diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/cgroup/test_cpu.c | 726 |
1 files changed, 726 insertions, 0 deletions
diff --git a/tools/testing/selftests/cgroup/test_cpu.c b/tools/testing/selftests/cgroup/test_cpu.c new file mode 100644 index 000000000..24020a2c6 --- /dev/null +++ b/tools/testing/selftests/cgroup/test_cpu.c @@ -0,0 +1,726 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <linux/limits.h> +#include <sys/sysinfo.h> +#include <sys/wait.h> +#include <errno.h> +#include <pthread.h> +#include <stdio.h> +#include <time.h> + +#include "../kselftest.h" +#include "cgroup_util.h" + +enum hog_clock_type { + // Count elapsed time using the CLOCK_PROCESS_CPUTIME_ID clock. + CPU_HOG_CLOCK_PROCESS, + // Count elapsed time using system wallclock time. + CPU_HOG_CLOCK_WALL, +}; + +struct cpu_hogger { + char *cgroup; + pid_t pid; + long usage; +}; + +struct cpu_hog_func_param { + int nprocs; + struct timespec ts; + enum hog_clock_type clock_type; +}; + +/* + * This test creates two nested cgroups with and without enabling + * the cpu controller. + */ +static int test_cpucg_subtree_control(const char *root) +{ + char *parent = NULL, *child = NULL, *parent2 = NULL, *child2 = NULL; + int ret = KSFT_FAIL; + + // Create two nested cgroups with the cpu controller enabled. + parent = cg_name(root, "cpucg_test_0"); + if (!parent) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+cpu")) + goto cleanup; + + child = cg_name(parent, "cpucg_test_child"); + if (!child) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_read_strstr(child, "cgroup.controllers", "cpu")) + goto cleanup; + + // Create two nested cgroups without enabling the cpu controller. + parent2 = cg_name(root, "cpucg_test_1"); + if (!parent2) + goto cleanup; + + if (cg_create(parent2)) + goto cleanup; + + child2 = cg_name(parent2, "cpucg_test_child"); + if (!child2) + goto cleanup; + + if (cg_create(child2)) + goto cleanup; + + if (!cg_read_strstr(child2, "cgroup.controllers", "cpu")) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_destroy(child); + free(child); + cg_destroy(child2); + free(child2); + cg_destroy(parent); + free(parent); + cg_destroy(parent2); + free(parent2); + + return ret; +} + +static void *hog_cpu_thread_func(void *arg) +{ + while (1) + ; + + return NULL; +} + +static struct timespec +timespec_sub(const struct timespec *lhs, const struct timespec *rhs) +{ + struct timespec zero = { + .tv_sec = 0, + .tv_nsec = 0, + }; + struct timespec ret; + + if (lhs->tv_sec < rhs->tv_sec) + return zero; + + ret.tv_sec = lhs->tv_sec - rhs->tv_sec; + + if (lhs->tv_nsec < rhs->tv_nsec) { + if (ret.tv_sec == 0) + return zero; + + ret.tv_sec--; + ret.tv_nsec = NSEC_PER_SEC - rhs->tv_nsec + lhs->tv_nsec; + } else + ret.tv_nsec = lhs->tv_nsec - rhs->tv_nsec; + + return ret; +} + +static int hog_cpus_timed(const char *cgroup, void *arg) +{ + const struct cpu_hog_func_param *param = + (struct cpu_hog_func_param *)arg; + struct timespec ts_run = param->ts; + struct timespec ts_remaining = ts_run; + struct timespec ts_start; + int i, ret; + + ret = clock_gettime(CLOCK_MONOTONIC, &ts_start); + if (ret != 0) + return ret; + + for (i = 0; i < param->nprocs; i++) { + pthread_t tid; + + ret = pthread_create(&tid, NULL, &hog_cpu_thread_func, NULL); + if (ret != 0) + return