From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 7FF97C2D0BF for ; Tue, 10 Dec 2019 03:42:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 523B224656 for ; Tue, 10 Dec 2019 03:42:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575949350; bh=O8zSgVKAg5FjaVRPXFRAgSlpaYk/7KotlPxmPGoBjpI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EWCFpRkCY3K+UUurPwfPx/3M78DvM46N5G1WIBfGDQ68wjAcxR16cuYqjQwEhJJVi DZAN1yOHFwTmiAs5zUfzmqKPCDrU+TsaiB48s7WmXBCAwI8oPnNegPrMP+j2zBU0br 98ChUf/O22EFU1bIsc0Sv3R3312cq4etBuk20zH8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726974AbfLJDm3 (ORCPT ); Mon, 9 Dec 2019 22:42:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:32832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727181AbfLJDm3 (ORCPT ); Mon, 9 Dec 2019 22:42:29 -0500 Received: from paulmck-ThinkPad-P72.home (199-192-87-166.static.wiline.com [199.192.87.166]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C5BF9222C4; Tue, 10 Dec 2019 03:42:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575949348; bh=O8zSgVKAg5FjaVRPXFRAgSlpaYk/7KotlPxmPGoBjpI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xIAsa6lJroSRwfUyaYatY1AIbzHZRRUDhGm0/tEZFSHLsBEPDuMVXSUGV6oX4BrWy rle21P0MNI49Il0Kkxb/HBFjLcdXe0tuxniloaWr4dJso6SvMeVmHZLIq2yZCJuE+P FuQYemvdvRpQ1jeLC5zesB/0wpZAbfk+8LFdZsOw= From: paulmck@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 12/12] torture: Hoist calls to lscpu to higher-level kvm.sh script Date: Mon, 9 Dec 2019 19:42:17 -0800 Message-Id: <20191210034217.405-12-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20191210034119.GA32711@paulmck-ThinkPad-P72> References: <20191210034119.GA32711@paulmck-ThinkPad-P72> Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: "Paul E. McKenney" On some kernels, concurrent calls to the lscpu command result in severe slowdowns. For example, on v4.16, a single lscpu invocation takes about two milliseconds, four concurrent invocations more than two seconds, and 16 concurrent invocations more than 20 seconds. Given that the only goal is to learn the number of CPUs, invoking lscpu but once suffices. This commit therefore invokes lscpu early in kvm.sh execution, setting the initial value of the TORTURE_ALLOTED_CPUS environment variable. Signed-off-by: Paul E. McKenney --- tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh | 7 +++---- tools/testing/selftests/rcutorture/bin/kvm.sh | 11 ++++++++--- 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh index 1d98992..e035230 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh @@ -133,11 +133,10 @@ fi qemu_args="-enable-kvm -nographic $qemu_args" cpu_count=`configNR_CPUS.sh $resdir/ConfigFragment` cpu_count=`configfrag_boot_cpus "$boot_args" "$config_template" "$cpu_count"` -vcpus=`identify_qemu_vcpus` -if test $cpu_count -gt $vcpus +if test "$cpu_count" -gt "$TORTURE_ALLOTED_CPUS" then - echo CPU count limited from $cpu_count to $vcpus | tee -a $resdir/Warnings - cpu_count=$vcpus + echo CPU count limited from $cpu_count to $TORTURE_ALLOTED_CPUS | tee -a $resdir/Warnings + cpu_count=$TORTURE_ALLOTED_CPUS fi qemu_args="`specify_qemu_cpus "$QEMU" "$qemu_args" "$cpu_count"`" diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh index e19151c..78d18ab 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm.sh @@ -24,7 +24,9 @@ dur=$((30*60)) dryrun="" KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM PATH=${KVM}/bin:$PATH; export PATH -TORTURE_ALLOTED_CPUS="" +. functions.sh + +TORTURE_ALLOTED_CPUS="`identify_qemu_vcpus`" TORTURE_DEFCONFIG=defconfig TORTURE_BOOT_IMAGE="" TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD @@ -40,8 +42,6 @@ cpus=0 ds=`date +%Y.%m.%d-%H:%M:%S` jitter="-1" -. functions.sh - usage () { echo "Usage: $scriptname optional arguments:" echo " --bootargs kernel-boot-arguments" @@ -93,6 +93,11 @@ do checkarg --cpus "(number)" "$#" "$2" '^[0-9]*$' '^--' cpus=$2 TORTURE_ALLOTED_CPUS="$2" + max_cpus="`identify_qemu_vcpus`" + if test "$TORTURE_ALLOTED_CPUS" -gt "$max_cpus" + then + TORTURE_ALLOTED_CPUS=$max_cpus + fi shift ;; --datestamp) -- 2.9.5