Test cgroup v2 freezer time stat. Freezer time accounting should be independent of other cgroups in the hierarchy and should increase iff a cgroup is CGRP_FREEZE (regardless of whether it reaches CGRP_FROZEN).
Skip these tests on systems without freeze time accounting.
Signed-off-by: Tiffany Yang ynaffit@google.com Cc: Michal Koutný mkoutny@suse.com --- v3 -> v4: * Clean up logic around skipping selftests and decrease granularity of sleep times, as suggested by Michal. --- tools/testing/selftests/cgroup/test_freezer.c | 663 ++++++++++++++++++ 1 file changed, 663 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_freezer.c b/tools/testing/selftests/cgroup/test_freezer.c index 8730645d363a..dfb763819581 100644 --- a/tools/testing/selftests/cgroup/test_freezer.c +++ b/tools/testing/selftests/cgroup/test_freezer.c @@ -804,6 +804,662 @@ static int test_cgfreezer_vfork(const char *root) return ret; }
+/* + * Get the current frozen_usec for the cgroup. + */ +static long cg_check_freezetime(const char *cgroup) +{ + return cg_read_key_long(cgroup, "cgroup.stat.local", + "frozen_usec "); +} + +/* + * Test that the freeze time will behave as expected for an empty cgroup. + */ +static int test_cgfreezer_time_empty(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup = NULL; + long prev, curr; + + cgroup = cg_name(root, "cg_time_test_empty"); + if (!cgroup) + goto cleanup; + + /* + * 1) Create an empty cgroup and check that its freeze time + * is 0. + */ + if (cg_create(cgroup)) + goto cleanup; + + curr = cg_check_freezetime(cgroup); + if (curr < 0) { + ret = KSFT_SKIP; + goto cleanup; + } + if (curr > 0) { + debug("Expect time (%ld) to be 0\n", curr); + goto cleanup; + } + + if (cg_freeze_nowait(cgroup, true)) + goto cleanup; + + /* + * 2) Sleep for 1000 us. Check that the freeze time is at + * least 1000 us. + */ + usleep(1000); + curr = cg_check_freezetime(cgroup); + if (curr < 1000) { + debug("Expect time (%ld) to be at least 1000 us\n", + curr); + goto cleanup; + } + + /* + * 3) Unfreeze the cgroup. Check that the freeze time is + * larger than at 2). + */ + if (cg_freeze_nowait(cgroup, false)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr <= prev) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + /* + * 4) Check the freeze time again to ensure that it has not + * changed. + */ + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr != prev) { + debug("Expect time (%ld) to be unchanged from previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +/* + * A simple test for cgroup freezer time accounting. This test follows + * the same flow as test_cgfreezer_time_empty, but with a single process + * in the cgroup. + */ +static int test_cgfreezer_time_simple(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup = NULL; + long prev, curr; + + cgroup = cg_name(root, "cg_time_test_simple"); + if (!cgroup) + goto cleanup; + + /* + * 1) Create a cgroup and check that its freeze time is 0. + */ + if (cg_create(cgroup)) + goto cleanup; + + curr = cg_check_freezetime(cgroup); + if (curr < 0) { + ret = KSFT_SKIP; + goto cleanup; + } + if (curr > 0) { + debug("Expect time (%ld) to be 0\n", curr); + goto cleanup; + } + + /* + * 2) Populate the cgroup with one child and check that the + * freeze time is still 0. + */ + cg_run_nowait(cgroup, child_fn, NULL); + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr > prev) { + debug("Expect time (%ld) to be 0\n", curr); + goto cleanup; + } + + if (cg_freeze_nowait(cgroup, true)) + goto cleanup; + + /* + * 3) Sleep for 1000 us. Check that the freeze time is at + * least 1000 