Re: i386 PDA patches use of %gs

[Ingo Molnar]

* Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:

> > that loads (and uses) a single selector value for %fs, and doesnt do 
> > any mixed use as far as i can see.
> 
> I'm not sure what you're getting at.  Each loop iteration is analogous 
> to a user->kernel->user transition with respect to the 
> save/reload/use/restore pattern on the segment register.  In this 
> case, %fs starts as a null selector, gets reloaded with a non NULL 
> selector, and then is restored to null.  Do you mean some other 
> mixing?

yeah, mixed use: i.e. set up /two/ selector values and load them into 
%gs and read+write memory through them. It might not change the results, 
but that's what i meant under 'mixed use'.

	Ingo
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