Add a kselftest test to ensure that the core-sched interface is working
correctly.
Co-developed-by: Chris Hyser <chris.hy...@oracle.com>
Signed-off-by: Chris Hyser <chris.hy...@oracle.com>
Tested-by: Julien Desfossez <jdesfos...@digitalocean.com>
Reviewed-by: Josh Don <josh...@google.com>
Signed-off-by: Josh Don <josh...@google.com>
Signed-off-by: Chris Hyser <chris.hy...@oracle.com>
Signed-off-by: Joel Fernandes (Google) <j...@joelfernandes.org>
---
tools/testing/selftests/sched/.gitignore | 1 +
tools/testing/selftests/sched/Makefile | 14 +
tools/testing/selftests/sched/config | 1 +
.../testing/selftests/sched/test_coresched.c | 716 ++++++++++++++++++
4 files changed, 732 insertions(+)
create mode 100644 tools/testing/selftests/sched/.gitignore
create mode 100644 tools/testing/selftests/sched/Makefile
create mode 100644 tools/testing/selftests/sched/config
create mode 100644 tools/testing/selftests/sched/test_coresched.c
diff --git a/tools/testing/selftests/sched/.gitignore
b/tools/testing/selftests/sched/.gitignore
new file mode 100644
index 000000000000..4660929b0b9a
--- /dev/null
+++ b/tools/testing/selftests/sched/.gitignore
@@ -0,0 +1 @@
+test_coresched
diff --git a/tools/testing/selftests/sched/Makefile
b/tools/testing/selftests/sched/Makefile
new file mode 100644
index 000000000000..e43b74fc5d7e
--- /dev/null
+++ b/tools/testing/selftests/sched/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
+CLANG_FLAGS += -no-integrated-as
+endif
+
+CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -Wl,-rpath=./ \
+ $(CLANG_FLAGS)
+LDLIBS += -lpthread
+
+TEST_GEN_FILES := test_coresched
+TEST_PROGS := test_coresched
+
+include ../lib.mk
diff --git a/tools/testing/selftests/sched/config
b/tools/testing/selftests/sched/config
new file mode 100644
index 000000000000..e8b09aa7c0c4
--- /dev/null
+++ b/tools/testing/selftests/sched/config
@@ -0,0 +1 @@
+CONFIG_SCHED_DEBUG=y
diff --git a/tools/testing/selftests/sched/test_coresched.c
b/tools/testing/selftests/sched/test_coresched.c
new file mode 100644
index 000000000000..4d18a0a727c8
--- /dev/null
+++ b/tools/testing/selftests/sched/test_coresched.c
@@ -0,0 +1,716 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Core-scheduling selftests.
+ *
+ * Copyright (C) 2020, Joel Fernandes.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#ifndef PR_SCHED_CORE_SHARE
+#define PR_SCHED_CORE_SHARE 59
+# define PR_SCHED_CORE_CLEAR 0
+# define PR_SCHED_CORE_SHARE_FROM 1
+# define PR_SCHED_CORE_SHARE_TO 2
+#endif
+
+#ifndef DEBUG_PRINT
+#define dprint(...)
