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From: Andrew Morton <akpm@linux-foundation.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
	Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [PATCH 3/3] ring-buffer: make cpu buffer entries counter atomic
Date: Thu, 30 Apr 2009 20:06:07 -0700	[thread overview]
Message-ID: <20090430200607.9fc386ae.akpm@linux-foundation.org> (raw)
In-Reply-To: <20090501022403.826182932@goodmis.org>

On Thu, 30 Apr 2009 22:22:13 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:

> @@ -405,7 +405,7 @@ struct ring_buffer_per_cpu {
>  	unsigned long			nmi_dropped;
>  	unsigned long			commit_overrun;
>  	unsigned long			overrun;
> -	unsigned long			entries;
> +	atomic_t			entries;

This switches `entries' from unsigned-64-bit to signed-32-bit.

The signedness thing is just an unfortunate thing with atomic_t and probably
doesn't matter.

The change in size might or might not be a bug - that's for the person
who didn't document the data structure to work out ;)




/*
 * head_page == tail_page && head == tail then buffer is empty.
 */
struct ring_buffer_per_cpu {

the comment refers to vaporfields?

  reply	other threads:[~2009-05-01  3:09 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-01  2:22 [PATCH 0/3] [GIT PULL] tracing/ringbuffer: updates for tip Steven Rostedt
2009-05-01  2:22 ` [PATCH 1/3] ring-buffer: add counters for commit overrun and nmi dropped entries Steven Rostedt
2009-05-01  3:00   ` Andrew Morton
2009-05-01  3:11     ` Steven Rostedt
2009-05-01  3:22       ` Andrew Morton
2009-05-01  3:33         ` Steven Rostedt
2009-05-01  3:38           ` Andrew Morton
2009-05-01  3:55             ` Steven Rostedt
2009-05-01  2:22 ` [PATCH 2/3] tracing: export stats of ring buffers to userspace Steven Rostedt
2009-05-01  3:08   ` Frederic Weisbecker
2009-05-01  3:23     ` Steven Rostedt
2009-05-01 12:43       ` Frederic Weisbecker
2009-05-01  2:22 ` [PATCH 3/3] ring-buffer: make cpu buffer entries counter atomic Steven Rostedt
2009-05-01  3:06   ` Andrew Morton [this message]
2009-05-01  3:28     ` Steven Rostedt
2009-05-01 11:50   ` Ingo Molnar
2009-05-01 13:42     ` Frederic Weisbecker
2009-05-01 14:28       ` Steven Rostedt
2009-05-01 22:10         ` Frederic Weisbecker
2009-05-01 14:23     ` Steven Rostedt
2009-05-01 16:14       ` Steven Rostedt
2009-05-01 16:20         ` Ingo Molnar
2009-05-01 16:31           ` Steven Rostedt
2009-05-01 16:32             ` Steven Rostedt
2009-05-01 16:52             ` Ingo Molnar
2009-05-01 17:11               ` Steven Rostedt
2009-05-01 17:14                 ` Ingo Molnar
2009-05-01 17:36                   ` Steven Rostedt
2009-05-01 17:42                     ` Ingo Molnar
2009-05-01 17:56                       ` Steven Rostedt
2009-05-01 21:17                         ` Steven Rostedt

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