Received-SPF: pass (google.com: domain of linux-kernel+bounces-56363-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Wed, 7 Feb 2024 06:09:23 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Sven Schnelle <svens@linux.ibm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>, Mathieu Desnoyers
 <mathieu.desnoyers@efficios.com>, linux-kernel@vger.kernel.org,
 linux-trace-kernel@vger.kernel.org, Mete Durlu <meted@linux.ibm.com>
Subject: Re: [PATCH] tracing: use ring_buffer_record_is_set_on() in
 tracer_tracing_is_on()
Message-ID: <20240207060923.182ecb55@rorschach.local.home>
In-Reply-To: <yt9deddovn3w.fsf@linux.ibm.com>
References: <20240205065340.2848065-1-svens@linux.ibm.com>
	<20240205075504.1b55f29c@rorschach.local.home>
	<yt9djznj3vbl.fsf@linux.ibm.com>
	<20240205092353.523cc1ef@rorschach.local.home>
	<yt9d34u63xxz.fsf@linux.ibm.com>
	<yt9dsf262d2n.fsf@linux.ibm.com>
	<20240206060113.39c0f5bc@rorschach.local.home>
	<yt9deddovn3w.fsf@linux.ibm.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

On Wed, 07 Feb 2024 06:50:59 +0100
Sven Schnelle <svens@linux.ibm.com> wrote:

> Hi Steven,

> Not sure whether that is enough, have to test. However, it's not really
> a fix, it would just require a bit more load and the test would fail
> again. The fundamental problem is that even after disabling tracing
> there might be some tracing line added due to the lockless nature of
> the ringbuffer. This might then replace some existing cmdline entry.
> So maybe we should change the test to ignore the program name when
> calculating the checksums.

Have you figured out what caused the cmdlines to change when tracing is
off. It shouldn't be updated even with just 128 entries.

I'm also looking into a way to keep more of a LRU command lines around,
but nothing concrete yet.

-- Steve