+#else
+#define dprint(str, args...) printf("DEBUG: %s: " str "\n", __func__, ##args)
+#endif
+
+void print_banner(char *s)
+{
+ printf("coresched: %s: ", s);
+}
+
+void print_pass(void)
+{
+ printf("PASS\n");
+}
+
+void assert_cond(int cond, char *str)
+{
+ if (!cond) {
+ printf("Error: %s\n", str);
+ abort();
+ }
+}
+
+char *make_group_root(void)
+{
+ char *mntpath, *mnt;
+ int ret;
+
+ mntpath = malloc(50);
+ if (!mntpath) {
+ perror("Failed to allocate mntpath\n");
+ abort();
+ }
+
+ sprintf(mntpath, "/tmp/coresched-test-XXXXXX");
+ mnt = mkdtemp(mntpath);
+ if (!mnt) {
+ perror("Failed to create mount: ");
+ exit(-1);
+ }
+
+ ret = mount("nodev", mnt, "cgroup", 0, "cpu");
+ if (ret == -1) {
+ perror("Failed to mount cgroup: ");
+ exit(-1);
+ }
+
+ return mnt;
+}
+
+char *read_group_cookie(char *cgroup_path)
+{
+ char path[50] = {}, *val;
+ int fd;
+
+ sprintf(path, "%s/cpu.core_group_cookie", cgroup_path);
+ fd = open(path, O_RDONLY, 0666);
+ if (fd == -1) {
+ perror("Open of cgroup tag path failed: ");
+ abort();
+ }
+
+ val = calloc(1, 50);
+ if (read(fd, val, 50) == -1) {
+ perror("Failed to read group cookie: ");
+ abort();
+ }
+
+ val[strcspn(val, "\r\n")] = 0;
+
+ close(fd);
+ return val;
+}
+
+void assert_group_tag(char *cgroup_path, char *tag)
+{
+ char tag_path[50] = {}, rdbuf[8] = {};
+ int tfd;
+
+ sprintf(tag_path, "%s/cpu.core_tag", cgroup_path);
+ tfd = open(tag_path, O_RDONLY, 0666);
+ if (tfd == -1) {
+ perror("Open of cgroup tag path failed: ");
+ abort();
+ }
+
+ if (read(tfd, rdbuf, 1) != 1) {
+ perror("Failed to enable coresched on cgroup: ");
+ abort();
+ }
+
+ if (strcmp(rdbuf, tag)) {
+ printf("Group tag does not match (exp: %s, act: %s)\n", tag,
+ rdbuf);
+ abort();
+ }
+
+ if (close(tfd) == -1) {
+ perror("Failed to close tag fd: ");
+ abort();
+ }
+}
+
+void tag_group(char *cgroup_path)
+{
+ char tag_path[50];
+ int tfd;
+
+ sprintf(tag_path, "%s/cpu.core_tag", cgroup_path);
+ tfd = open(tag_path, O_WRONLY, 0666);
+ if (tfd == -1) {
+ perror("Open of cgroup tag path failed: ");
+ abort();
+ }
+
+ if (write(tfd, "1", 1) != 1) {
+ perror("Failed to enable coresched on cgroup: ");
+ abort();
+ }
+
+ if (close(tfd) == -1) {
+ perror("Failed to close tag fd: ");
+ abort();
+ }
+
+ assert_group_tag(cgroup_path, "1");
+}
+
+void untag_group(char *cgroup_path)
+{
+ char tag_path[50];
+ int tfd;
+
+ sprintf(tag_path, "%s/cpu.core_tag", cgroup_path);
+ tfd = open(tag_path, O_WRONLY, 0666);
+ if (tfd == -1) {
+ perror("Open of cgroup tag path failed: ");
+ abort();
+ }
+
+ if (write(tfd, "0", 1) != 1) {
+ perror("Failed to disable coresched on cgroup: ");
+ abort();
+ }
+
+ if (close(tfd) == -1) {
+ perror("Failed to close tag fd: ");
+ abort();
+ }
+
+ assert_group_tag(cgroup_path, "0");
+}
+
+char *make_group(char *parent, char *name)
+{
+ char *cgroup_path;
+ int ret;
+
+ if (!parent && !name)
+ return make_group_root();
+
+ cgroup_path = malloc(50);
+ if (!cgroup_path) {