ret; + } + + while (ts_remaining.tv_sec > 0 || ts_remaining.tv_nsec > 0) { + struct timespec ts_total; + + ret = nanosleep(&ts_remaining, NULL); + if (ret && errno != EINTR) + return ret; + + if (param->clock_type == CPU_HOG_CLOCK_PROCESS) { + ret = clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts_total); + if (ret != 0) + return ret; + } else { + struct timespec ts_current; + + ret = clock_gettime(CLOCK_MONOTONIC, &ts_current); + if (ret != 0) + return ret; + + ts_total = timespec_sub(&ts_current, &ts_start); + } + + ts_remaining = timespec_sub(&ts_run, &ts_total); + } + + return 0; +} + +/* + * Creates a cpu cgroup, burns a CPU for a few quanta, and verifies that + * cpu.stat shows the expected output. + */ +static int test_cpucg_stats(const char *root) +{ + int ret = KSFT_FAIL; + long usage_usec, user_usec, system_usec; + long usage_seconds = 2; + long expected_usage_usec = usage_seconds * USEC_PER_SEC; + char *cpucg; + + cpucg = cg_name(root, "cpucg_test"); + if (!cpucg) + goto cleanup; + + if (cg_create(cpucg)) + goto cleanup; + + usage_usec = cg_read_key_long(cpucg, "cpu.stat", "usage_usec"); + user_usec = cg_read_key_long(cpucg, "cpu.stat", "user_usec"); + system_usec = cg_read_key_long(cpucg, "cpu.stat", "system_usec"); + if (usage_usec != 0 || user_usec != 0 || system_usec != 0) + goto cleanup; + + struct cpu_hog_func_param param = { + .nprocs = 1, + .ts = { + .tv_sec = usage_seconds, + .tv_nsec = 0, + }, + .clock_type = CPU_HOG_CLOCK_PROCESS, + }; + if (cg_run(cpucg, hog_cpus_timed, (void *)¶m)) + goto cleanup; + + usage_usec = cg_read_key_long(cpucg, "cpu.stat", "usage_usec"); + user_usec = cg_read_key_long(cpucg, "cpu.stat", "user_usec"); + if (user_usec <= 0) + goto cleanup; + + if (!values_close(usage_usec, expected_usage_usec, 1)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_destroy(cpucg); + free(cpucg); + + return ret; +} + +static int +run_cpucg_weight_test( + const char *root, + pid_t (*spawn_child)(const struct cpu_hogger *child), + int (*validate)(const struct cpu_hogger *children, int num_children)) +{ + int ret = KSFT_FAIL, i; + char *parent = NULL; + struct cpu_hogger children[3] = {NULL}; + + parent = cg_name(root, "cpucg_test_0"); + if (!parent) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+cpu")) + goto cleanup; + + for (i = 0; i < ARRAY_SIZE(children); i++) { + children[i].cgroup = cg_name_indexed(parent, "cpucg_child", i); + if (!children[i].cgroup) + goto cleanup; + + if (cg_create(children[i].cgroup)) + goto cleanup; + + if (cg_write_numeric(children[i].cgroup, "cpu.weight", + 50 * (i + 1))) + goto cleanup; + } + + for (i = 0; i < ARRAY_SIZE(children); i++) { + pid_t pid = spawn_child(&children[i]); + if (pid <= 0) + goto cleanup; + children[i].pid = pid; + } + + for (i = 0; i < ARRAY_SIZE(children); i++) { + int retcode; + + waitpid(children[i].pid, &retcode, 0); + if (!WIFEXITED(retcode)) + goto cleanup; + if (WEXITSTATUS(retcode)) + goto cleanup; + } + + for (i = 0; i < ARRAY_SIZE(children); i++) + children[i].usage = cg_read_key_long(children[i].cgroup, + "cpu.stat", "usage_usec"); + + if (validate(children, ARRAY_SIZE(children))) + goto cleanup; + + ret = KSFT_PASS; +cleanup: + for (i = 0; i < ARRAY_SIZE(children); i++) { + cg_destroy(children[i].cgroup); + free(children[i].cgroup); + } + cg_destroy(parent); + free(parent); + + return