From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [PATCH 2/3][RFC] tracing: Add optional percpu buffers for trace_printk()
Date: Mon, 10 Oct 2011 13:08:33 +0200 [thread overview]
Message-ID: <1318244913.14400.19.camel@laptop> (raw)
In-Reply-To: <20111008171259.462646120@goodmis.org>
On Sat, 2011-10-08 at 13:02 -0400, Steven Rostedt wrote:
>
> Ideally, using percpu buffers would be useful, but since trace_printk()
> is only used in development, having per cpu buffers for something
> never used is a waste of space. We could make this a compile option
> but trace_printk() may also be used for developing modules, on a
> distro kernels or for debugging at customer sites.
>
> The approach taken here is to dynamically allocate percpu buffers
> with a new tracing/options switch "trace_printk_percpu". It can
> be allocated and freed at runtime, or "trace_printk_percpu" may also
> be specified on the command line and it will be allocated at boot up.
>
> This allows a developer to create percpu buffers for trace_printk()
> on a running system, and also free them when not in used.
Kill the old code, make tracing/events/trace_printk default to 0 and use
enabling of that to allocate your per-cpu buffers.
next prev parent reply other threads:[~2011-10-10 11:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-08 17:02 [PATCH 0/3][RFC] trace_printk() using percpu buffers Steven Rostedt
2011-10-08 17:02 ` [PATCH 1/3][RFC] tracing: Do not allocate buffer for trace_marker Steven Rostedt
2011-10-08 17:02 ` [PATCH 2/3][RFC] tracing: Add optional percpu buffers for trace_printk() Steven Rostedt
2011-10-10 11:08 ` Peter Zijlstra [this message]
2011-10-10 12:37 ` Steven Rostedt
2011-10-10 13:04 ` Peter Zijlstra
2011-10-10 13:17 ` Steven Rostedt
2011-10-08 17:02 ` [PATCH 3/3][RFC] tracing: Add config to permanently have trace_printk() use percpu Steven Rostedt
2011-10-10 11:04 ` [PATCH 0/3][RFC] trace_printk() using percpu buffers Peter Zijlstra
2011-10-10 12:31 ` Steven Rostedt
2011-10-10 13:03 ` Peter Zijlstra
2011-10-10 13:06 ` Steven Rostedt
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