+ perror("Failed to allocate cgroup_path\n");
+ abort();
+ }
+
+ /* Make the cgroup node for this group */
+ sprintf(cgroup_path, "%s/%s", parent, name);
+ ret = mkdir(cgroup_path, 0644);
+ if (ret == -1) {
+ perror("Failed to create group in cgroup: ");
+ abort();
+ }
+
+ return cgroup_path;
+}
+
+static void del_group(char *path)
+{
+ if (rmdir(path) != 0) {
+ printf("Removal of group failed\n");
+ abort();
+ }
+
+ free(path);
+}
+
+static void del_root_group(char *path)
+{
+ if (umount(path) != 0) {
+ perror("umount of cgroup failed\n");
+ abort();
+ }
+
+ if (rmdir(path) != 0) {
+ printf("Removal of group failed\n");
+ abort();
+ }
+
+ free(path);
+}
+
+void assert_group_cookie_equal(char *c1, char *c2)
+{
+ char *v1, *v2;
+
+ v1 = read_group_cookie(c1);
+ v2 = read_group_cookie(c2);
+ if (strcmp(v1, v2)) {
+ printf("Group cookies not equal\n");
+ abort();
+ }
+
+ free(v1);
+ free(v2);
+}
+
+void assert_group_cookie_not_equal(char *c1, char *c2)
+{
+ char *v1, *v2;
+
+ v1 = read_group_cookie(c1);
+ v2 = read_group_cookie(c2);
+ if (!strcmp(v1, v2)) {
+ printf("Group cookies equal\n");
+ abort();
+ }
+
+ free(v1);
+ free(v2);
+}
+
+void assert_group_cookie_not_zero(char *c1)
+{
+ char *v1 = read_group_cookie(c1);
+
+ v1[1] = 0;
+ if (!strcmp(v1, "0")) {
+ printf("Group cookie zero\n");
+ abort();
+ }
+ free(v1);
+}
+
+void assert_group_cookie_zero(char *c1)
+{
+ char *v1 = read_group_cookie(c1);
+
+ v1[1] = 0;
+ if (strcmp(v1, "0")) {
+ printf("Group cookie not zero");
+ abort();
+ }
+ free(v1);
+}
+
+struct task_state {
+ int pid_share;
+ char pid_str[50];
+ pthread_mutex_t m;
+ pthread_cond_t cond;
+ pthread_cond_t cond_par;
+};
+
+struct task_state *add_task(char *p)
+{
+ struct task_state *mem;
+ pthread_mutexattr_t am;
+ pthread_condattr_t a;
+ char tasks_path[50];
+ int tfd, pid, ret;
+
+ sprintf(tasks_path, "%s/tasks", p);
+ tfd = open(tasks_path, O_WRONLY, 0666);
+ if (tfd == -1) {
+ perror("Open of cgroup tasks path failed: ");
+ abort();
+ }
+
+ mem = mmap(NULL, sizeof(*mem), PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+ memset(mem, 0, sizeof(*mem));
+
+ pthread_condattr_init(&a);
+ pthread_condattr_setpshared(&a, PTHREAD_PROCESS_SHARED);
+ pthread_mutexattr_init(&am);
+ pthread_mutexattr_setpshared(&am, PTHREAD_PROCESS_SHARED);
+
+ pthread_cond_init(&mem->cond, &a);
+ pthread_cond_init(&mem->cond_par, &a);
+ pthread_mutex_init(&mem->m, &am);
+
+ pid = fork();
+ if (pid == 0) {
+ while (1) {
+ pthread_mutex_lock(&mem->m);
+ while (!mem->pid_share)
+ pthread_cond_wait(&mem->cond, &mem->m);
+
+ pid = mem->pid_share;
+ mem->pid_share = 0;
+
+ if (pid == -1) {
+ if (prctl
+ (PR_SCHED_CORE_SHARE, PR_SCHED_CORE_CLEAR,
+ getpid(), 0, 0))
+ perror
+ ("prctl() PR_SCHED_CORE_CLEAR
failed");
+ } else {
+ if (prctl
+ (PR_SCHED_CORE_SHARE,
+ PR_SCHED_CORE_SHARE_FROM, pid, 0, 0))
+ perror
+ ("prctl() PR_SCHED_CORE_SHARE_FROM
failed");
+ }
+ pthread_mutex_unlock(&mem->m);