us. + */ + usleep(1000); + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr < 1000) { + debug("Expect time (%ld) to be at least 1000 us\n", + curr); + goto cleanup; + } + + /* + * 4) Unfreeze the cgroup. Check that the freeze time is + * larger than at 3). + */ + if (cg_freeze_nowait(cgroup, false)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr <= prev) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + /* + * 5) Sleep for 1000 us. Check that the freeze time is the + * same as at 4). + */ + usleep(1000); + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr != prev) { + debug("Expect time (%ld) to be unchanged from previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +/* + * Test that freezer time accounting works as expected, even while we're + * populating a cgroup with processes. + */ +static int test_cgfreezer_time_populate(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup = NULL; + long prev, curr; + int i; + + cgroup = cg_name(root, "cg_time_test_populate"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + curr = cg_check_freezetime(cgroup); + if (curr < 0) { + ret = KSFT_SKIP; + goto cleanup; + } + if (curr > 0) { + debug("Expect time (%ld) to be 0\n", curr); + goto cleanup; + } + + /* + * 1) Populate the cgroup with 100 processes. Check that + * the freeze time is 0. + */ + for (i = 0; i < 100; i++) + cg_run_nowait(cgroup, child_fn, NULL); + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr != prev) { + debug("Expect time (%ld) to be 0\n", curr); + goto cleanup; + } + + /* + * 2) Wait for the group to become fully populated. Check + * that the freeze time is 0. + */ + if (cg_wait_for_proc_count(cgroup, 100)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr != prev) { + debug("Expect time (%ld) to be 0\n", curr); + goto cleanup; + } + + /* + * 3) Freeze the cgroup and then populate it with 100 more + * processes. Check that the freeze time continues to grow. + */ + if (cg_freeze_nowait(cgroup, true)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr <= prev) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + for (i = 0; i < 100; i++) + cg_run_nowait(cgroup, child_fn, NULL); + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr <= prev) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + /* + * 4) Wait for the group to become fully populated. Check + * that the freeze time is larger than at 3). + */ + if (cg_wait_for_proc_count(cgroup, 200)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr <= prev) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + /* + * 5) Unfreeze the cgroup. Check that the freeze time is + * larger than at 4). + */ + if (cg_freeze_nowait(cgroup, false)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr <= prev) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + /* + * 6) Kill the processes. Check that the freeze time is the + * same as it was at 5). + */ + if (cg_killall(cgroup)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr != prev) { + debug("Expect time (%ld) to be unchanged from previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + /* + * 7) Freeze and unfreeze the cgroup. Check that the freeze + * time is larger than it was at 6). + */ + if (cg_freeze_nowait(cgroup, true)) + goto cleanup; + if (cg_freeze_nowait(cgroup, false)) + goto cleanup; + prev = curr; + curr = cg_check_freezetime(cgroup); + if (curr <= prev) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr, prev); + goto cleanup; + } + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +/* + * Test that frozen time for a cgroup continues to work as expected, + * even