From 11318989c381d2b08b4e361a03df09d54434b26c Mon Sep 17 00:00:00 2001 From: Michal Koutný Date: Fri, 4 Oct 2019 12:57:42 +0200 Subject: selftests: cgroup: Add task migration tests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add two new tests that verify that thread and threadgroup migrations work as expected. Signed-off-by: Michal Koutný Signed-off-by: Tejun Heo --- tools/testing/selftests/cgroup/Makefile | 2 +- tools/testing/selftests/cgroup/cgroup_util.c | 26 +++++ tools/testing/selftests/cgroup/cgroup_util.h | 2 + tools/testing/selftests/cgroup/test_core.c | 146 +++++++++++++++++++++++++++ 4 files changed, 175 insertions(+), 1 deletion(-) (limited to 'tools/testing/selftests/cgroup') diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile index 8d369b6a2069..1c9179400be0 100644 --- a/tools/testing/selftests/cgroup/Makefile +++ b/tools/testing/selftests/cgroup/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -CFLAGS += -Wall +CFLAGS += -Wall -pthread all: diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index f6573eac1365..8f7131dcf1ff 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -158,6 +158,22 @@ long cg_read_key_long(const char *cgroup, const char *control, const char *key) return atol(ptr + strlen(key)); } +long cg_read_lc(const char *cgroup, const char *control) +{ + char buf[PAGE_SIZE]; + const char delim[] = "\n"; + char *line; + long cnt = 0; + + if (cg_read(cgroup, control, buf, sizeof(buf))) + return -1; + + for (line = strtok(buf, delim); line; line = strtok(NULL, delim)) + cnt++; + + return cnt; +} + int cg_write(const char *cgroup, const char *control, char *buf) { char path[PATH_MAX]; @@ -424,3 +440,13 @@ ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t return read_text(path, buf, size); } + +int proc_read_strstr(int pid, bool thread, const char *item, const char *needle) +{ + char buf[PAGE_SIZE]; + + if (proc_read_text(pid, thread, item, buf, sizeof(buf)) < 0) + return -1; + + return strstr(buf, needle) ? 0 : -1; +} diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h index 27ff21d82af1..49c54fbdb229 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.h +++ b/tools/testing/selftests/cgroup/cgroup_util.h @@ -30,6 +30,7 @@ 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 long cg_read_lc(const char *cgroup, const char *control); 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), @@ -48,3 +49,4 @@ extern int set_oom_adj_score(int pid, int score); extern int cg_wait_for_proc_count(const char *cgroup, int count); extern int cg_killall(const char *cgroup); extern ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size); +extern int proc_read_strstr(int pid, bool thread, const char *item, const char *needle); diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c index 79053a4f4783..c5ca669feb2b 100644 --- a/tools/testing/selftests/cgroup/test_core.c +++ b/tools/testing/selftests/cgroup/test_core.c @@ -5,6 +5,9 @@ #include #include #include +#include +#include +#include #include "../kselftest.h" #include "cgroup_util.h" @@ -354,6 +357,147 @@ cleanup: return ret; } +static void *dummy_thread_fn(void *arg) +{ + return (void *)(size_t)pause(); +} + +/* + * Test threadgroup migration. + * All threads of a process are migrated together. + */ +static int test_cgcore_proc_migration(const char *root) +{ + int ret = KSFT_FAIL; + int t, c_threads, n_threads = 13; + char *src = NULL, *dst = NULL; + pthread_t threads[n_threads]; + + src = cg_name(root, "cg_src"); + dst = cg_name(root, "cg_dst"); + if (!src || !dst) + goto cleanup; + + if (cg_create(src)) + goto cleanup; + if (cg_create(dst)) + goto cleanup; + + if (cg_enter_current(src)) + goto cleanup; + + for (c_threads = 0; c_threads < n_threads; ++c_threads) { + if (pthread_create(&threads[c_threads], NULL, dummy_thread_fn, NULL)) + goto cleanup; + } + + cg_enter_current(dst); + if (cg_read_lc(dst, "cgroup.threads") != n_threads + 1) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + for (t = 0; t < c_threads; ++t) { + pthread_cancel(threads[t]); + } + + for (t = 0; t < c_threads; ++t) { + pthread_join(threads[t], NULL); + } + + cg_enter_current(root); + + if (dst) + cg_destroy(dst); + if (src) + cg_destroy(src); + free(dst); + free(src); + return ret; +} + +static void *migrating_thread_fn(void *arg) +{ + int g, i, n_iterations = 1000; + char **grps = arg; + char lines[3][PATH_MAX]; + + for (g = 1; g < 3; ++g) + snprintf(lines[g], sizeof(lines[g]), "0::%s", grps[g] + strlen(grps[0])); + + for (i = 0; i < n_iterations; ++i) { + cg_enter_current_thread(grps[(i % 2) + 1]); + + if (proc_read_strstr(0, 1, "cgroup", lines[(i % 2) + 1])) + return (void *)-1; + } + return NULL; +} + +/* + * Test single thread migration. + * Threaded cgroups allow successful migration of a thread. + */ +static int test_cgcore_thread_migration(const char *root) +{ + int ret = KSFT_FAIL; + char *dom = NULL; + char line[PATH_MAX]; + char *grps[3] = { (char *)root, NULL, NULL }; + pthread_t thr; + void *retval; + + dom = cg_name(root, "cg_dom"); + grps[1] = cg_name(root, "cg_dom/cg_src"); + grps[2] = cg_name(root, "cg_dom/cg_dst"); + if (!grps[1] || !grps[2] || !dom) + goto cleanup; + + if (cg_create(dom)) + goto cleanup; + if (cg_create(grps[1])) + goto cleanup; + if (cg_create(grps[2])) + goto cleanup; + + if (cg_write(grps[1], "cgroup.type", "threaded")) + goto cleanup; + if (cg_write(grps[2], "cgroup.type", "threaded")) + goto cleanup; + + if (cg_enter_current(grps[1])) + goto cleanup; + + if (pthread_create(&thr, NULL, migrating_thread_fn, grps)) + goto cleanup; + + if (pthread_join(thr, &retval)) + goto cleanup; + + if (retval) + goto cleanup; + + snprintf(line, sizeof(line), "0::%s", grps[1] + strlen(grps[0])); + if (proc_read_strstr(0, 1, "cgroup", line)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_enter_current(root); + if (grps[2]) + cg_destroy(grps[2]); + if (grps[1]) + cg_destroy(grps[1]); + if (dom) + cg_destroy(dom); + free(grps[2]); + free(grps[1]); + free(dom); + return ret; +} + #define T(x) { x, #x } struct corecg_test { int (*fn)(const char *root); @@ -366,6 +510,8 @@ struct corecg_test { T(test_cgcore_parent_becomes_threaded), T(test_cgcore_invalid_domain), T(test_cgcore_populated), + T(test_cgcore_proc_migration), + T(test_cgcore_thread_migration), }; #undef T -- cgit v1.2.3-59-g8ed1b