ret; +} + +static pid_t weight_hog_ncpus(const struct cpu_hogger *child, int ncpus) +{ + long usage_seconds = 10; + struct cpu_hog_func_param param = { + .nprocs = ncpus, + .ts = { + .tv_sec = usage_seconds, + .tv_nsec = 0, + }, + .clock_type = CPU_HOG_CLOCK_WALL, + }; + return cg_run_nowait(child->cgroup, hog_cpus_timed, (void *)¶m); +} + +static pid_t weight_hog_all_cpus(const struct cpu_hogger *child) +{ + return weight_hog_ncpus(child, get_nprocs()); +} + +static int +overprovision_validate(const struct cpu_hogger *children, int num_children) +{ + int ret = KSFT_FAIL, i; + + for (i = 0; i < num_children - 1; i++) { + long delta; + + if (children[i + 1].usage <= children[i].usage) + goto cleanup; + + delta = children[i + 1].usage - children[i].usage; + if (!values_close(delta, children[0].usage, 35)) + goto cleanup; + } + + ret = KSFT_PASS; +cleanup: + return ret; +} + +/* + * First, this test creates the following hierarchy: + * A + * A/B cpu.weight = 50 + * A/C cpu.weight = 100 + * A/D cpu.weight = 150 + * + * A separate process is then created for each child cgroup which spawns as + * many threads as there are cores, and hogs each CPU as much as possible + * for some time interval. + * + * Once all of the children have exited, we verify that each child cgroup + * was given proportional runtime as informed by their cpu.weight. + */ +static int test_cpucg_weight_overprovisioned(const char *root) +{ + return run_cpucg_weight_test(root, weight_hog_all_cpus, + overprovision_validate); +} + +static pid_t weight_hog_one_cpu(const struct cpu_hogger *child) +{ + return weight_hog_ncpus(child, 1); +} + +static int +underprovision_validate(const struct cpu_hogger *children, int num_children) +{ + int ret = KSFT_FAIL, i; + + for (i = 0; i < num_children - 1; i++) { + if (!values_close(children[i + 1].usage, children[0].usage, 15)) + goto cleanup; + } + + ret = KSFT_PASS; +cleanup: + return ret; +} + +/* + * First, this test creates the following hierarchy: + * A + * A/B cpu.weight = 50 + * A/C cpu.weight = 100 + * A/D cpu.weight = 150 + * + * A separate process is then created for each child cgroup which spawns a + * single thread that hogs a CPU. The testcase is only run on systems that + * have at least one core per-thread in the child processes. + * + * Once all of the children have exited, we verify that each child cgroup + * had roughly the same runtime despite having different cpu.weight. + */ +static int test_cpucg_weight_underprovisioned(const char *root) +{ + // Only run the test if there are enough cores to avoid overprovisioning + // the system. + if (get_nprocs() < 4) + return KSFT_SKIP; + + return run_cpucg_weight_test(root, weight_hog_one_cpu, + underprovision_validate); +} + +static int +run_cpucg_nested_weight_test(const char *root, bool overprovisioned) +{ + int ret = KSFT_FAIL, i; + char *parent = NULL, *child = NULL; + struct cpu_hogger leaf[3] = {NULL}; + long nested_leaf_usage, child_usage; + int nprocs = get_nprocs(); + + if (!overprovisioned) { + if (nprocs < 4) + /* + * Only run the test if there are enough cores to avoid overprovisioning + * the system. + */ + return KSFT_SKIP; + nprocs /= 4; + } + + parent = cg_name(root, "cpucg_test"); + child = cg_name(parent, "cpucg_child"); + if (!parent || !child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + if (cg_write(parent, "cgroup.subtree_control", "+cpu")) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + if (cg_write(child, "cgroup.subtree_control", "+cpu")) + goto cleanup; + if (cg_write(child, "cpu.weight", "1000")) + goto cleanup; + + for (i = 0; i < ARRAY_SIZE(leaf); i++) { + const char *ancestor; + long weight; + + if (i == 0) { + ancestor = parent; + weight = 1000; + } else { + ancestor = child; + weight = 5000; + } + leaf[i].cgroup = cg_name_indexed(ancestor, "cpucg_leaf", i); + if (!leaf[i].cgroup) + goto cleanup; + + if (cg_create(leaf[i].cgroup)) + goto cleanup; + + if (cg_write_numeric(leaf[i].cgroup, "cpu.weight", weight)) + goto cleanup; + } + + for (i = 0; i < ARRAY_SIZE(leaf); i++) { + pid_t pid; + struct cpu_hog_func_param param = { + .nprocs = nprocs, + .ts = { + .tv_sec = 10, + .tv_nsec = 0, + }, + .clock_type = CPU_HOG_CLOCK_WALL, + }; + + pid = cg_run_nowait(leaf[i].cgroup, hog_cpus_timed, + (void *)¶m); + if (pid <= 0) + goto cleanup; + leaf[i].pid = pid; + } + + for (i = 0; i < ARRAY_SIZE(leaf); i++) { + int retcode; + + waitpid(leaf[i].pid, &retcode, 0); + if (!WIFEXITED(retcode)) + goto cleanup; + if (WEXITSTATUS(retcode)) + goto cleanup; + } + + for (i = 0; i < ARRAY_SIZE(leaf); i++) { + leaf[i].usage = cg_read_key_long(leaf[i].cgroup, + "cpu.stat", "usage_usec"); + if (leaf[i].usage <= 0) + goto cleanup; + } + + nested_leaf_usage = leaf[1].usage + leaf[2].usage; + if (overprovisioned) { + if (!values_close(leaf[0].usage, nested_leaf_usage, 15)) + goto cleanup; + } else if (!values_close(leaf[0].usage * 2, nested_leaf_usage, 15)) + goto cleanup; + + + child_usage = cg_read_key_long(child, "cpu.stat", "usage_usec"); + if (child_usage <= 0) + goto cleanup; + if (!values_close(child_usage, nested_leaf_usage, 1)) + goto cleanup; + + ret = KSFT_PASS; +cleanup: + for (i = 0; i < ARRAY_SIZE(leaf); i++) { + cg_destroy(leaf[i].cgroup); + free(leaf[i].cgroup); + } + cg_destroy(child); + free(child); + cg_destroy(parent); + free(parent); + + return ret; +} + +/* + * First, this test creates the following hierarchy: + * A + * A/B cpu.weight = 1000 + * A/C cpu.weight = 1000 + * A/C/D cpu.weight = 5000 + * A/C/E cpu.weight = 5000 + * + * A separate process is then created for each leaf, which spawn nproc threads + * that burn a CPU for a few seconds. + * + * Once all of those processes have exited, we verify that each of the leaf + * cgroups have roughly the same usage from cpu.stat. + */ +static int +test_cpucg_nested_weight_overprovisioned(const char *root) +{ + return run_cpucg_nested_weight_test(root, true); +} + +/* + * First, this test creates the following hierarchy: + * A + * A/B cpu.weight = 1000 + * A/C cpu.weight = 1000 + * A/C/D cpu.weight = 5000 + * A/C/E cpu.weight = 5000 + * + * A separate process is then created for each leaf, which nproc / 4 threads + * that burns a CPU for a few seconds. + * + * Once all of those processes have exited, we verify that each of the leaf + * cgroups have roughly the same usage from cpu.stat. + */ +static int +test_cpucg_nested_weight_underprovisioned(const char *root) +{ + return run_cpucg_nested_weight_test(root, false); +} + +/* + * This test creates a cgroup with some maximum value within a period, and + * verifies that a process in the cgroup is not overscheduled. + */ +static int test_cpucg_max(const char *root) +{ + int ret = KSFT_FAIL; + long usage_usec, user_usec; + long usage_seconds = 1; + long expected_usage_usec = usage_seconds * USEC_PER_SEC; + char *cpucg; + + cpucg = cg_name(root, "cpucg_test"); + if (!cpucg) + goto cleanup; + + if (cg_create(cpucg)) + goto cleanup; + + if (cg_write(cpucg, "cpu.max", "1000")) + goto cleanup; + + struct cpu_hog_func_param param = { + .nprocs = 1, + .ts = { + .tv_sec = usage_seconds, + .tv_nsec = 0, + }, + .clock_type = CPU_HOG_CLOCK_WALL, + }; + if (cg_run(cpucg, hog_cpus_timed, (void *)¶m)) + goto cleanup; + + usage_usec = cg_read_key_long(cpucg, "cpu.stat", "usage_usec"); + user_usec = cg_read_key_long(cpucg, "cpu.stat", "user_usec"); + if (user_usec <= 0) + goto cleanup; + + if (user_usec >= expected_usage_usec) + goto cleanup; + + if (values_close(usage_usec, expected_usage_usec, 95)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_destroy(cpucg); + free(cpucg); + + return ret; +} + +/* + * This test verifies that a process inside of a nested cgroup whose parent + * group has a cpu.max value set, is properly throttled. + */ +static int test_cpucg_max_nested(const char *root) +{ + int ret = KSFT_FAIL; + long usage_usec, user_usec; + long usage_seconds = 1; + long expected_usage_usec = usage_seconds * USEC_PER_SEC; + char *parent, *child; + + parent = cg_name(root, "cpucg_parent"); + child = cg_name(parent, "cpucg_child"); + if (!parent || !child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+cpu")) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_write(parent, "cpu.max", "1000")) + goto cleanup; + + struct cpu_hog_func_param param = { + .nprocs = 1, + .ts = { + .tv_sec = usage_seconds, + .tv_nsec = 0, + }, + .clock_type = CPU_HOG_CLOCK_WALL, + }; + if (cg_run(child, hog_cpus_timed, (void *)¶m)) + goto cleanup; + + usage_usec = cg_read_key_long(child, "cpu.stat", "usage_usec"); + user_usec = cg_read_key_long(child, "cpu.stat", "user_usec"); + if (user_usec <= 0) + goto cleanup; + + if (user_usec >= expected_usage_usec) + goto cleanup; + + if (values_close(usage_usec, expected_usage_usec, 95)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_destroy(child); + free(child); + cg_destroy(parent); + free(parent); + + return ret; +} + +#define T(x) { x, #x } +struct cpucg_test { + int (*fn)(const char *root); + const char *name; +} tests[] = { + T(test_cpucg_subtree_control), + T(test_cpucg_stats), + T(test_cpucg_weight_overprovisioned), + T(test_cpucg_weight_underprovisioned), + T(test_cpucg_nested_weight_overprovisioned), + T(test_cpucg_nested_weight_underprovisioned), + T(test_cpucg_max), + T(test_cpucg_max_nested), +}; +#undef T + +int main(int argc, char *argv[]) +{ + char root[PATH_MAX]; + int i, ret = EXIT_SUCCESS; + + if (cg_find_unified_root(root, sizeof(root))) + ksft_exit_skip("cgroup v2 isn't mounted\n"); + + if (cg_read_strstr(root, "cgroup.subtree_control", "cpu")) + if (cg_write(root, "cgroup.subtree_control", "+cpu")) + ksft_exit_skip("Failed to set cpu controller\n"); + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + switch (tests[i].fn(root)) { + 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\n", tests[i].name); + break; + } + } + + return ret; +} |