linux-kernel - Re: kfree(0)

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Message-id: <46C23520.2070805@shaw.ca>
Date:	Tue, 14 Aug 2007 17:05:04 -0600
From:	Robert Hancock <hancockr@...w.ca>
To:	Tim Bird <tim.bird@...sony.com>
Cc:	linux kernel <linux-kernel@...r.kernel.org>
Subject: Re: kfree(0) - ok?

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@...pamshaw.ca
Home Page: http://www.roberthancock.com/

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