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Date: Tue, 6 May 2003 09:13:19 -0400 (EDT)
From: Daniel Eischen <eischen@pcnet1.pcnet.com>
To: Julian Elischer <julian@elischer.org>
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cc: threads@freebsd.org
cc: David Xu <davidxu@freebsd.org>
Subject: Re: kern_threads.c..  upcall question..
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On Tue, 6 May 2003, Julian Elischer wrote:
> 
> On Tue, 6 May 2003, David Xu wrote:
> 
> > 
> > > I think this could be optimised even more.
> > > (why copy the FP regs if they are not valid) (etc).
> > > but it is an improvement..
> > > 
> > 
> > Why need we an intermediate mcontext_t, why not
> > direct copy the context in trap frame to userland space?
> > This should be fastest. :-)
> 
> this is what I was thinking..
> get_mcontext_user(td, addr)
> [...]

Don't break validation and setting of FP validity and type.
get_mcontext() knows how to mark the validity of the FPU
set and it's type (387 or SSE).  The UTS relies on this
information.  Be very careful.

-- 
Dan Eischen