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SubjectRe: [RFC] asm-generic: default BUG_ON(x) to "if(x) BUG()"
Date
On Monday 23 November 2015 16:37:50 Russell King - ARM Linux wrote:
> On Mon, Nov 23, 2015 at 05:33:59PM +0100, Willy Tarreau wrote:
> > I think you could do better by simply calling panic("BUG!") instead as
> > BUG() does. It will avoid the printk() call and pushing the file/line
> > number onto the stack. It will also probably not inflate the rodata this
> > way.
>
> Does that not depend on the architectures BUG() implementation? If an
> architecture implements it as a signalling illegal instruction and a
> lookup table, changing it to be a panic() would probably be more code.

Correct, overall, we are down to a 1.40% size reduction compared to
1.70% without my patch and 1.49% with my version:

section CONFIG_BUG=y CONFIG_BUG=n CONFIG_BUG=n+patch panic("BUG!")

.text 8320248 | 8180944 | 8207688 | 8221848
.rodata 3633720 | 3567144 | 3570648 | 3567344
__bug_table 32508 | --- | --- | ---
__modver 692 | 1584 | 2176 | 1384
.init.text 558132 | 548300 | 550088 | 550592
.exit.text 12380 | 12256 | 12380 | 12448
.data 1016672 | 1016064 | 1016128 | 1016064
Total 14622556 | 14374510 | 14407326 | 14417898

Arnd


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