Before verify some complicated memory functionalities such as swap memory and THP, we need add some helper functions to controlling the cgroup (specifically, memcg).
These helper functions consist: Create and destroy individual cgroup for test cases attach and dettach the test process to specified cgroup Read swap size and thp size from testing cgroup
Signed-off-by: Yongting Lin linyongting@bytedance.com --- tools/testing/selftests/mshare/util.c | 128 ++++++++++++++++++++++++++ 1 file changed, 128 insertions(+)
diff --git a/tools/testing/selftests/mshare/util.c b/tools/testing/selftests/mshare/util.c index 75f6ff25aa2c..94fddaea2c56 100644 --- a/tools/testing/selftests/mshare/util.c +++ b/tools/testing/selftests/mshare/util.c @@ -121,3 +121,131 @@ int mshare_ioctl_munmap(int fd, size_t size)
return ioctl(fd, MSHAREFS_UNMAP, &munmap); } + +/* + * Helper functions for cgroup + */ + +#define CGROUP_BASE "/sys/fs/cgroup/" +#define CGROUP_TEST "mshare-test-XXXXXX" + +bool is_cgroup_v2; + +__attribute__((constructor)) +void get_cgroup_version(void) +{ + if (access(CGROUP_BASE "cgroup.controllers", F_OK) == 0) + is_cgroup_v2 = true; +} + +int create_mshare_test_cgroup(char *cgroup, size_t len) +{ + if (is_cgroup_v2) + snprintf(cgroup, len, "%s/%s", CGROUP_BASE, CGROUP_TEST); + else + snprintf(cgroup, len, "%s/memory/%s", CGROUP_BASE, CGROUP_TEST); + + char *path = mkdtemp(cgroup); + + if (!path) { + perror("mkdtemp"); + return -1; + } + + return 0; +} + +int remove_cgroup(char *cgroup) +{ + return rmdir(cgroup); +} + +int write_data_to_cgroup(char *cgroup, char *file, char *data) +{ + char filename[128]; + int fd; + int ret; + + snprintf(filename, sizeof(filename), "%s/%s", cgroup, file); + fd = open(filename, O_RDWR); + + if (fd == -1) + return -1; + + ret = write(fd, data, strlen(data)); + close(fd); + + return ret; +} + +int attach_to_cgroup(char *cgroup) +{ + char pid_str[32]; + + snprintf(pid_str, sizeof(pid_str), "%d", getpid()); + return write_data_to_cgroup(cgroup, "cgroup.procs", pid_str); +} + +/* + * Simplely, just move the pid to root memcg as avoid + * complicated consideration. + */ +int dettach_from_cgroup(char *cgroup) +{ + char pid_str[32]; + char *root_memcg; + + if (is_cgroup_v2) + root_memcg = CGROUP_BASE; + else + root_memcg = CGROUP_BASE "memory"; + + snprintf(pid_str, sizeof(pid_str), "%d", getpid()); + return write_data_to_cgroup(root_memcg, "cgroup.procs", pid_str); +} + +size_t read_data_from_cgroup(char *cgroup, char *file, char *field) +{ + char filename[128]; + FILE *fp; + char line[80]; + size_t size = -1; + + snprintf(filename, sizeof(filename), "%s/%s", cgroup, file); + fp = fopen(filename, "r"); + if (!fp) { + perror("fopen"); + return -1; + } + + while (fgets(line, sizeof(line), fp)) { + if (!strncmp(line, field, strlen(field))) { + char *value = line + strlen(field) + 1; + + size = atol(value); + break; + } + } + + fclose(fp); + + return size; +} + +size_t read_swap_from_cgroup(char *cgroup) +{ + if (is_cgroup_v2) + return read_data_from_cgroup(cgroup, "memory.stat", "pswpout"); + else + return read_data_from_cgroup(cgroup, "memory.stat", "swap"); +} + +size_t read_huge_from_cgroup(char *cgroup) +{ + if (is_cgroup_v2) + return read_data_from_cgroup(cgroup, "memory.stat", "file_thp") + + read_data_from_cgroup(cgroup, "memory.stat", "anon_thp") + + read_data_from_cgroup(cgroup, "memory.stat", "shmem_thp"); + else + return read_data_from_cgroup(cgroup, "memory.stat", "rss_huge"); +}