g2a3ae87e7f-goog
