lkml.org 
[lkml]   [2003]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: High Mem Options
On Wed, 5 Mar 2003 04:57:47 -0800, William Lee Irwin III wrote:
>> The cpu can't look at more than 4GB at a time.
>> Protected mode doesn't help this, turning paging on and PAE on does.
>> What it can do is point pagetables at different 4GB subsets of memory.
>> c.f. kmap_atomic() for how to window around using what's actually a
>> very small set of PTE's.

On Wed, Mar 05, 2003 at 02:02:57PM +0100, Michael Vergoz wrote:
> Right, but if the pagetable pointing to a different 4GB subsets of
> memory. The performance of the system can be disastrous, not?

Well, the TLB gets blown away at the drop of a hat. Things just have
lower scaling factors with respect to memory than say, 64-bit, though
Linux doesn't do anything about TLB coverage on 64-bit yet anyway.

It might be better to take this one to kernelnewbies@nl.linux.org


-- wli
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:33    [W:0.030 / U:0.272 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site