linux-kernel - Re: [PATCH] tracing: Cleanup the convoluted softirq tracepoints

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Message-ID: <4CBE251A.6070603@zytor.com>
Date:	Tue, 19 Oct 2010 16:09:14 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Steven Rostedt <rostedt@...dmis.org>
CC:	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Koki Sanagi <sanagi.koki@...fujitsu.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...e.hu>,
	Frederic Weisbecker <fweisbec@...il.com>,
	nhorman@...driver.com, scott.a.mcmillan@...el.com,
	laijs@...fujitsu.com, LKML <linux-kernel@...r.kernel.org>,
	eric.dumazet@...il.com, kaneshige.kenji@...fujitsu.com,
	David Miller <davem@...emloft.net>, izumi.taku@...fujitsu.com,
	kosaki.motohiro@...fujitsu.com,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	"Luck, Tony" <tony.luck@...el.com>, Jason Baron <jbaron@...hat.com>
Subject: Re: [PATCH] tracing: Cleanup the convoluted softirq tracepoints

On 10/19/2010 04:05 PM, Steven Rostedt wrote:
>>
>> JMP/Jcc does have a consumer -- the IP -- and actually measuring shows
>> that it is much, much worse than NOP and other dummy instructions.
> 
> But how does JMP vs Jcc compare?
> 

*As far as I know* they're the same, except of course that a direct JMP
never mispredicts.

	-hpa
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