On 05/10/2018 10:37 AM, Roman Gushchin wrote: > Cgroups are used for controlling the physical resource distribution > (memory, CPU, io, etc) and often are used as basic building blocks > for large distributed computing systems. Even small differences > in the actual behavior may lead to significant incidents. > > The codebase is under the active development, which will unlikely > stop at any time soon. Also it's scattered over different > kernel subsystems, which makes regressions more probable. > > Given that, the lack of any tests is crying. > > This patch implements some basic tests for the memory controller, > as well as a minimal required framework. > It doesn't pretend for a very good coverage, but pretends > to be a starting point. > > Hopefully, any following significant changes will > include corresponding tests. > > Tests for CPU and io controllers, as well as cgroup core > are next in the todo list. > > Signed-off-by: Roman Gushchin <[email protected]> > Cc: Tejun Heo <[email protected]> > Cc: Shuah Khan <[email protected]> > Cc: Johannes Weiner <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Mike Rapoport <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > --- > tools/testing/selftests/Makefile | 1 + > tools/testing/selftests/cgroup/Makefile | 10 + > tools/testing/selftests/cgroup/cgroup_util.c | 317 ++++++++++ > tools/testing/selftests/cgroup/cgroup_util.h | 40 ++ > tools/testing/selftests/cgroup/test_memcontrol.c | 741 > +++++++++++++++++++++++ > 5 files changed, 1109 insertions(+) > create mode 100644 tools/testing/selftests/cgroup/Makefile > create mode 100644 tools/testing/selftests/cgroup/cgroup_util.c > create mode 100644 tools/testing/selftests/cgroup/cgroup_util.h > create mode 100644 tools/testing/selftests/cgroup/test_memcontrol.c > > diff --git a/tools/testing/selftests/Makefile > b/tools/testing/selftests/Makefile > index 32aafa92074c..24d0331d6c11 100644 > --- a/tools/testing/selftests/Makefile > +++ b/tools/testing/selftests/Makefile > @@ -3,6 +3,7 @@ TARGETS = android > TARGETS += bpf > TARGETS += breakpoints > TARGETS += capabilities > +TARGETS += cgroup > TARGETS += cpufreq > TARGETS += cpu-hotplug > TARGETS += efivarfs > diff --git a/tools/testing/selftests/cgroup/Makefile > b/tools/testing/selftests/cgroup/Makefile > new file mode 100644 > index 000000000000..f7a31392eb2f > --- /dev/null > +++ b/tools/testing/selftests/cgroup/Makefile > @@ -0,0 +1,10 @@ > +# SPDX-License-Identifier: GPL-2.0 > +CFLAGS += -Wall > + > +all: > + > +TEST_GEN_PROGS = test_memcontrol > + > +include ../lib.mk > + > +$(OUTPUT)/test_memcontrol: cgroup_util.c > diff --git a/tools/testing/selftests/cgroup/cgroup_util.c > b/tools/testing/selftests/cgroup/cgroup_util.c > new file mode 100644 > index 000000000000..a938b6c8b55a > --- /dev/null > +++ b/tools/testing/selftests/cgroup/cgroup_util.c > @@ -0,0 +1,317 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#define _GNU_SOURCE > + > +#include <errno.h> > +#include <fcntl.h> > +#include <linux/limits.h> > +#include <signal.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <sys/stat.h> > +#include <sys/types.h> > +#include <sys/wait.h> > +#include <unistd.h> > + > +#include "cgroup_util.h" > + > +static ssize_t read_text(const char *path, char *buf, size_t max_len) > +{ > + ssize_t len; > + int fd; > + > + fd = open(path, O_RDONLY); > + if (fd < 0) > + return fd; > + > + len = read(fd, buf, max_len - 1); > + if (len < 0) > + goto out; > + > + buf[len] = 0; > +out: > + close(fd); > + return len; > +} > + > +static ssize_t write_text(const char *path, char *buf, size_t len) > +{ > + int fd; > + > + fd = open(path, O_WRONLY | O_APPEND); > + if (fd < 0) > + return fd; > + > + len = write(fd, buf, len); > + if (len < 0) { > + close(fd); > + return len; > + } > + > + close(fd); > + > + return len; > +} > + > +char *cg_name(const char *root, const