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From: John Dyson <dyson@dyson.iquest.net>
Message-Id: <199611251446.JAA01865@dyson.iquest.net>
Subject: Re: cvs commit: sys/i386/i386 locore.s swtch.s sys/i386/include pmap.h
To: peter@spinner.dialix.com (Peter Wemm)
Date: Mon, 25 Nov 1996 09:46:36 -0500 (EST)
Cc: phk@critter.tfs.com, freebsd-smp@freebsd.org
In-Reply-To: <199611251442.WAA01604@spinner.DIALix.COM> from "Peter Wemm" at Nov 25, 96 10:42:02 pm
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> 
> Naturally..  Since this is from interrupt context, we don't have a lot of
> choice about what we have to save...  The hardware saves some guff for
> us, the rest we must do..
> 
> > It just so happens that pdirs never move once created.  Could 
> > you possibly do a pushfl;cli;invltlb;popfl though?  That will
> > keep interrupts away, and also will make pdirs movable eventually.
> > (just kind of curious more than anything why/if cli/sti won't work
> > in the context that you are describing.)
> 
In the lowest level interrupt context, doesn't the machine turn interrupts
off anyway?  If you can bypass some of the default processing, the code
can be mega simple.
>
> cli
> invltlb
> lock inc counter
> hit EOI in APIC
> restore registers
> reti
> 

John