Re: CVS commit: src/sys/arch/mips/mips

[David Holland <dholland-sourcechanges%netbsd.org@localhost>]

On Mon, Nov 08, 2010 at 06:09:39PM +0000, Antti Kantee wrote:
 > Modified Files:
 >      src/sys/arch/mips/mips: locore_mips1.S
 > 
 > Log Message:
 > In TLBRead, restore PID before doing the saves so that the caller's
 > TLB entries are used instead of the PID given as the argument.
 > 
 > from Alessandro Forin

This doesn't make any sense.

As far as I can tell, the real problem is that the code is not
attending to pipeline hazards properly; moving things around until it
experimentally seems to work is just going to create other odd
behavior sometime down the line under different timing circumstances.

I don't have a mips1-specific reference on hand, but my recollection
is that you need *three* nops when messing with cop0 registers for all
effects to flush through.

Do you have any further explanations or reports of symptoms? I don't
see anything on any of the mips lists.

-- 
David A. Holland
dholland%netbsd.org@localhost