On Thu Jul 23, 2026 at 2:13 AM EDT, Jiayuan Chen wrote: > Several CI runs failed in the libarena parallel tests with -4 (-EINTR) [1], > which says nothing about what actually went wrong. > > Two workers can fail like this: > > worker 1: gives up, e.g. the rendezvous times out, sets test_abort and > returns its own error (-ETIMEDOUT) > worker 2: sees test_abort and returns -EINTR > > -EINTR only means "someone else already gave up", so it carries no > information. Which of the two gets reported depends on the order > pthread_join() collects them, because > > err = err ?: (long)thread_ret; > > keeps the first non-zero value and drops the rest. When the -EINTR worker > comes first, the error describing the actual failure is lost. > > Skip -EINTR entirely: a worker only returns it once another worker has > already reported the real error, so report and log only the real errors. > > It is still unclear whether the timeouts come from CI load or from a > problem in the test itself. Report the error accurately first, so the next > failure can be diagnosed. > > [1]: > https://github.com/kernel-patches/bpf/actions/runs/29867905253/job/88764463566 > https://github.com/kernel-patches/bpf/actions/runs/29878191901/job/88794845824 > > Signed-off-by: Jiayuan Chen <[email protected]>
Reviewed-by: Emil Tsalapatis <[email protected]> > > --- > v1 -> v2: > - hoist the worker_err declaration to the top of the function > - skip -EINTR workers entirely: do not aggregate and do not log them > - comment/commit message wording fixes > > v1: > https://lore.kernel.org/bpf/[email protected]/ > --- > .../selftests/bpf/prog_tests/libarena.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/libarena.c > b/tools/testing/selftests/bpf/prog_tests/libarena.c > index df7e4b8dc394..daade4150af6 100644 > --- a/tools/testing/selftests/bpf/prog_tests/libarena.c > +++ b/tools/testing/selftests/bpf/prog_tests/libarena.c > @@ -73,6 +73,7 @@ static int run_libarena_parallel_test_workers(struct > libarena *skel, > uint32_t nthreads; > void *thread_ret; > int ret, err = 0; > + int worker_err; > int i; > > for (nthreads = 0; nthreads < UINT_MAX; nthreads++) { > @@ -118,7 +119,22 @@ static int run_libarena_parallel_test_workers(struct > libarena *skel, > continue; > } > > - err = err ?: (long)thread_ret; > + worker_err = (long)thread_ret; > + > + /* > + * A worker that bails out because another one already gave up > + * reports -EINTR. It is collateral damage that carries no > + * information, so skip it entirely: never let it become the > + * reported error, and don't log it either. > + */ > + if (!worker_err || worker_err == -EINTR) > + continue; > + > + if (!err) > + err = worker_err; > + > + fprintf(stdout, "%.*s__%d returned %d\n", (int)prefixlen, name, > + i, worker_err); > } > > free(threads);
