Re: What I suspect
Rogier Wolff (R.E.Wolff@BitWizard.nl)
Wed, 8 Dec 1999 12:03:10 +0100 (MET)
Alexander Viro wrote:
>
>
> On Wed, 8 Dec 1999, Rogier Wolff wrote:
>
> > Linus Torvalds wrote:
> > > So I've considered having a magic user-mapped page for quite some time,
> > > because we have several of these cases where the kernel can generate code
> > > at run-time to its own advantage. The sysenter thing is just an obvious
> > > extension to this - allowing the kernel to generate whatever entry
> > > sequence is the best for that particular CPU.
> >
> > Talking about "magic user-mapped pages": Some things like "getpid ()"
> > are horrendously more inefficient than they need be. If there was a
> > magic kernel-page that the user-app has read access to, then these
> > calls would become enormously more efficient.
>
> And there goes any talk about not screwing TLB over this thing...
Right. But if your application happens to profit from the MEGA_FAST
access to "getpid" and the likes, it is not a bad idea to have the
tlb allocated for this use.
If you DON"T call getpid and friends, your application won't get the
tlb entry allocated right?
Roger.
--
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
"I didn't say it was your fault. I said I was going to blame it on you."
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