+ pthread_cond_signal(&mem->cond_par);
+ }
+ }
+
+ sprintf(mem->pid_str, "%d", pid);
+ dprint("add task %d to group %s", pid, p);
+
+ ret = write(tfd, mem->pid_str, strlen(mem->pid_str));
+ assert_cond(ret != -1, "Failed to write pid into tasks");
+
+ close(tfd);
+ return mem;
+}
+
+/* Make t1 share with t2 */
+void make_tasks_share(struct task_state *t1, struct task_state *t2)
+{
+ int p2 = atoi(t2->pid_str);
+
+ dprint("task %s %s", t1->pid_str, t2->pid_str);
+
+ pthread_mutex_lock(&t1->m);
+ t1->pid_share = p2;
+ pthread_mutex_unlock(&t1->m);
+
+ pthread_cond_signal(&t1->cond);
+
+ pthread_mutex_lock(&t1->m);
+ while (t1->pid_share)
+ pthread_cond_wait(&t1->cond_par, &t1->m);
+ pthread_mutex_unlock(&t1->m);
+}
+
+/* Make t1 share with t2 */
+void reset_task_cookie(struct task_state *t1)
+{
+ dprint("task %s", t1->pid_str);
+
+ pthread_mutex_lock(&t1->m);
+ t1->pid_share = -1;
+ pthread_mutex_unlock(&t1->m);
+
+ pthread_cond_signal(&t1->cond);
+
+ pthread_mutex_lock(&t1->m);
+ while (t1->pid_share)
+ pthread_cond_wait(&t1->cond_par, &t1->m);
+ pthread_mutex_unlock(&t1->m);
+}
+
+char *get_task_core_cookie(char *pid)
+{
+ char proc_path[50];
+ int found = 0;
+ char *line;
+ int i, j;
+ FILE *fp;
+
+ line = malloc(1024);
+ assert_cond(!!line, "Failed to alloc memory");
+
+ sprintf(proc_path, "/proc/%s/sched", pid);
+
+ fp = fopen(proc_path, "r");
+ while ((fgets(line, 1024, fp)) != NULL) {
+ if (!strstr(line, "core_cookie"))
+ continue;
+
+ for (j = 0, i = 0; i < 1024 && line[i] != '\0'; i++)
+ if (line[i] >= '0' && line[i] <= '9')
+ line[j++] = line[i];
+ line[j] = '\0';
+ found = 1;
+ break;
+ }
+
+ fclose(fp);
+
+ if (found)
+ return line;
+
+ free(line);
+ printf("core_cookie not found. Enable SCHED_DEBUG?\n");
+ abort();
+ return NULL;
+}
+
+void assert_tasks_share(struct task_state *t1, struct task_state *t2)
+{
+ char *c1, *c2;
+
+ c1 = get_task_core_cookie(t1->pid_str);
+ c2 = get_task_core_cookie(t2->pid_str);
+ dprint("check task (%s) cookie (%s) == task (%s) cookie (%s)",
+ t1->pid_str, c1, t2->pid_str, c2);
+ assert_cond(!strcmp(c1, c2), "Tasks don't share cookie");
+ free(c1);
+ free(c2);
+}
+
+void assert_tasks_dont_share(struct task_state *t1, struct task_state *t2)
+{
+ char *c1, *c2;
+
+ c1 = get_task_core_cookie(t1->pid_str);
+ c2 = get_task_core_cookie(t2->pid_str);
+ dprint("check task (%s) cookie (%s) != task (%s) cookie (%s)",
+ t1->pid_str, c1, t2->pid_str, c2);
+ assert_cond(strcmp(c1, c2), "Tasks don't share cookie");
+ free(c1);
+ free(c2);
+}
+
+void assert_task_has_cookie(char *pid)
+{
+ char *tk;
+
+ tk = get_task_core_cookie(pid);
+
+ assert_cond(strcmp(tk, "0"), "Task does not have cookie");
+
+ free(tk);
+}
+
+void kill_task(struct task_state *t)
+{
+ int pid = atoi(t->pid_str);
+
+ kill(pid, SIGKILL);
+ waitpid(pid, NULL, 0);
+}
+
+/*
+ * Test that a group's children have a cookie inherrited
+ * from their parent group _after_ the parent was tagged.
