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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7DDFC4332F for ; Wed, 13 Dec 2023 13:04:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379136AbjLMNEu (ORCPT ); Wed, 13 Dec 2023 08:04:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36762 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379206AbjLMNEn (ORCPT ); Wed, 13 Dec 2023 08:04:43 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DCAC9121 for ; Wed, 13 Dec 2023 04:54:54 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D1C24C433C7; Wed, 13 Dec 2023 12:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702472094; bh=gBG7q7d6yeZOd/c1kwWuK1qPKa2vW1p2OK1rECWWvTI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TPj3sNYbXok2E+B31zh2s3H/L6aacMNCDhzhZ71Mv0L0tL9xoHx0BF8RiDWrUDX03 hlY8FULjAeL+T2oGzyMKlDT4jev8KnS9u6o7reCF2OrDJ43yCpPhC7AafRLQPKDCyD 6MV6gOMSt+rrcsaLqALumG+QCDlD5QzvmVpCPS4yXxSfg9PAdCwq/HPtjgrUHO24ya NQ48QfEcUntf7KUcpAlpQauJ8OSmkD0AjD8iv8RR6jw9DQV6sXgIfIXVOhSEQuHkTr exSG4xLITkcmc3yddRyStj0rvF/Z2uD+l957iveD/Y1P9leZv0ZKvmfUHGtiP/8SV9 flZoF06HLS96A== Date: Wed, 13 Dec 2023 21:54:50 +0900 From: Masami Hiramatsu (Google) To: Naveen N Rao Cc: , , Steven Rostedt , Masami Hiramatsu , Shuah Khan , Michael Ellerman Subject: Re: [PATCH v2] selftests/ftrace: Add test to exercize function tracer across cpu hotplug Message-Id: <20231213215450.792f5e6f21eb3e709f4ea05c@kernel.org> In-Reply-To: <20231213113802.1278600-1-naveen@kernel.org> References: <20231213113802.1278600-1-naveen@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 13 Dec 2023 17:08:02 +0530 Naveen N Rao wrote: > Add a test to exercize cpu hotplug with the function tracer active to > ensure that sensitive functions in idle path are excluded from being > traced. This helps catch issues such as the one fixed by commit > 4b3338aaa74d ("powerpc/ftrace: Fix stack teardown in ftrace_no_trace"). > Looks good to me. Acked-by: Masami Hiramatsu (Google) Thank you, > Signed-off-by: Naveen N Rao > --- > v2: Add a check for next available online cpu, as suggested by Masami. > > .../ftrace/test.d/ftrace/func_hotplug.tc | 42 +++++++++++++++++++ > 1 file changed, 42 insertions(+) > create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc > > diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc > new file mode 100644 > index 000000000000..ccfbfde3d942 > --- /dev/null > +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc > @@ -0,0 +1,42 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0-or-later > +# description: ftrace - function trace across cpu hotplug > +# requires: function:tracer > + > +if ! which nproc ; then > + nproc() { > + ls -d /sys/devices/system/cpu/cpu[0-9]* | wc -l > + } > +fi > + > +NP=`nproc` > + > +if [ $NP -eq 1 ] ;then > + echo "We cannot test cpu hotplug in UP environment" > + exit_unresolved > +fi > + > +# Find online cpu > +for i in /sys/devices/system/cpu/cpu[1-9]*; do > + if [ -f $i/online ] && [ "$(cat $i/online)" = "1" ]; then > + cpu=$i > + break > + fi > +done > + > +if [ -z "$cpu" ]; then > + echo "We cannot test cpu hotplug with a single cpu online" > + exit_unresolved > +fi > + > +echo 0 > tracing_on > +echo > trace > + > +: "Set $(basename $cpu) offline/online with function tracer enabled" > +echo function > current_tracer > +echo 1 > tracing_on > +(echo 0 > $cpu/online) > +(echo "forked"; sleep 1) > +(echo 1 > $cpu/online) > +echo 0 > tracing_on > +echo nop > current_tracer > > base-commit: b85ea95d086471afb4ad062012a4d73cd328fa86 > -- > 2.43.0 > -- Masami Hiramatsu (Google)