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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED 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 80DE8C433F4 for ; Sat, 25 Aug 2018 01:45:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25C3920779 for ; Sat, 25 Aug 2018 01:45:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="UaGbgPch" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25C3920779 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726879AbeHYFWT (ORCPT ); Sat, 25 Aug 2018 01:22:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:56480 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725958AbeHYFWT (ORCPT ); Sat, 25 Aug 2018 01:22:19 -0400 Received: from devbox (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 B196521581; Sat, 25 Aug 2018 01:45:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1535161511; bh=kn3pRfgh4JU1kz7qtU1d8Ho0FwFhoDcYBJSvOmQzv5g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=UaGbgPchXJBAKdLgr+r9oNDpWFzj8QXGuPtWyPYmF+AdI3U/m5qqRRrKjtcHwHSKI C9eRqKr80gmW5/Y0WB893WqpvSYjfCqWZQWhoetBy85E2Z4xxwAIOfHDX1A3/uetbm pgjGSp+h3EXhMrW/MSfFhkydigf1sAb8HEIwLUvs= Date: Sat, 25 Aug 2018 10:45:09 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: Shuah Khan , Ingo Molnar , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 24/32] selftests/ftrace: Add max stack tracer testcase Message-Id: <20180825104509.1b739d5d17d860e453daa0ca@kernel.org> In-Reply-To: <20180824192352.262144f5@gandalf.local.home> References: <153443695002.23257.13628220023468200991.stgit@devbox> <153443763074.23257.4052504725796725062.stgit@devbox> <20180824192352.262144f5@gandalf.local.home> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 24 Aug 2018 19:23:52 -0400 Steven Rostedt wrote: > On Fri, 17 Aug 2018 01:40:30 +0900 > Masami Hiramatsu wrote: > > > Add a testcase for max stack tracer, which checks basic > > max stack usage tracing and its filter feature. > > > > Signed-off-by: Masami Hiramatsu > > --- > > .../ftrace/test.d/ftrace/func_stack_tracer.tc | 39 ++++++++++++++++++++ > > 1 file changed, 39 insertions(+) > > create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > > > diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > new file mode 100644 > > index 000000000000..b414f0e3c646 > > --- /dev/null > > +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_stack_tracer.tc > > @@ -0,0 +1,39 @@ > > +#!/bin/sh > > +# SPDX-License-Identifier: GPL-2.0 > > +# description: ftrace - Max stack tracer > > +# Test the basic function of max-stack usage tracing > > + > > +if [ ! -f stack_trace ]; then > > + echo "Max stack tracer is not supported - please make CONFIG_STACK_TRACER=y" > > + exit_unsupported > > +fi > > + > > +echo > stack_trace_filter > > +echo 0 > stack_max_size > > +echo 1 > /proc/sys/kernel/stack_tracer_enabled > > + > > +: "Fork and wait for the first entry become !lock" > > +timeout=10 > > +while [ $timeout -ne 0 ]; do > > + ( echo "forked" ) > > + FL=`grep " 0)" stack_trace` > > + echo $FL | grep -q "lock" || break; > > + timeout=$((timeout - 1)) > > +done > > +echo 0 > /proc/sys/kernel/stack_tracer_enabled > > + > > +echo '*lock*' > stack_trace_filter > > +test `cat stack_trace_filter | wc -l` -eq `grep lock stack_trace_filter | wc -l` > > + > > +echo 0 > stack_max_size > > +echo 1 > /proc/sys/kernel/stack_tracer_enabled > > This test fails quite a bit because it doesn't guarantee that another > stack trace gets in that is bigger, and we don't find the "lock". Hmm, maybe I misunderstand what is the stack_trace_filter. I thought it filtered the function that triggered stack trace, so the top of stack trace was always filtered function. If not, what does this filter? Thank you, > > -- Steve > > > + > > +: "Fork and always the first entry including lock" > > +timeout=10 > > +while [ $timeout -ne 0 ]; do > > + ( echo "forked" ) > > + FL=`grep " 0)" stack_trace` > > + echo $FL | grep -q "lock" > > + timeout=$((timeout - 1)) > > +done > > +echo 0 > /proc/sys/kernel/stack_tracer_enabled > -- Masami Hiramatsu