Re: [PATCH v6 0/3] perf test: Per-test timeouts and JUnit XML schema compliance

[Ian Rogers]

On Thu, Oct 22, 2026 at 3:22 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> This series adds per-test timeout support to 'perf test', improves JUnit
> XML output to validate against strict JUnit schemas, and ensures time
> spent waiting for the shared mlock budget does not count towards a
> test's timeout or reported duration:
>
> 1. Add a per-test timeout (default 120s, configurable via '-t'/'--timeout',
>    0 to disable, disabled with '-F'/'--dont-fork'). Forked tests run in
>    their own process groups and the existing polling loops in
>    finish_test() and finish_tests_parallel() check elapsed runtimes,
>    sending SIGTERM on timeout and escalating to SIGKILL after 1 second.
>    Timed out tests are reported as 'TIMEOUT!', listed in the summary,
>    and recorded as '<error message="TIMEOUT" type="timeout">' in JUnit
>    XML output.
>
> 2. Update 'perf test -j' output to validate cleanly against both the
>    Apache Ant/Windy Road JUnit schema (JUnit.xsd) and the Jenkins
>    xUnit/Maven Surefire schema (junit-10.xsd), including required
>    '<testsuite>' attributes, '<properties>' from uname, '<system-out/>'
>    and '<system-err/>', self-closing tags, apostrophe escaping, and
>    UTF-8/XML 1.0 codepoint validation.
>
> 3. Record each mlock-serialized test's start time in the shared
>    mlock_budget mapping when it acquires mlock_budget->lock in
>    run_test_case_mlocked(), so tests waiting for the mlock budget do not
>    time out while waiting in line and their reported elapsed time
>    reflects actual execution time.
>
> v6:
>  - Reap finished child tests (invoking kill_timed_out_group()) before
>    draining process.err in finish_test() and finish_tests_parallel(),
>    and skip draining in handle_child_pipe_activity() once a timed out
>    test has finished, so a noisy surviving subprocess cannot block the
>    pipe drain loop before the process group is killed.
>
> v5:
>  - Rebase onto tmp.perf-tools-next (patch 3 of v4 was applied upstream)
>    and add Namhyung's Acked-by to patches 1 and 2.
>  - Add patch 3 so tests waiting on mlock_budget->lock don't time out
>    while waiting.
>  - Increase the default per-test timeout from 60s to 120s. When running
>    the full suite as root (where CAP_IPC_LOCK lifts the mlock limit and
>    mlock_budget is unused), all ~180 non-exclusive tests start
>    simultaneously at t=0 and contend heavily on CPUs, /proc scanning,
>    and vmlinux/DWARF symbol resolution. On a 28-CPU hybrid machine, a
>    60s timeout resulted in 33 timeouts across the parallel burst and
>    large sequential suites; increasing the default to 120s allowed
>    longer tests ('kernel lock contention analysis test' at 115.3s,
>    'task-analyzer python test' at 94.7s, 'perf data type profiling
>    tests' at 92.6s, 'perf metrics value validation' at 91.2s, 'perf
>    record tests' at 79.0s, and 'python profiling with jitdump' at 62.7s)
>    to complete, reducing timeouts from 33 to 2 ('perf record LBR tests'
>    and 'perftool-testsuite_report') and overall suite wall-clock time
>    from 503.5s to 363.9s.
>
> v4:
>  - Drop the ITIMER_REAL timer and SIGALRM handler in patch 1, relying on
>    the existing 10ms/100ms polling loops in finish_test() and
>    finish_tests_parallel() to detect timeouts.
>  - Only fall back to kill(pid, sig) when kill(-pid, sig) fails, and
>    ignore SIGTERM/SIGINT while waiting for subprocesses in
>    run_test_child().
>  - Add patch 3 to avoid stack trace noise in verbose=1 failure snippets.
>
> v3:
>  - Block SIGINT/SIGTERM while a test process may be reaped and until its
>    pid is cleared, and skip already reaped tests in the signal path.
>
> v2:
>  - Reset SIGALRM to SIG_DFL in the forked test child.
>  - Replace the blocking waitpid(-1) loop with a bounded, non-blocking
>    wait that only runs when interrupted by SIGTERM/SIGINT.
>  - Ensure the SIGKILL escalation reaches the whole process group before
>    the zombie is reaped.
>  - Factor out timespec_diff_secs() and TEST_KILL_GRACE_SECS.
>
> Assisted-by: Antigravity:gemini-3.1-pro
>
> Ian Rogers (3):
>   perf test: Add per-test timeout support
>   perf test: Improve JUnit XML schema compliance and completeness
>   perf test: Don't count mlock budget wait time towards test timeout

Ping.

The sashiko reviews are clean:
https://sashiko.dev/#/patchset/20261022222245.2064964-1-irogers@xxxxxxxxxx

There's an additional patch for making the mlock waiting time not
count as timeout time:
https://lore.kernel.org/linux-perf-users/20261022222245.2064964-4-irogers@xxxxxxxxxx/
that is missing any tags.

Thanks,
Ian

>  tools/perf/Documentation/perf-test.txt |  12 +-
>  tools/perf/tests/builtin-test.c        | 662 +++++++++++++++++++------
>  tools/perf/tests/tests.h               |   7 +-
>  3 files changed, 535 insertions(+), 146 deletions(-)
>
> --
> 2.56.0.307.g5fe7bd680c-goog
>