char *name) > +{ > + size_t len = strlen(root) + strlen(name) + 2; > + char *ret = malloc(len); > + > + if (name) > + snprintf(ret, len, "%s/%s", root, name); > + > + return ret; > +} > + > +char *cg_name_indexed(const char *root, const char *name, int index) > +{ > + size_t len = strlen(root) + strlen(name) + 10; > + char *ret = malloc(len); > + > + if (name) > + snprintf(ret, len, "%s/%s_%d", root, name, index); > + > + return ret; > +} > + > +int cg_read(const char *cgroup, const char *control, char *buf, size_t len) > +{ > + char path[PATH_MAX]; > + > + snprintf(path, sizeof(path), "%s/%s", cgroup, control); > + > + if (read_text(path, buf, len) >= 0) > + return 0; > + > + return -1; > +} > + > +int cg_read_strcmp(const char *cgroup, const char *control, > + const char *expected) > +{ > + size_t size = strlen(expected) + 1; > + char *buf; > + > + buf = malloc(size); > + if (!buf) > + return -1; > + > + if (cg_read(cgroup, control, buf, size)) > + return -1; > + > + return strcmp(expected, buf); > +} > + > +int cg_read_strstr(const char *cgroup, const char *control, const char > *needle) > +{ > + char buf[PAGE_SIZE]; > + > + if (cg_read(cgroup, control, buf, sizeof(buf))) > + return -1; > + > + return strstr(buf, needle) ? 0 : -1; > +} > + > +long cg_read_long(const char *cgroup, const char *control) > +{ > + char buf[128]; > + > + if (cg_read(cgroup, control, buf, sizeof(buf))) > + return -1; > + > + return atol(buf); > +} > + > +long cg_read_key_long(const char *cgroup, const char *control, const char > *key) > +{ > + char buf[PAGE_SIZE]; > + char *ptr; > + > + if (cg_read(cgroup, control, buf, sizeof(buf))) > + return -1; > + > + ptr = strstr(buf, key); > + if (!ptr) > + return -1; > + > + return atol(ptr + strlen(key)); > +} > + > +int cg_write(const char *cgroup, const char *control, char *buf) > +{ > + char path[PATH_MAX]; > + size_t len = strlen(buf); > + > + snprintf(path, sizeof(path), "%s/%s", cgroup, control); > + > + if (write_text(path, buf, len) == len) > + return 0; > + > + return -1; > +} > + > +int cg_find_unified_root(char *root, size_t len) > +{ > + char buf[10 * PAGE_SIZE]; > + char *fs, *mount, *type; > + const char delim[] = "\n\t "; > + > + if (read_text("/proc/self/mounts", buf, sizeof(buf)) <= 0) > + return -1; > + > + /* > + * Example: > + * cgroup /sys/fs/cgroup cgroup2 rw,seclabel,noexec,relatime 0 0 > + */ > + for (fs = strtok(buf, delim); fs; fs = strtok(NULL, delim)) { > + mount = strtok(NULL, delim); > + type = strtok(NULL, delim); > + strtok(NULL, delim); > + strtok(NULL, delim); > + strtok(NULL, delim); > + > + if (strcmp(fs, "cgroup") == 0 && > + strcmp(type, "cgroup2") == 0) { > + strncpy(root, mount, len); > + return 0; > + } > + } > + > + return -1; > +} > + > +int cg_create(const char *cgroup) > +{ > + return mkdir(cgroup, 0644); > +} > + > +static int cg_killall(const char *cgroup) > +{ > + char buf[PAGE_SIZE]; > + char *ptr = buf; > + > + if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf))) > + return -1; > + > + while (ptr < buf + sizeof(buf)) { > + int pid = strtol(ptr, &ptr, 10); > + > + if (pid == 0) > + break; > + if (*ptr) > + ptr++; > + else > + break; > + if (kill(pid, SIGKILL)) > + return -1; > + } > + > + return 0; > +} > + > +int cg_destroy(const char *cgroup) > +{ > + int ret; > + > +retry: > + ret = rmdir(cgroup); > + if (ret && errno == EBUSY) { > + ret = cg_killall(cgroup); > + if (ret) > + return ret; > + usleep(100); > + goto retry; > + } > + > + if (ret && errno == ENOENT) > + ret = 0; > + > + return ret; > +} > + > +int cg_run(const char *cgroup, > + int (*fn)(const char *cgroup, void *arg), > + void *arg) > +{ > + int pid, retcode; > + > + pid = fork(); > + if (pid < 0) { > + return pid; > + } else if (pid == 0) { > + char buf[64]; > + > + snprintf(buf, sizeof(buf), "%d", getpid()); > + if (cg_write(cgroup, "cgroup.procs", buf)) > + exit(EXIT_FAILURE); > + exit(fn(cgroup, arg)); > + } else { > + waitpid(pid, &retcode, 0); > + if (WIFEXITED(retcode)) > + return WEXITSTATUS(retcode); > + else > + return -1; > + } > +} > + > +int cg_run_nowait(const char *cgroup, > + int (*fn)(const char *cgroup, void *arg), > + void *arg) > +{ > + int pid; > + > + pid = fork(); > + if (pid == 0) { > + char buf[64]; > + > + snprintf(buf, sizeof(buf), "%d", getpid()); > + if (cg_write(cgroup, "cgroup.procs", buf)) > + exit(EXIT_FAILURE); > + exit(fn(cgroup, arg)); > + } > + > + return pid; > +} > + > +int get_temp_fd(void) > +{ > + return open(".", O_TMPFILE | O_RDWR | O_EXCL); > +} > + > +int alloc_pagecache(int fd, size_t size) > +{ > + char buf[PAGE_SIZE]; > + struct stat st; > + int i; > + > + if (fstat(fd, &st)) > + goto cleanup; > + > + size += st.st_size; > + > + if (ftruncate(fd, size)) > + goto cleanup; > + > + for (i = 0; i < size; i += sizeof(buf)) > + read(fd, buf, sizeof(buf)); > + > + return 0; > + > +cleanup: > + return -1; > +} > + > +int alloc_anon(const char *cgroup, void *arg) > +{ > + size_t size = (unsigned long)arg; > + char *buf, *ptr; > + > + buf = malloc(size); > + for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE) > + *ptr = 0; > + > + free(buf); > + return 0; > +} > diff --git a/tools/testing/selftests/cgroup/cgroup_util.h > b/tools/testing/selftests/cgroup/cgroup_util.h > new file mode 100644 > index 000000000000..000de075d3d8 > --- /dev/null > +++ b/tools/testing/selftests/cgroup/cgroup_util.h > @@ -0,0 +1,40 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#include <stdlib.h> > + > +#define PAGE_SIZE 4096 > + > +#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) > + > +#define MB(x) (x << 20) > + > +/* > + * 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; > +} > + > +extern int cg_find_unified_root(char *root, size_t len); > +extern char *cg_name(const char *root, const char *name); > +extern char *cg_name_indexed(const char *root, const char *name, int index); > +extern int cg_create(const char *cgroup); > +extern int cg_destroy(const char *cgroup); > +extern int cg_read(const char *cgroup, const char *control, > + char *buf, size_t len); > +extern int cg_read_strcmp(const char *cgroup, const char *control, > + const char *expected); > +extern int cg_read_strstr(const char *cgroup, const char *control, > + const char *needle); > +extern long cg_read_long(const char *cgroup, const char *control); > +long cg_read_key_long(const char *cgroup, const char *control, const char > *key); > +extern int cg_write(const char *cgroup, const char *control, char *buf); > +extern int cg_run(const char *cgroup, > + int (*fn)(const char *cgroup, void *arg), > + void *arg); > +extern int cg_run_nowait(const char *cgroup, > + int (*fn)(const char *cgroup, void *arg), > + void *arg); > +extern int get_temp_fd(void); > +extern int alloc_pagecache(int fd, size_t size); > +extern int alloc_anon(const char *cgroup, void *arg); > diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c > b/tools/testing/selftests/cgroup/test_memcontrol.c > new file mode 100644 > index 000000000000..b6bbc4c1adc3 > --- /dev/null > +++ b/tools/testing/selftests/cgroup/test_memcontrol.c > @@ -0,0 +1,741 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#define _GNU_SOURCE > + > +#include <linux/limits.h> > +#include <fcntl.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <sys/stat.h> > +#include <sys/types.h> > +#include <unistd.h> > + > +#include "../kselftest.h" > +#include "cgroup_util.h" > + > +/* > + * Can't use KSFT_ values, > + * because there is no difference between SKIP and PASS values. > + */ > +enum test_result { > + TEST_SKIP, > + TEST_FAIL, > + TEST_PASS, > +}; > +
Please check linux-kselftest next - You will see thet SKIP handling patches in there. Please clean this up before they get into 4.18-rc1 thanks, -- Shuah
