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Date: Wed, 13 Jan 2010 15:54:56 +0100
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
       LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tracing, function_graph: simplify test for tracing
Message-ID: <20100113145454.GE5036@nowhere>
References: <4B4DB0B6.7040607@cn.fujitsu.com>
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On Wed, Jan 13, 2010 at 07:38:30PM +0800, Lai Jiangshan wrote:
> 
> For function_graph, a calling function is to be traced only when
> it is enabled or it is nested in a enabled function.
> 
> Current code uses TSK_TRACE_FL_GRAPH to test whether it is nested or not.
> read the code, we can get this:
> (trace->depth > 0) <==> (TSK_TRACE_FL_GRAPH is set)
> 
> trace->depth is more explicit to tell that it is nested.
> So we use trace->depth directly and simplify the code.
> 
> No functionality is changed.
> TSK_TRACE_FL_GRAPH is not removed now, it is left for future usage.
> 
> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
> ---


Looks prety good to me. Nice simplification, the less checks we
have in this hot path, the better.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>