[parisc-linux] alternate insn for parisc (ccio/sba)

[Randolph Chung]

> Anyplace we use asm that could be different for PA20 vs PA11.
> __ffs() in include/asm/bitops.h probaby isn't the best example
> but it might be good enough to give an idea.
> Ie kernel built for PA11 could be optimized for PA20-32bit.

Just my 2 cents, but unless it is code that is performance critical and
we can demonstrate a significant difference on a particular measurement,
and it is not something that can be determined at compile time, I think
we should do runtime code patching sparingly. If nothing else, it makes
the code harder to read and perhaps to debug.

>> Also, if you want to test it, you'll need to remove the & ~_PAGE_WRITE from
>> PAGE_KERNEL_RO in asm/pgtable.h until we write protect the kernel at a
>> later stage.

Right - it seems we should re-map the kernel read-only after you patch
the insns.

> very cool! ++kyle. :)

it is cool, thanks for working on this, Kyle.

randolph
-- 
Randolph Chung
Debian GNU/Linux Developer, hppa/ia64 ports
http://www.tausq.org/