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From: Daniel Walker <dwalker@mvista.com>
To: James Morris <jmorris@namei.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: kfree(NULL)
Date: Fri, 21 Apr 2006 07:06:58 -0700	[thread overview]
Message-ID: <1145628419.20843.2.camel@localhost.localdomain> (raw)
In-Reply-To: <Pine.LNX.4.64.0604210322110.21429@d.namei>

On Fri, 2006-04-21 at 03:22 -0400, James Morris wrote:
> On Fri, 21 Apr 2006, Daniel Walker wrote:
> 
> > 	I included a patch , not like it's needed . Recently I've been
> > evaluating likely/unlikely branch prediction .. One thing that I found 
> > is that the kfree function is often called with a NULL "objp" . In fact
> > it's so frequent that the "unlikely" branch predictor should be inverted!
> > Or at least on my configuration. 
> 
> It would be helpful to collect some stats on this so we can look at the 
> ratio.

On my system it was roughly 31 million kfree(NULL) calls, to 4 million
calls with other values . That was over 4 hours of run time .

Daniel


  parent reply	other threads:[~2006-04-21 14:07 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-04-21  7:03 kfree(NULL) Daniel Walker
2006-04-21  7:22 ` kfree(NULL) James Morris
2006-04-21  8:54   ` kfree(NULL) Andrew Morton
2006-04-21 13:56     ` kfree(NULL) Vernon Mauery
2006-04-21 14:07       ` kfree(NULL) Dmitry Fedorov
2006-04-21 15:07         ` kfree(NULL) Jan Engelhardt
2006-04-21 19:22           ` kfree(NULL) Adrian Bunk
2006-04-21 20:30             ` kfree(NULL) Vernon Mauery
2006-04-21 20:54               ` kfree(NULL) Steven Rostedt
2006-04-21 21:38               ` kfree(NULL) Adrian Bunk
2006-04-22 11:56               ` kfree(NULL) Jörn Engel
2006-04-21 23:55     ` kfree(NULL) Paul Mackerras
2006-04-22  7:43       ` kfree(NULL) Pekka Enberg
2006-04-22  8:48         ` kfree(NULL) Paul Mackerras
2006-04-22 15:02           ` kfree(NULL) Pekka Enberg
2006-04-22 18:57           ` kfree(NULL) Hua Zhong
2006-04-22 19:05             ` kfree(NULL) Nick Piggin
2006-04-22 19:22               ` kfree(NULL) Hua Zhong
2006-04-22 19:25                 ` kfree(NULL) Nick Piggin
2006-04-22 20:18                   ` kfree(NULL) Jan Engelhardt
2006-04-23 16:50               ` kfree(NULL) Steven Rostedt
2006-04-22 11:34       ` kfree(NULL) Jesper Juhl
2006-04-21 14:06   ` Daniel Walker [this message]
     [not found] <63XWg-1IL-5@gated-at.bofh.it>
     [not found] ` <63YfP-26I-11@gated-at.bofh.it>
     [not found]   ` <63ZEY-45n-27@gated-at.bofh.it>
2006-04-21 15:25     ` kfree(NULL) Tilman Schmidt
2006-04-21 16:03       ` kfree(NULL) Daniel Walker
2006-04-21 17:48         ` kfree(NULL) Jörn Engel
2006-04-21 18:00         ` kfree(NULL) Steven Rostedt
2006-04-21 18:42           ` kfree(NULL) Daniel Walker
2006-04-21 18:56             ` kfree(NULL) Steven Rostedt
2006-04-21 19:26           ` kfree(NULL) Andrew Morton
  -- strict thread matches above, loose matches on Subject: below --
2006-04-21 21:02 kfree(NULL) Hua Zhong
2006-04-21 21:11 ` kfree(NULL) Daniel Walker
2006-04-21 21:36   ` kfree(NULL) Michael Buesch
2006-04-21 21:42 ` kfree(NULL) Andrew Morton
2006-04-21 21:48   ` kfree(NULL) Andrew Morton
2006-04-21 22:53   ` kfree(NULL) Hua Zhong
2006-04-21 22:58     ` kfree(NULL) Daniel Walker
2006-04-21 23:03       ` kfree(NULL) Hua Zhong
2006-04-21 23:25     ` kfree(NULL) Andrew Morton
2006-04-21 23:27     ` kfree(NULL) Andrew Morton
2006-04-22 11:18   ` kfree(NULL) Jan Engelhardt
2006-04-22 12:05 kfree(NULL) linux

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