On Sat, Mar 03, 2012 at 03:17:32AM +0000, Takeshi Nakayama wrote:
> Module Name: src
> Committed By: nakayama
> Date: Sat Mar 3 03:17:32 UTC 2012
>
> Modified Files:
> src/sys/arch/sparc64/sparc64: locore.s
>
> Log Message:
> Fix the root cause of the hack "disable optimizations for uvm_bio.c
> on 32 bit kernels".
>
> gcc converts a division in the calculation of UBC_UMAP_ADDR macro
> to multiplication (smul or combination of add/sll), and the
> register of its result contains a garbage in upper 32 bits (the
> upper 32 bits of smul/add/sll's result isn't zero cleared).
>
> Then it passes to pseg_get{,_real} through pmap_extract without the
> zero clear of upper 32 bits in the optimization case. So the
> result of pseg_get and pmap_extact sometimes gets screwed up.
Oh, good catch!
Thanks for fixing this one.
Best,
Al
