Re: [PATCH] selftests/cgroup: Fix intermittent test_cgfreezer_ptrace test failures
Tejun Heo <[email protected]>
| Newsgroups | org.kernel.vger.cgroups,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest |
|---|---|
| Message-ID | <[email protected]> |
Hello, Waiman. > + usleep(1000); > if (cg_check_frozen(cgroup, true)) > goto cleanup; A fixed 1ms sleep only hides the race. On a loaded machine or a slow arch (you mention ppc64) the refreeze can take longer than 1ms, and the test reads the unfrozen state and fails anyway. The freezer test already has a way to wait for this properly. cg_prepare_for_wait() sets up an inotify watch on cgroup.events and cg_wait_for() blocks until it changes. cg_enter_and_wait_for_frozen() shows the pattern: loop cg_wait_for() then cg_check_frozen(). The cgroup always ends up frozen, so looping until cg_check_frozen() reports frozen is reliable and doesn't depend on timing. Can you respin using that instead of usleep()? Also, temporaily -> temporarily, in both the changelog and the comment. Thanks. -- tejun