Re: [PATCH] xfs: #define out unused parameters ofxfs_bmap_add_free and xfs_btree_read_bufl

From: Adrian Bunk
Date: Tue Apr 22 2008 - 10:28:53 EST


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.
>
> Code size difference on 32-bit x86:
> 393457 2904 2952 399313 617d1 linux-2.6-xfs6-TEST/fs/xfs/xfs.o
> 393441 2904 2952 399297 617c1 linux-2.6-xfs7-TEST/fs/xfs/xfs.o
>...

Elimination of completely unused parameters makes sense, but IMHO using
such #define hacks for minuscule code size and stack usage advantages is
not worth it.

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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