as processes are migrated. Frozen cgroup A's freeze time should + * continue to increase and running cgroup B's should stay 0. + */ +static int test_cgfreezer_time_migrate(const char *root) +{ + long prev_A, curr_A, curr_B; + char *cgroup[2] = {0}; + int ret = KSFT_FAIL; + int pid; + + cgroup[0] = cg_name(root, "cg_time_test_migrate_A"); + if (!cgroup[0]) + goto cleanup; + + cgroup[1] = cg_name(root, "cg_time_test_migrate_B"); + if (!cgroup[1]) + goto cleanup; + + if (cg_create(cgroup[0])) + goto cleanup; + + if (cg_check_freezetime(cgroup[0]) < 0) { + ret = KSFT_SKIP; + goto cleanup; + } + + if (cg_create(cgroup[1])) + goto cleanup; + + pid = cg_run_nowait(cgroup[0], child_fn, NULL); + if (pid < 0) + goto cleanup; + + if (cg_wait_for_proc_count(cgroup[0], 1)) + goto cleanup; + + curr_A = cg_check_freezetime(cgroup[0]); + if (curr_A) { + debug("Expect time (%ld) to be 0\n", curr_A); + goto cleanup; + } + curr_B = cg_check_freezetime(cgroup[1]); + if (curr_B) { + debug("Expect time (%ld) to be 0\n", curr_B); + goto cleanup; + } + + /* + * Freeze cgroup A. + */ + if (cg_freeze_wait(cgroup[0], true)) + goto cleanup; + prev_A = curr_A; + curr_A = cg_check_freezetime(cgroup[0]); + if (curr_A <= prev_A) { + debug("Expect time (%ld) to be > 0\n", curr_A); + goto cleanup; + } + + /* + * Migrate from A (frozen) to B (running). + */ + if (cg_enter(cgroup[1], pid)) + goto cleanup; + + usleep(1000); + curr_B = cg_check_freezetime(cgroup[1]); + if (curr_B) { + debug("Expect time (%ld) to be 0\n", curr_B); + goto cleanup; + } + + prev_A = curr_A; + curr_A = cg_check_freezetime(cgroup[0]); + if (curr_A <= prev_A) { + debug("Expect time (%ld) to be more than previous check (%ld)\n", + curr_A, prev_A); + goto cleanup; + } + + ret = KSFT_PASS; + +cleanup: + if (cgroup[0]) + cg_destroy(cgroup[0]); + free(cgroup[0]); + if (cgroup[1]) + cg_destroy(cgroup[1]); + free(cgroup[1]); + return ret; +} + +/* + * The test creates a cgroup and freezes it. Then it creates a child cgroup. + * After that it checks that the child cgroup has a non-zero freeze time + * that is less than the parent's. Next, it freezes the child, unfreezes + * the parent, and sleeps. Finally, it checks that the child's freeze + * time has grown larger than the parent's. + */ +static int test_cgfreezer_time_parent(const char *root) +{ + char *parent, *child = NULL; + int ret = KSFT_FAIL; + long ptime, ctime; + + parent = cg_name(root, "cg_test_parent_A"); + if (!parent) + goto cleanup; + + child = cg_name(parent, "cg_test_parent_B"); + if (!child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_check_freezetime(parent) < 0) { + ret = KSFT_SKIP; + goto cleanup; + } + + if (cg_freeze_wait(parent, true)) + goto cleanup; + + usleep(1000); + if (cg_create(child)) + goto cleanup; + + if (cg_check_frozen(child, true)) + goto cleanup; + + /* + * Since the parent was frozen the entire time the child cgroup + * was being created, we expect the parent's freeze time to be + * larger than the child's. + * + * Ideally, we would be able to check both times simultaneously, + * but here we get the child's after we get the parent's. + */ + ptime = cg_check_freezetime(parent); + ctime = cg_check_freezetime(child); + if (ptime <= ctime) { + debug("Expect ptime (%ld) > ctime (%ld)\n", ptime, ctime); + goto cleanup; + } + + if (cg_freeze_nowait(child, true)) + goto cleanup; + + if (cg_freeze_wait(parent, false)) + goto cleanup; + + if (cg_check_frozen(child, true)) + goto cleanup; + + usleep(100000); + + ctime = cg_check_freezetime(child); + ptime = cg_check_freezetime(parent); + + if (ctime <= ptime) { + debug("Expect ctime (%ld) > ptime (%ld)\n", ctime, ptime); + goto cleanup; + } + + ret = KSFT_PASS; + +cleanup: + if (child) + cg_destroy(child); + free(child); + if (parent) + cg_destroy(parent); + free(parent); + return ret; +} + +/* + * The test creates a parent cgroup and a child cgroup. Then, it freezes + * the child and checks that the child's freeze time is greater than the + * parent's, which should be zero. + */ +static int test_cgfreezer_time_child(const char *root) +{ + char *parent, *child = NULL; + int ret = KSFT_FAIL; + long ptime, ctime; + + parent = cg_name(root, "cg_test_child_A"); + if (!parent) + goto cleanup; + + child = cg_name(parent, "cg_test_child_B"); + if (!child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_check_freezetime(parent) < 0) { + ret = KSFT_SKIP; + goto cleanup; + } + + if (cg_create(child)) + goto cleanup; + + if (cg_freeze_wait(child, true)) + goto cleanup; + + ctime = cg_check_freezetime(child); + ptime = cg_check_freezetime(parent); + if (ptime != 0) { + debug("Expect ptime (%ld) to be 0\n", ptime); + goto cleanup; + } + + if (ctime <= ptime) { + debug("Expect ctime (%ld) <= ptime (%ld)\n", ctime, ptime); + goto cleanup; + } + + ret = KSFT_PASS; + +cleanup: + if (child) + cg_destroy(child); + free(child); + if (parent) + cg_destroy(parent); + free(parent); + return ret; +} + +/* + * The test creates the following hierarchy: + * A + * | + * B + * | + * C + * + * Then it freezes the cgroups in the order C, B, A. + * Then it unfreezes the cgroups in the order A, B, C. + * Then it checks that C's freeze time is larger than B's and + * that B's is larger than A's. + */ +static int test_cgfreezer_time_nested(const char *root) +{ + char *cgroup[3] = {0}; + int ret = KSFT_FAIL; + long time[3] = {0}; + int i; + + cgroup[0] = cg_name(root, "cg_test_time_A"); + if (!cgroup[0]) + goto cleanup; + + cgroup[1] = cg_name(cgroup[0], "B"); + if (!cgroup[1]) + goto cleanup; + + cgroup[2] = cg_name(cgroup[1], "C"); + if (!cgroup[2]) + goto cleanup; + + if (cg_create(cgroup[0])) + goto cleanup; + + if (cg_check_freezetime(cgroup[0]) < 0) { + ret = KSFT_SKIP; + goto cleanup; + } + + if (cg_create(cgroup[1])) + goto cleanup; + + if (cg_create(cgroup[2])) + goto cleanup; + + if (cg_freeze_nowait(cgroup[2], true)) + goto cleanup; + + if (cg_freeze_nowait(cgroup[1], true)) + goto cleanup; + + if (cg_freeze_nowait(cgroup[0], true)) + goto cleanup; + + usleep(1000); + + if (cg_freeze_nowait(cgroup[0], false)) + goto cleanup; + + if (cg_freeze_nowait(cgroup[1], false)) + goto cleanup; + + if (cg_freeze_nowait(cgroup[2], false)) + goto cleanup; + + time[2] = cg_check_freezetime(cgroup[2]); + time[1] = cg_check_freezetime(cgroup[1]); + time[0] = cg_check_freezetime(cgroup[0]); + + if (time[2] <= time[1]) { + debug("Expect C's time (%ld) > B's time (%ld)", time[2], time[1]); + goto cleanup; + } + + if (time[1] <= time[0]) { + debug("Expect B's time (%ld) > A's time (%ld)", time[1], time[0]); + goto cleanup; + } + + ret = KSFT_PASS; + +cleanup: + for (i = 2; i >= 0 && cgroup[i]; i--) { + cg_destroy(cgroup[i]); + free(cgroup[i]); + } + + return ret; +} + #define T(x) { x, #x } struct cgfreezer_test { int (*fn)(const char *root); @@ -819,6 +1475,13 @@ struct cgfreezer_test { T(test_cgfreezer_stopped), T(test_cgfreezer_ptraced), T(test_cgfreezer_vfork), + T(test_cgfreezer_time_empty), + T(test_cgfreezer_time_simple), + T(test_cgfreezer_time_populate), + T(test_cgfreezer_time_migrate), + T(test_cgfreezer_time_parent), + T(test_cgfreezer_time_child), + T(test_cgfreezer_time_nested), }; #undef T