lkml.org 
[lkml]   [2011]   [Aug]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [uml-devel] SYSCALL, ptrace and syscall restart breakages (Re: [RFC] weird crap with vdso on uml/i386)
On 08/23/2011 02:10 PM, Borislav Petkov wrote:
> On Tue, Aug 23, 2011 at 05:06:03PM -0400, H. Peter Anvin wrote:
>> On 08/23/2011 01:56 PM, Borislav Petkov wrote:
>>>
>>> But no, I don't think the difference has disappeared - to the contrary,
>>> AFAICT, the intention is for SYSCALL to be the fastest way to do
>>> syscalls on x86 due to diminished number of segment checks etc. INT80
>>> is legacy, slower, etc. I believe Andy measured a similar situation on
>>> Sandy Bridge with SYSCALL having latencies in the tens of nsecs range
>>> and INT80 being much slower. Ingo also measured a similar situation
>>> where the latency gap between the two on Intel is even bigger.
>>>
>>
>> Sandy Bridge doesn't have SYSCALL32 at all. It has SYSENTER and SYSCALL64.
>
> Yeah, I was talking about SYSCALL in general.
>

Right, but there could be an arbitrary chasm between SYSCALL32 and
SYSCALL64.

-hpa



\
 
 \ /
  Last update: 2011-08-24 01:09    [W:0.599 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site