cvs commit: src/sys/i386/isa npx.c

Bruce Evans bde at zeta.org.au
Mon May 29 07:09:27 PDT 2006


On Mon, 29 May 2006, David Xu wrote:

> On Sunday 28 May 2006 21:58, Bruce Evans wrote:
>
>> OK if it is correct to not copy the environment.
>>
> I will revert changes, I think I should keep it safe as before.

Thanks.

I couldn't find any more details about this using google.

>> ... old CPUs (at least amd64 ones) that don't support mxcsr_mask
>> also don't support DAZ, so the correct mask for them is 0xFFBF.  These
>> complications are implemented in Linux's i386 so I suppose they are
>> no-ops at worst for non-amd64 CPUs.  Linux stores the mask in a global
>> variable.  I think this breaks the asymmetric SMP case more than
>> necessary.
> process migrates from one CPU to another, I don't think you can use such
> CPUs in same system if they are different in this case.

Only actually using DAZ is sure not to work.

> I haven't tried DAZ bit, will you fix it ?

No, not in -current, sorry.  I'll check your fix for it.

Bruce


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