Subject: Re: Kernel copyin/out optimizations for ARM...
To: None <email@example.com>
From: David Laight <firstname.lastname@example.org>
Date: 03/12/2002 11:54:40
On Tue, Mar 12, 2002 at 10:38:39AM +0000, Richard Earnshaw wrote:
> I've always wondered why that code wasn't written using ldrt/strt for the
> user-space accesses. That would then use the hardware for permission
> checking and eliminate the most expensive part of that code (doing the tlb
> check manually).
not in ARM v3?
> Maybe there is some reason why that would not work (wrong page tables
Isn't there a problem that the cache is checked before the TLBs?
Maybe bound checking the address is enough?
Why did the 'move from/to previous address space' instructions that
the pdp-11 have disappear from most later systems?
David Laight: email@example.com