From: Schrober <franzschrober@yahoo.de>
To: thomas <thomas@net.t-labs.tu-berlin.de>
Cc: Julian Calaby <julian.calaby@gmail.com>,
	linux-wireless@vger.kernel.org, johannes@sipsolutions.net,
	nbd@openwrt.org
Subject: Re: [PATCH] mac80211: correct size the argument to kzalloc in minstrel_ht
Date: Fri, 29 Jun 2012 09:50:57 +0200
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On Thursday 28 June 2012 22:00:41 thomas wrote:
> Hi Julian,
> 
> Compiler wise both of our suggestions will lead to the same machine code.
> So beside the matter of taste, I just followed the other overall usage
> pattern of kzalloc in minstrel_ht.
> And it seems to be explicitly using the struct type.

http://lxr.linux.no/linux/Documentation/CodingStyle

                Chapter 14: Allocating memory

The kernel provides the following general purpose memory allocators:
kmalloc(), kzalloc(), kcalloc(), vmalloc(), and vzalloc().  Please refer to
the API documentation for further information about them.

The preferred form for passing a size of a struct is the following:

        p = kmalloc(sizeof(*p), ...);

The alternative form where struct name is spelled out hurts readability and
introduces an opportunity for a bug when the pointer variable type is changed
but the corresponding sizeof that is passed to a memory allocator is not.

Casting the return value which is a void pointer is redundant. The conversion
from void pointer to any other pointer type is guaranteed by the C programming
language.
-- 
Franz Schrober