+ *
+ * p ----- c1 - c11
+ * \ c2 - c22
+ */
+static void test_cgroup_parent_child_tag_inherit(char *root)
+{
+ char *p, *c1, *c11, *c2, *c22;
+
+ print_banner("TEST-CGROUP-PARENT-CHILD-TAG");
+
+ p = make_group(root, "p");
+ assert_group_cookie_zero(p);
+
+ c1 = make_group(p, "c1");
+ assert_group_tag(c1, "0"); /* Child tag is "0" but inherits cookie
from parent. */
+ assert_group_cookie_zero(c1);
+ assert_group_cookie_equal(c1, p);
+
+ c11 = make_group(c1, "c11");
+ assert_group_tag(c11, "0");
+ assert_group_cookie_zero(c11);
+ assert_group_cookie_equal(c11, p);
+
+ c2 = make_group(p, "c2");
+ assert_group_tag(c2, "0");
+ assert_group_cookie_zero(c2);
+ assert_group_cookie_equal(c2, p);
+
+ tag_group(p);
+
+ /* Verify c1 got the cookie */
+ assert_group_tag(c1, "0");
+ assert_group_cookie_not_zero(c1);
+ assert_group_cookie_equal(c1, p);
+
+ /* Verify c2 got the cookie */
+ assert_group_tag(c2, "0");
+ assert_group_cookie_not_zero(c2);
+ assert_group_cookie_equal(c2, p);
+
+ /* Verify c11 got the cookie */
+ assert_group_tag(c11, "0");
+ assert_group_cookie_not_zero(c11);
+ assert_group_cookie_equal(c11, p);
+
+ /*
+ * Verify c22 which is a nested group created
+ * _after_ tagging got the cookie.
+ */
+ c22 = make_group(c2, "c22");
+
+ assert_group_tag(c22, "0");
+ assert_group_cookie_not_zero(c22);
+ assert_group_cookie_equal(c22, c1);
+ assert_group_cookie_equal(c22, c11);
+ assert_group_cookie_equal(c22, c2);
+ assert_group_cookie_equal(c22, p);
+
+ del_group(c22);
+ del_group(c11);
+ del_group(c1);
+ del_group(c2);
+ del_group(p);
+ print_pass();
+}
+
+/*
+ * Test that a tagged group's children have a cookie inherrited
+ * from their parent group.
+ */
+static void test_cgroup_parent_tag_child_inherit(char *root)
+{
+ char *p, *c1, *c2, *c3;
+
+ print_banner("TEST-CGROUP-PARENT-TAG-CHILD-INHERIT");
+
+ p = make_group(root, "p");
+ assert_group_cookie_zero(p);
+ tag_group(p);
+ assert_group_cookie_not_zero(p);
+
+ c1 = make_group(p, "c1");
+ assert_group_cookie_not_zero(c1);
+ /* Child tag is "0" but it inherits cookie from parent. */
+ assert_group_tag(c1, "0");
+ assert_group_cookie_equal(c1, p);
+
+ c2 = make_group(p, "c2");
+ assert_group_tag(c2, "0");
+ assert_group_cookie_equal(c2, p);
+ assert_group_cookie_equal(c1, c2);
+
+ c3 = make_group(c1, "c3");
+ assert_group_tag(c3, "0");
+ assert_group_cookie_equal(c3, p);
+ assert_group_cookie_equal(c1, c3);
+
+ del_group(c3);
+ del_group(c1);
+ del_group(c2);
+ del_group(p);
+ print_pass();
+}
+
+static void test_prctl_in_group(char *root)
+{
+ char *p;
+ struct task_state *tsk1, *tsk2, *tsk3;
+
+ print_banner("TEST-PRCTL-IN-GROUP");
+
+ p = make_group(root, "p");
+ assert_group_cookie_zero(p);
+ tag_group(p);
+ assert_group_cookie_not_zero(p);
+
+ tsk1 = add_task(p);
+ assert_task_has_cookie(tsk1->pid_str);
+
+ tsk2 = add_task(p);
+ assert_task_has_cookie(tsk2->pid_str);
+
+ tsk3 = add_task(p);
+ assert_task_has_cookie(tsk3->pid_str);
+
+ /* tsk2 share with tsk3 -- both get disconnected from CGroup. */
+ make_tasks_share(tsk2, tsk3);
+ assert_task_has_cookie(tsk2->pid_str);
+ assert_task_has_cookie(tsk3->pid_str);
+ assert_tasks_share(tsk2, tsk3);
+ assert_tasks_dont_share(tsk1, tsk2);
+ assert_tasks_dont_share(tsk1, tsk3);
+
+ /* now reset tsk3 -- get connected back to CGroup. */
+ reset_task_cookie(tsk3);
+ assert_task_has_cookie(tsk3->pid_str);
+ assert_tasks_dont_share(tsk2, tsk3);
+ assert_tasks_share(tsk1, tsk3); // tsk3 is back.
