lkml.org 
[lkml]   [2002]   [Dec]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Intel P6 vs P7 system call performance
Ingo Molnar wrote:
> On Tue, 24 Dec 2002, Linus Torvalds wrote:
>
>
>>I realized that there is really no reason to use __KERNEL_DS for this,
>>and that as far as the kernel is concerned, the only thing that matters
>>is that it's a flat 32-bit segment. So we might as well make the kernel
>>always load ES/DS with __USER_DS instead, which has the advantage that
>>we can avoid one set of segment loads for the "sysenter/sysexit" case.
>
>
> this basically hardcodes flat segment layout on x86. If anything (Wine?)
> modifies the default segments, it can wrap syscalls by saving/restoring
> the modified %ds and %es selectors explicitly.
>

I don't think you can modify the GDT segments.

-hpa

P.S. Please don't use my @transmeta.com address for non-Transmeta
business. I'm trying very hard to keep my mailboxes semi-organized.



-
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 13:31    [W:0.082 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site