lkml.org 
[lkml]   [2000]   [Sep]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Question: Using floating point in the kernel
Date
On Wed, 20 Sep 2000 22:37:29 -0700, "Lyle Coder" <x_coder@hotmail.com>
wrote:

>Hi
>The real issue is that if you use MMX or FP state, the kernel _must_ save
>and restore the original state other wise user programs will see corruption.
>We all know this too well since redhat's 6.1 (I think) kernel had this
>optimized MMX functions that _screwed_ up user programs. The fact is... it
>is tricky to save and restore state (device not available and all).
>The basic kernel itself does not provide support for kernel code to use
>these registers. If some device drivers or some modifications to the kernel
>are using it.. then I hope they have the save/restore path right

A 2.5-time problem is that portions of the kernel are planned to
become interruptible... so saving and restoring around a certain usage
would be insufficient.

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

\
 
 \ /
  Last update: 2005-03-22 12:38    [W:0.151 / U:0.196 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site