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

From: Denys Vlasenko
Date: Tue Apr 22 2008 - 12:19:05 EST


On Tuesday 22 April 2008 16:28, Adrian Bunk wrote:
> > 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.

In busybox this trick is used extensively.

I don't know how to eliminate these unused parameters with less
intervention, but I also don't want to leave it unfixed.

I want to eventually reach the state with no warnings
about unused parameters.
--
vda
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