+ assert_tasks_dont_share(tsk1, tsk2); // but tsk2 is still zombie
+
+ /* now reset tsk2 as well to get it connected back to CGroup. */
+ reset_task_cookie(tsk2);
+ assert_task_has_cookie(tsk2->pid_str);
+ assert_tasks_share(tsk2, tsk3);
+ assert_tasks_share(tsk1, tsk3);
+ assert_tasks_share(tsk1, tsk2);
+
+ /* Test the rest of the cases (2 to 4)
+ *
+ * t1 joining t2
+ * CASE 1:
+ * before 0 0
+ * after new cookie new cookie
+ *
+ * CASE 2:
+ * before X (non-zero) 0
+ * after 0 0
+ *
+ * CASE 3:
+ * before 0 X (non-zero)
+ * after X X
+ *
+ * CASE 4:
+ * before Y (non-zero) X (non-zero)
+ * after X X
+ */
+
+ /* case 2: */
+ dprint("case 2");
+ make_tasks_share(tsk1, tsk1);
+ assert_tasks_dont_share(tsk1, tsk2);
+ assert_tasks_dont_share(tsk1, tsk3);
+ assert_task_has_cookie(tsk1->pid_str);
+ make_tasks_share(tsk1, tsk2); /* Will reset the task cookie. */
+ assert_task_has_cookie(tsk1->pid_str);
+ assert_task_has_cookie(tsk2->pid_str);
+
+ /* case 3: */
+ dprint("case 3");
+ make_tasks_share(tsk2, tsk2);
+ assert_tasks_dont_share(tsk2, tsk1);
+ assert_tasks_dont_share(tsk2, tsk3);
+ assert_task_has_cookie(tsk2->pid_str);
+ make_tasks_share(tsk1, tsk2);
+ assert_task_has_cookie(tsk1->pid_str);
+ assert_task_has_cookie(tsk2->pid_str);
+ assert_tasks_share(tsk1, tsk2);
+ assert_tasks_dont_share(tsk1, tsk3);
+ reset_task_cookie(tsk1);
+ reset_task_cookie(tsk2);
+
+ /* case 4: */
+ dprint("case 4");
+ assert_tasks_share(tsk1, tsk2);
+ assert_task_has_cookie(tsk1->pid_str);
+ assert_task_has_cookie(tsk2->pid_str);
+ make_tasks_share(tsk1, tsk1);
+ assert_task_has_cookie(tsk1->pid_str);
+ make_tasks_share(tsk2, tsk2);
+ assert_task_has_cookie(tsk2->pid_str);
+ assert_tasks_dont_share(tsk1, tsk2);
+ make_tasks_share(tsk1, tsk2);
+ assert_task_has_cookie(tsk1->pid_str);
+ assert_task_has_cookie(tsk2->pid_str);
+ assert_tasks_share(tsk1, tsk2);
+ assert_tasks_dont_share(tsk1, tsk3);
+ reset_task_cookie(tsk1);
+ reset_task_cookie(tsk2);
+
+ kill_task(tsk1);
+ kill_task(tsk2);
+ kill_task(tsk3);
+ del_group(p);
+ print_pass();
+}
+
+int main(int argc, char *argv[])
+{
+ char *root;
+
+ if (argc > 1)
+ root = argv[1];
+ else
+ root = make_group(NULL, NULL);
+
+ test_cgroup_parent_tag_child_inherit(root);
+ test_cgroup_parent_child_tag_inherit(root);
+ test_prctl_in_group(root);
+
+ if (argc <= 1)
+ del_root_group(root);
+ return 0;
+}
--
2.30.0.280.ga3ce27912f-goog
