From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C25132B99B; Tue, 28 Oct 2025 20:37:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761683835; cv=none; b=KCTRdXDtGLzGPa6/pZ7Q1OXP4bhoWXsvHA932s40ZsjS4AXPl0WWuRvLSxs9+ut8ZYVashjMl14Goh49HlDSKkDFZ3pmd2At0boEGNNUvPZFtIPI+933yrv/iEaStAPXItWre5bYVf5HJ3B1rhoCb2gBf02O/5Y8rR74ZxJbVgU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761683835; c=relaxed/simple; bh=X+6GU/BChhinqh72N81kiyBwcfgHtagVGJha8LiJPIc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=g4hAkPNfxcPNYG7xzngZfFb+BnMuiFygUHa7BII8db9C9ukj44gFuA/bXRuKxgGd3ySTMhtD0Pwt5fkJqoBGGXrXvkpyF55Oy6tizZrr9ss43KG64A+ZDUDAmjuahaeRaxPgI/Y7V325jZwVt2/gv7uw6HNieexJ+7InLoo2YQw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YYtRk03G; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YYtRk03G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25A03C4CEFF; Tue, 28 Oct 2025 20:37:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761683834; bh=X+6GU/BChhinqh72N81kiyBwcfgHtagVGJha8LiJPIc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YYtRk03GQ0ObjH7uaQZSmGQ/bIcs2EKdx3Vco5ZFaqLRcUzZMrP4AjZBmuEYu/iOr c4Al02kVstJpDUEmLLbewZkiLKq8faHbKNgBC/HOyCNkZ/GBcieS8tXEQm7l+7VRtL FgQm0GcafRdVf0o2lS8UtA1D9DXhppisCTFQZLMTcVjz3JoBjtKnk3QiESB/fNtula pibQ/f5FarCmAebLwPgDMOgizHvZAIQZrA8EVQA8ZQ5N0489/09z0IRIFJy4nzsknC eKrWo10VsT9DN3TUDd5XDQ6dmD9yecLWUPwHvVnYUX2lNYidEw6VoPp0ltpey4IxqM cSmSMSydWUzDA== Date: Tue, 28 Oct 2025 17:37:10 -0300 From: Arnaldo Carvalho de Melo To: Ian Rogers Cc: Peter Zijlstra , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Jiri Olsa , Adrian Hunter , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] perf test workload: Add thread count argument to thloop Message-ID: References: <20251028153821.4003666-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Oct 28, 2025 at 12:55:56PM -0700, Ian Rogers wrote: > On Tue, Oct 28, 2025 at 12:13 PM Arnaldo Carvalho de Melo > wrote: > > > > On Tue, Oct 28, 2025 at 08:38:20AM -0700, Ian Rogers wrote: > > > Allow the number of threads for the thloop workload to be increased > > > beyond the normal 2. Add error checking to the parsed time and thread > > > count values. > > > > > > Signed-off-by: Ian Rogers > > > --- > > > v2: Perform the pthread_join unconditionally and ensure started > > > threads terminate. > > > --- > > > tools/perf/tests/workloads/thloop.c | 45 ++++++++++++++++++++++++----- > > > 1 file changed, 38 insertions(+), 7 deletions(-) > > > > > > diff --git a/tools/perf/tests/workloads/thloop.c b/tools/perf/tests/workloads/thloop.c > > > index 457b29f91c3e..bd8168f883fb 100644 > > > --- a/tools/perf/tests/workloads/thloop.c > > > +++ b/tools/perf/tests/workloads/thloop.c > > > @@ -31,21 +31,52 @@ static void *thfunc(void *arg) > > > > > > static int thloop(int argc, const char **argv) > > > { > > > - int sec = 1; > > > - pthread_t th; > > > + int nt = 2, sec = 1, err = 1; > > > + pthread_t *thread_list = NULL; > > > > > > if (argc > 0) > > > sec = atoi(argv[0]); > > > > > > + if (sec <= 0) { > > > + fprintf(stderr, "Error: seconds (%d) must be >= 1\n", sec); > > > + return 1; > > > + } > > > + > > > + if (argc > 1) > > > + nt = atoi(argv[1]); > > > + > > > + if (nt <= 0) { > > > + fprintf(stderr, "Error: thread count (%d) must be >= 1\n", nt); > > > + return 1; > > > + } > > > + > > > signal(SIGINT, sighandler); > > > signal(SIGALRM, sighandler); > > > - alarm(sec); > > > > > > - pthread_create(&th, NULL, thfunc, test_loop); > > > - test_loop(); > > > - pthread_join(th, NULL); > > > + thread_list = calloc(nt, sizeof(pthread_t)); > > > + if (thread_list == NULL) { > > > + fprintf(stderr, "Error: malloc failed for %d threads\n", nt); > > > + goto out; > > > + } > > > + for (int i = 1; i < nt; i++) { > > > > Why do you start at 1? What goes in thread[0]? calloc() leaves it at > > NULL, then if you have two threads you'll allocate thread[1], i gets > > incremented, 2 < 2 fails, you get just one thread created, when two were > > asked? > > > > Oh, I see, you use the main thread to run, that test_loop() just before > > the err = 0, its just that you allocate thread[0] for nothing, that > > confused me. > > Agreed. It was so I could avoid doing "nt-1" as I mentioned before. > Fwiw, pthread_self will sometimes return 0 for the main thread and so > it isn't entirely inconsistent to do things this way. Not that the > main thread should try to do a pthread_join with itself. :-) Its just a test, Acked-by: Arnaldo Carvalho de Melo > Thanks, > Ian > > > - Arnaldo > > > > > + int ret = pthread_create(&thread_list[i], NULL, thfunc, test_loop); > > > > > > - return 0; > > > + if (ret) { > > > + fprintf(stderr, "Error: failed to create thread %d\n", i); > > > + done = 1; // Ensure started threads terminate. > > > + goto out; > > > + } > > > + } > > > + alarm(sec); > > > + test_loop(); > > > + err = 0; > > > +out: > > > + for (int i = 1; i < nt; i++) { > > > + if (thread_list && thread_list[i]) > > > + pthread_join(thread_list[i], /*retval=*/NULL); > > > + } > > > + free(thread_list); > > > + return err; > > > } > > > > > > DEFINE_WORKLOAD(thloop); > > > -- > > > 2.51.1.851.g4ebd6896fd-goog