Re: asm/uaccess.h reimplementation, patch. [was: Re: 2.1 kernel bloat revisited]

Jakub Jelinek (jj@sunsite.ms.mff.cuni.cz)
Sun, 30 Mar 1997 15:24:28 +0200 (MET DST)

> what about doing this:
>
> ptr &= current->mem_mask;
>
> where mem_mask is depending on what 'mode' we are: user or kernel. This
> restricts memory configurations to 2^N user-space virtual memory sizes ...
> Dave, is this acceptable on Sparc? [the trick is to make the user-space
> size 2^N, not physical memory ... thus we can have 3.5G physical memory
> setups too: 512M user-space virtual memory, 3.5G physical memory]

If you can, can this be arch dependent, ie. in current->tss.mem_mask?
At least on sparc64 we'll be doing it in a completely different way, which
will just take one insns for every user access...

.u$e.
Cheers .$$$$$:S
Jakub $"*$/"*$$
$.`$ . ^F
4k+#+T.$F
-------------------------------------------------------------- 4P+++"$"$ ---
Jakub Jelinek, jj@sunsite.mff.cuni.cz :R"+ t$$B
Administrator of SunSITE Czech Republic ___# $$$
MFF, Charles University, Prague | | R$$k
---------------------------------------------------------- dd. | Linux $!$
Give your Sparc a new beginning - SparcLinux ddd | Sparc $9$F
-------------------------------------------------------- '!!!!!$ !!#!`
!!!!!* .!!!!!`
'!!!!!!!W..e$$!!!!!!`
"~^^~ ^~~^