From patchwork Tue Mar 17 10:55:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229347 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FA74C18E5B for ; Tue, 17 Mar 2020 10:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78EDC20757 for ; Tue, 17 Mar 2020 10:59:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584442779; bh=PM8pvE6OwB8LDMCq4KfLYQAvcmFk6uCBwLt+Y0/b59A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rtVkqy2CCSZxapDSwzFYS2qplLu7rhmc3Rvw/uuLYA17c7cLGn1km3d1pQqf/NY57 KeFRBRPJMGx+OZTfMqbGmobZislKXqyvksia7gM6ZOnnpJLa1BXd8KCeSMSLot6o0p UQqVoaRRP0YESbHGFIkN2aYdIzdnPaZ90ZhUCGrU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727088AbgCQK7i (ORCPT ); Tue, 17 Mar 2020 06:59:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:38114 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727468AbgCQK7f (ORCPT ); Tue, 17 Mar 2020 06:59:35 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9422420658; Tue, 17 Mar 2020 10:59:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584442775; bh=PM8pvE6OwB8LDMCq4KfLYQAvcmFk6uCBwLt+Y0/b59A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2CCiXbg0BzB9iJG5/slSaTB7yquxdMErytO0BNCkmSgYM4q9MMOU5HYkWTE0DnSCp XZtPm9gNdtl55KlE93AcBbzEjiIuMH0jJ8m3HsXyB8rb9FXyxJrspczAq6RDDS5v7Z Odaeh92IiyaFe99Bjxcy/7huFko64zGknQZ6K+es= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tommi Rantala , Arnaldo Carvalho de Melo , Alexander Shishkin , Darren Hart , Davidlohr Bueso , Jiri Olsa , Mark Rutland , Namhyung Kim , Peter Zijlstra , Thomas Gleixner Subject: [PATCH 4.19 78/89] perf bench futex-wake: Restore thread count default to online CPU count Date: Tue, 17 Mar 2020 11:55:27 +0100 Message-Id: <20200317103309.069345868@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200317103259.744774526@linuxfoundation.org> References: <20200317103259.744774526@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tommi Rantala commit f649bd9dd5d5004543bbc3c50b829577b49f5d75 upstream. Since commit 3b2323c2c1c4 ("perf bench futex: Use cpumaps") the default number of threads the benchmark uses got changed from number of online CPUs to zero: $ perf bench futex wake # Running 'futex/wake' benchmark: Run summary [PID 15930]: blocking on 0 threads (at [private] futex 0x558b8ee4bfac), waking up 1 at a time. [Run 1]: Wokeup 0 of 0 threads in 0.0000 ms [...] [Run 10]: Wokeup 0 of 0 threads in 0.0000 ms Wokeup 0 of 0 threads in 0.0004 ms (+-40.82%) Restore the old behavior by grabbing the number of online CPUs via cpu->nr: $ perf bench futex wake # Running 'futex/wake' benchmark: Run summary [PID 18356]: blocking on 8 threads (at [private] futex 0xb3e62c), waking up 1 at a time. [Run 1]: Wokeup 8 of 8 threads in 0.0260 ms [...] [Run 10]: Wokeup 8 of 8 threads in 0.0270 ms Wokeup 8 of 8 threads in 0.0419 ms (+-24.35%) Fixes: 3b2323c2c1c4 ("perf bench futex: Use cpumaps") Signed-off-by: Tommi Rantala Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Darren Hart Cc: Davidlohr Bueso Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lore.kernel.org/lkml/20200305083714.9381-3-tommi.t.rantala@nokia.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/bench/futex-wake.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/tools/perf/bench/futex-wake.c +++ b/tools/perf/bench/futex-wake.c @@ -42,7 +42,7 @@ static bool done = false, silent = false static pthread_mutex_t thread_lock; static pthread_cond_t thread_parent, thread_worker; static struct stats waketime_stats, wakeup_stats; -static unsigned int ncpus, threads_starting, nthreads = 0; +static unsigned int threads_starting, nthreads = 0; static int futex_flag = 0; static const struct option options[] = { @@ -140,7 +140,7 @@ int bench_futex_wake(int argc, const cha sigaction(SIGINT, &act, NULL); if (!nthreads) - nthreads = ncpus; + nthreads = cpu->nr; worker = calloc(nthreads, sizeof(*worker)); if (!worker)