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 <linyongt...@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");
+}
--
2.20.1
