Re: [RFC PATCH v3 8/8] mm: test system-wide workingset reporting

Please add selftest tag in the subject in selftest patches.

On 3/28/24 2:31 AM, Yuanchu Xie wrote:

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

Thanks for writing most of the test in TAP compliant format. Only replace printing directly to strerr to ksft_exit_fail_msg() instead.

---

tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 3 + .../testing/selftests/mm/workingset_report.c | 315 +++++++++++++++++ .../testing/selftests/mm/workingset_report.h | 37 ++ .../selftests/mm/workingset_report_test.c | 328 ++++++++++++++++++ 5 files changed, 684 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..93387f0f30ee --- /dev/null +++ b/tools/testing/selftests/mm/workingset_report.c @@ -0,0 +1,315 @@ +// 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>

+#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 *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) {

• fprintf(stderr, "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) {

• fprintf(stderr, "cannot find %s in page_age", interval);
  

• return -1;
  

• }
• found = strstr(found, type[pagetype]);
• if (!found) {

• fprintf(stderr, "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;
  

• perror("failed to open temp file\n");
  

• goto cleanup;
  

• }
• if (fallocate(fd, 0, 0, size) < 0) {

• err = -errno;
  

• perror("fallocate");
  

• goto cleanup;
  

• }
• mapped = (char *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED,

• 	      fd, 0);
  

• if (mapped == NULL) {

• err = -errno;
  

• 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) {

• fprintf(stderr, "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..f72a931298e0 --- /dev/null +++ b/tools/testing/selftests/mm/workingset_report.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef WORKINGSET_REPORT_H_ +#define WORKINGSET_REPORT_H_

+#define _GNU_SOURCE

+#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 *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..e6e857d8fe35 --- /dev/null +++ b/tools/testing/selftests/mm/workingset_report_test.c @@ -0,0 +1,328 @@ +// 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 abs(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)) +/* add one for the catch all last interval */

+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) {

• fprintf(stderr, "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)) {
  

• fprintf(stderr, "failed to allocate memory for intervals\n");
  

• return KSFT_FAIL;
  

• }
• err = get_refresh_interval_all_nodes(old_refresh_intervals, nr_nodes);
• if (err < 0) {

• fprintf(stderr, "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) {

• fprintf(stderr, "failed to read page age interval\n");
  

• return KSFT_FAIL;
  

• }
• for (i = 0; i < nr_nodes; ++i)

• new_refresh_intervals[i] = REFRESH_INTERVAL;
  

• err = set_refresh_interval_all_nodes(new_refresh_intervals, nr_nodes);
• if (err < 0) {

• fprintf(stderr, "failed to set refresh interval\n");
  

• test_result = KSFT_FAIL;
  

• goto fail;
  

• }
• 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) {
  

• 	fprintf(stderr, "failed to set page age 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) {

• fprintf(stderr, "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) {

• fprintf(stderr, "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);
  

• if (!values_close(ws_size_test - ws_size_ref, TEST_SIZE, 10)) {
  

• 	fprintf(stderr,
  

• 		"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);
  

• if (ws_size_test < 0)
  

• 	goto cleanup;
  

• if (!values_close(ws_size_test - ws_size_ref, TEST_SIZE, 10)) {
  

• 	fprintf(stderr,
  

• 		"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;

+}