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 EE1BF4F1E0; Mon, 12 Feb 2024 23:11:20 +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=1707779481; cv=none; b=LpL/gXp6MNJ8MofNeIE4+7RFTlqso/RBwubn9fwIVGhAZu1dwkzDm+LlkXuP+SeHreNq5TZ8k112cmpE0JV8S2wtjvdXNhxnTbCXZcybNaTyqZJeqiFoKn+kX8E6dNhPPYa9oRJt6iEswnLlLJNM+T0+lJME+zqULtDpsErU0i4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707779481; c=relaxed/simple; bh=IeqVsqHBBxkRlvWKuRk+BM+q2fCSQTabzCOE3hEGlcc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QsbRWtgiD28n0YCwOarpTDvPQUz1SgZqSPHDqfmL7TLdMRGoqBaY9Zf54ED+mafGr1DcHrtSWRGzigJ/vV+vvlWch36u7buYCPx4O/TLE2s3psK4k0VzDVsICerCVGm6LSEqbAVjujM+CUTyySOci0pqMFMryq9hMVQ9VZxuBKc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id C22F4C43394; Mon, 12 Feb 2024 23:11:19 +0000 (UTC) Date: Mon, 12 Feb 2024 18:12:02 -0500 From: Steven Rostedt To: Mete Durlu Cc: Sven Schnelle , Masami Hiramatsu , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH] tracing: use ring_buffer_record_is_set_on() in tracer_tracing_is_on() Message-ID: <20240212181202.70f47870@gandalf.local.home> In-Reply-To: <957e4c37-954f-4c35-98ba-df5edde4b5ce@linux.ibm.com> References: <20240205065340.2848065-1-svens@linux.ibm.com> <20240205075504.1b55f29c@rorschach.local.home> <20240205092353.523cc1ef@rorschach.local.home> <20240206060113.39c0f5bc@rorschach.local.home> <20240207060923.182ecb55@rorschach.local.home> <9a062196-ccbe-440e-a2f9-23eb8c5eb837@linux.ibm.com> <20240207072812.4a29235f@rorschach.local.home> <20240207104703.071ee985@rorschach.local.home> <8c986cb3-61b3-4f65-81c9-ffcfa994390f@linux.ibm.com> <20240212135320.26f90f28@gandalf.local.home> <957e4c37-954f-4c35-98ba-df5edde4b5ce@linux.ibm.com> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 12 Feb 2024 23:54:00 +0100 Mete Durlu wrote: > On 2/12/24 19:53, Steven Rostedt wrote: > > > > Right, it will definitely force the race window to go away. > > > > Can you still trigger this issue with just Sven's patch and not this change? > Sven's patch makes the test cases much more resilient. I needed to ramp > up the load up to 4 stressors on a 4 core system before the test starts > to fail again. At this point it is fair to say that the system is under > significant load. > > The failing condition is now different, which tells me that > Sven's patch have already solved(or improved) the previous issue. > What is failing now: > > echo '** ENABLE TRACING' > enable_tracing > > cnt=`cnt_trace` > if [ $cnt -eq 0 ]; then > fail "Nothing found in trace" > fi > > Adding a sleep between enable_tracing and cnt_trace seems to improve the > situation a lot. (my guess is that, the trace writer isn't getting any > runtime before the test checks the trace output) > > echo '** ENABLE TRACING' > enable_tracing > > +sleep $SLEEP_TIME > cnt=`cnt_trace` > if [ $cnt -eq 0 ]; then > fail "Nothing found in trace" > fi > > Didn't see any failure while increasing the system load until 8 > stressors (this might have been luck). When system was under load with > 8 stressors, I have seen the test failing 2 out of 10 times. Definitely > an improvement over the current situation. > So, I plan on adding Sven's patch for my next pull request to Linus. I had forgotten it when I did my last one (largely due to traveling). I'll hold off a week to see if any other fixes come in. -- Steve