Date: Mon, 25 Nov 1996 21:27:57 +0800 From: Peter Wemm <peter@spinner.dialix.com> To: "John S. Dyson" <toor@dyson.iquest.net> Cc: phk@critter.tfs.com, freebsd-smp@freebsd.org Subject: Re: cvs commit: sys/i386/i386 locore.s swtch.s sys/i386/include pmap.h Message-ID: <199611251327.VAA01291@spinner.DIALix.COM> In-Reply-To: Your message of "Mon, 25 Nov 1996 08:12:16 EST." <199611251312.IAA01616@dyson.iquest.net>
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"John S. Dyson" wrote:
> > I hope John's not going to have too much of a heart attack.. :-] It doesn'
t
> > interfere with the pmap code or the vm system in general, apart from making
> > the maximum npkt space smaller by 4MB. I'm pretty sure I can get this
> > to fly tonight, and will probably be able to get rid of the idle procs
> > and smp_idleloop() in the process.
> >
> Don't worry, just feel free to ask for help (if you need it.)
Don't worry.. I will certainly yell "Help!!!" when I need it. :-)
OBTW, easy question. Is it safe to do a:
movl %cr3, %eax
movl %eax, %cr3
.. from a non-spl-maskable interrupt handler?
I'm thinking in terms of a lightning quick interprocessor interrupt to
force all cpu's to do an invltlb().
So far as I can see from a quick scan of the code, the only real loads of
%cr3 are during cpu_switch(), initialisation, and tlb flushes. cpu_switch()
does it from inside cli/sti so it's safe, init code is irrelevant at this
point, and I think the tlb flush is implicitly reentrant since it's
not changing the register.
Have I missed something?
> John
Cheers,
-Peter
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