Re: [PATCH v3 1/2] perf test: Add per-test timeout support

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Sep 28, 2026 at 07:53:44PM -0700, Ian Rogers wrote:
> When a test hangs in 'perf test', the entire test run hangs and makes it
> difficult to inspect output from other tests.
> 
> Add a new TEST_TIMEOUT result category and a per-test timeout (default
> 60 seconds, configurable via '-t'/'--timeout', with 0 to disable). When
> '-F' ('--dont-fork') is specified, timeouts are disabled.
> 
> To enforce the timeout:
> - Place each forked test child into its own process group via
>   setpgid(0, 0) in the child and setpgid(pid, pid) in the parent so any
>   subprocesses spawned by shell or workload tests can be terminated
>   together.
> - Arm an ITIMER_REAL periodic timer with a SIGALRM handler (using
>   SA_RESTART so /proc status reads in check_if_command_finished() are
>   not interrupted by EINTR while poll()/usleep() waits still wake up).

Do we really need this timer?  I think poll() already has a timeout so
it'll wake up on every 100 msec anyway?

Thanks,
Namhyung


> - Check elapsed child runtimes against test_timeout in finish_test() and
>   finish_tests_parallel(), sending SIGTERM first and escalating to
>   SIGKILL after 1 second if the child process group has not exited.
> - Report timed out tests in red ('TIMEOUT!'), track and display them in
>   the test summary, and emit '<error message="TIMEOUT" type="timeout">'
>   counted under the 'errors' attribute in JUnit XML output.
> - Document '-t'/'--timeout' and '-F'/'--dont-fork' in perf-test.txt.
> 
> Assisted-by: Antigravity:gemini-3.1-pro
> Signed-off-by: Ian Rogers <irogers@google.com>