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 8683484A3B; Fri, 21 Jun 2024 08:01:02 +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=1718956862; cv=none; b=MF3xSjdjG7cqYli0u+jqu6rh9fZfqgiMvJa+kIU7A6NP+Kc5AKKLnKCo8MidXeyqafooo+izDZIjNWS4uA0q8+Eq5gq6PUi7sUD8x0x3tReq17NH+POJLYrjDoHC26/mwXZUe4C3AjVRglVopiu2FaG8Vy87xR88Th7sNlwGNys= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718956862; c=relaxed/simple; bh=79uHlnttJepyz6wjLqBHqDBH9rnuTEAmit5+JYFFtgI=; h=Message-ID:Date:MIME-Version:Subject:To:References:Cc:From: In-Reply-To:Content-Type; b=Pa6MEtDf5Ecijh+NHB4yDrUPD0am2bwGJDzFOs5vcf6iw454hDOm6rVHGAp97NewFDWeNeYPon1FiQq1f1hjub0uvhg/YnhDMVqFneIAJR8JcixUpINKo2kljwiArdvEh+GXNzM2j2fvrC8rZLPYZIBs2hZmUDE3l47JT4WDGvw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=u7l2ga2O; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="u7l2ga2O" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27D97C4AF07; Fri, 21 Jun 2024 08:00:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718956862; bh=79uHlnttJepyz6wjLqBHqDBH9rnuTEAmit5+JYFFtgI=; h=Date:Subject:To:References:Cc:From:In-Reply-To:From; b=u7l2ga2OpM+1ELNAwlwCWVUVHmHa47s8I/9/KEB4vCZAvhSwWHWUqzdIFI6JGwYjP j7W3fDOkdkiet4895wDHQf00kYB1BO9UgW8gw4t0PhlQ6biGCpxqcU/PBHY9kXvT9t acoqyfgdhwxaAzMj3vITW9yOBUhdpjJaUx2FIe82tDnKWng7qU3Nq6bvi/9WrFISxD UTwd3Zv2Ntq/7020K+hVyLEgSNgoxmb8FLQeW8hp2eoce2WInO/pvFqbfafwhChGG4 RUk9ply8M+T3hossQa9SSizJO4SPdIRrWCg+NktimMut0QrZrW38TLjsQ0imt2B8CG RTN6I8Zd7DmEA== Message-ID: <101b0854-7b39-486d-af63-4fe72566e8e1@kernel.org> Date: Fri, 21 Jun 2024 10:00:52 +0200 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] rtla/osnoise: set the default threshold to 1us To: "Luis Claudio R. Goncalves" , Steven Rostedt References: Content-Language: en-US, pt-BR, it-IT Cc: Mathieu Desnoyers , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Masami Hiramatsu From: Daniel Bristot de Oliveira In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Luis, This is not rtla/osnoise but tracing/osnoise, so the Subject would be: [PATCH] tracing/osnoise: Set the default threshold to 1 us On 6/10/24 15:23, Luis Claudio R. Goncalves wrote: > Change the default threshold for osnoise to 1us, so that any noise > equal or above this value is recorded. Let the user set a higher > threshold if necessary. The reason why I place fear instead of one was "fear" of having the loop taking more then one us, creating false noise notifications because of execution time. But it actually never happened, even on low speed arm boxes... Also, all users I know are setting it to 1 on rtla... so I think it is safe to move the value to 1. Acked-by: Daniel Bristot de Oliveira > Suggested-by: Daniel Bristot de Oliveira > Reviewed-by: Clark Williams > Signed-off-by: Luis Claudio R. Goncalves > --- > Documentation/trace/osnoise-tracer.rst | 2 +- > kernel/trace/trace_osnoise.c | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/Documentation/trace/osnoise-tracer.rst b/Documentation/trace/osnoise-tracer.rst > index 140ef2533d26a..a520adbd34765 100644 > --- a/Documentation/trace/osnoise-tracer.rst > +++ b/Documentation/trace/osnoise-tracer.rst > @@ -108,7 +108,7 @@ The tracer has a set of options inside the osnoise directory, they are: > option. > - tracing_threshold: the minimum delta between two time() reads to be > considered as noise, in us. When set to 0, the default value will > - be used, which is currently 5 us. > + be used, which is currently 1 us. > - osnoise/options: a set of on/off options that can be enabled by > writing the option name to the file or disabled by writing the option > name preceded with the 'NO\_' prefix. For example, writing > diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c > index a8e28f9b9271c..66a871553d4a1 100644 > --- a/kernel/trace/trace_osnoise.c > +++ b/kernel/trace/trace_osnoise.c > @@ -1444,9 +1444,9 @@ static int run_osnoise(void) > save_osn_sample_stats(osn_var, &s); > > /* > - * if threshold is 0, use the default value of 5 us. > + * if threshold is 0, use the default value of 1 us. > */ > - threshold = tracing_thresh ? : 5000; > + threshold = tracing_thresh ? : 1000; > > /* > * Apply PREEMPT and IRQ disabled options.