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Date: Wed, 23 Apr 2008 08:43:09 +1000
From: David Chinner <dgc@sgi.com>
To: Denys Vlasenko <vda.linux@googlemail.com>
Cc: David Chinner <dgc@sgi.com>, Eric Sandeen <sandeen@sandeen.net>,
       Adrian Bunk <bunk@kernel.org>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
       Shawn Bohrer <shawn.bohrer@gmail.com>, Ingo Molnar <mingo@elte.hu>,
       Andrew Morton <akpm@linux-foundation.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Arjan van de Ven <arjan@infradead.org>,
       Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] xfs: #define out unused parameters of xfs_bmap_add_free and xfs_btree_read_bufl
Message-ID: <20080422224309.GW108924158@sgi.com>
References: <20080419142329.GA5339@elte.hu> <200804221142.00914.vda.linux@googlemail.com> <200804221216.25905.vda.linux@googlemail.com> <200804221320.54147.vda.linux@googlemail.com>
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On Tue, Apr 22, 2008 at 01:20:54PM +0200, Denys Vlasenko wrote:
> Hi David,
> 
> xfs_bmap_add_free and xfs_btree_read_bufl functions
> use some of their parameters only in some cases
> (e.g. if DEBUG is defined, or on non-Linux OS :)
> 
> This patch removes these parameters using #define hack
> which makes them "disappear" without the need of uglifying
> every callsite with #ifdefs.

We don't use pre-processor hacks to hide function variables for different
config options.  The XFS header files are messy enough without adding
additional redefinitions of function types to them.

w.r.t xfs_bmap_add_free(), the correct thing to do is to factor the
debug code out into a different function that is only compiled
on debug kernels and remove all the debug checks from xfs_bmap_add_free().

As it is, I don't think that the change is worth the maintenance
cost for a few bytes of stack space in non-critical paths.

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group