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From: Ingo Molnar <mingo@elte.hu>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Steven Rostedt <srostedt@redhat.com>
Subject: Re: [PATCH 2/6] tracing: increase size of number of possible events
Date: Fri, 24 Apr 2009 09:12:24 +0200	[thread overview]
Message-ID: <20090424071224.GD24912@elte.hu> (raw)
In-Reply-To: <20090424043111.983189535@goodmis.org>


* Steven Rostedt <rostedt@goodmis.org> wrote:

> From: Steven Rostedt <srostedt@redhat.com>
> 
> With the new event tracing registration, we must increase the number
> of events that can be registered. Currently the type field is only
> one byte, which leaves us only 256 possible events.
> 
> Since we do not save the CPU number in the tracer anymore (it is determined
> by the per cpu ring buffer that is used) we have an extra byte to use.
> 
> This patch increases the size of type from 1 byte (256 events) to
> 2 bytes (65,536 events).
> 
> It also adds a WARN_ON_ONCE if we exceed that limit.
> 
> [ Impact: allow more than 255 events ]

> -	int			type;
> +	unsigned short		type;

Hm, the changelog is not valid anymore - as here we really cut it 
down from 4 billion to 64K, right?

	Ingo

  parent reply	other threads:[~2009-04-24  7:13 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-24  4:30 [PATCH 0/6] [GIT PULL] x86,ring_buffer,tracing: updates for tip Steven Rostedt
2009-04-24  4:30 ` [PATCH 1/6] tracing/wakeup: move access to wakeup_cpu into spinlock Steven Rostedt
2009-04-24  4:30 ` [PATCH 2/6] tracing: increase size of number of possible events Steven Rostedt
2009-04-24  6:02   ` Li Zefan
2009-04-24  7:09     ` Ingo Molnar
2009-04-24 12:29       ` Steven Rostedt
2009-04-24 12:27     ` Steven Rostedt
2009-04-24 14:04     ` Steven Rostedt
2009-04-24 14:05       ` Steven Rostedt
2009-04-26  6:53         ` Li Zefan
2009-04-26 13:44           ` Steven Rostedt
2009-05-04  9:05             ` Li Zefan
2009-05-04 14:12               ` Steven Rostedt
2009-05-05  1:32                 ` Li Zefan
2009-05-07  9:19               ` [tip:tracing/core] tracing: reset ring buffer when removing modules with events tip-bot for Steven Rostedt
2009-04-24  7:12   ` Ingo Molnar [this message]
2009-04-24 12:30     ` [PATCH 2/6] tracing: increase size of number of possible events Steven Rostedt
2009-04-24  4:30 ` [PATCH 3/6] tracing: add size checks for exported ftrace internal structures Steven Rostedt
2009-04-24  4:30 ` [PATCH 4/6] x86: use native register access for native tlb flushing Steven Rostedt
2009-04-24  4:30 ` [PATCH 5/6] tracing: fix cut and paste macro error Steven Rostedt
2009-04-24  4:30 ` [PATCH 6/6] ring_buffer: compressed event header Steven Rostedt

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