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From: Robert Hancock <hancockr@shaw.ca>
To: Tim Bird <tim.bird@am.sony.com>
Cc: linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: kfree(0) - ok?
Date: Tue, 14 Aug 2007 17:05:04 -0600	[thread overview]
Message-ID: <46C23520.2070805@shaw.ca> (raw)
In-Reply-To: <fa.oMJ6o9vN0dnAoFR83/o4hg1EptE@ifi.uio.no>

Tim Bird wrote:
> Hi all,
> 
> I have a quick question.
> 
> I'm trying to resurrect a patch from the Linux-tiny patch suite,
> to do accounting of kmalloc memory allocations.  In testing it
> with Linux 2.6.22, I've found a large number of kfrees of
> NULL pointers.
> 
> Is this considered OK?  Or should I examine the offenders
> to see if something is coded badly?

It's perfectly correct to do it - though, if it's done very frequently 
in certain cases, it might be more efficient to check for null before 
the kfree, to avoid the function call overhead into kfree..

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/


       reply	other threads:[~2007-08-14 23:05 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <fa.oMJ6o9vN0dnAoFR83/o4hg1EptE@ifi.uio.no>
2007-08-14 23:05 ` Robert Hancock [this message]
2007-08-14 22:59 kfree(0) - ok? Tim Bird
2007-08-14 22:55 ` Arjan van de Ven
2007-08-14 23:21   ` Jason Uhlenkott
2007-08-15  7:28     ` Jan Engelhardt
2007-08-15  8:37       ` Rene Herman
2007-08-15  9:20         ` Jan Engelhardt
2007-08-15  9:43           ` Jason Uhlenkott
2007-08-15  9:58           ` Rene Herman
2007-08-15 10:20             ` Jan Engelhardt
2007-08-15 10:27               ` Rene Herman
2007-08-15 13:58               ` Kyle Moffett
2007-08-15 14:06                 ` Jan Engelhardt
2007-08-15 14:34                   ` Kyle Moffett
2007-08-15 16:01               ` H. Peter Anvin
2007-08-15  8:52       ` Jason Uhlenkott
2007-08-15  9:18       ` Andreas Schwab
2007-08-15  9:32       ` Giacomo A. Catenazzi
2007-08-14 23:42   ` Satyam Sharma
2007-08-15  0:19     ` Christoph Lameter
2007-08-17 18:22     ` Andrew Morton
2007-08-17 18:31       ` Arjan van de Ven
2007-08-17 18:50         ` Satyam Sharma
2007-08-17 18:37       ` Jan Engelhardt
2007-08-17 20:43       ` Christoph Lameter
2007-08-17 21:17         ` Satyam Sharma
2007-08-17 21:32           ` Satyam Sharma
2007-08-17 21:13       ` Satyam Sharma
2007-08-17 21:14         ` Christoph Lameter
2007-08-17 21:42           ` Pekka Enberg
2007-08-17 23:22             ` Christoph Lameter
2007-08-17 23:40             ` Thomas Gleixner
2007-08-18  0:02               ` Satyam Sharma
2007-08-18  1:03               ` Christoph Lameter
2007-08-18  8:10               ` Pekka Enberg
2007-08-18  8:21               ` Jan Engelhardt
2007-08-17 21:46           ` Satyam Sharma
2007-08-14 23:13 ` Satyam Sharma

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