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Date: Mon, 7 Jan 2002 18:57:27 -0700
To: Alfred Perlstein <bright@mu.org>
Cc: Nate Williams <nate@yogotech.com>,
	Dan Eischen <eischen@vigrid.com>, Peter Wemm <peter@wemm.org>,
	Archie Cobbs <archie@dellroad.org>, arch@FreeBSD.ORG
Subject: Re: Request for review: getcontext, setcontext, etc
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> > > > > threads.
> > > > > 
> > > > > Is this possible?
> > > > 
> > > > In the future it may be possible, if we keep track of FP-usage on a
> > > > thread basis instead of a process basis.  This requires kernel threads.
> > > 
> > > No, as I stated above, I don't think this requires kernel threads.
> > 
> > I understand now, thanks.  However, I'm not sure how easily this can be
> > done.
> 
> All you need is a hook to reset the FP-used bit, any application
> that clears the bit incorrectly gets what it deserves. :)

That's the easy part.  The hard part is setting the 'need-FPU' bit in
the process, and making sure to catch the FPU exception, resetting the
bit in the thread, then making sure the FPU is retried safely.


Nate

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