lkml.org 
[lkml]   [2010]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: Export tsc related information in sysfs
On 05/18/2010 09:52 AM, Peter Zijlstra wrote:
> On Tue, 2010-05-18 at 09:40 -0700, H. Peter Anvin wrote:
>>
>> The problem is that you throw the baby (vsyscall) out with the bathwater
>> (user rdtsc).
>
> Well, we could only flip the CR4 bit when we mark the TSC unsuitable for
> gtod. That should be plenty good to tag all userspace trying to use it,
> since more than half my machines don't use TSC for clocksource.

This might be an option, although it would have to be an *option*.
There are restricted uses of the TSC in userspace which are still useful
(mainly involving performance analysis and/or CPU-locked processes).

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.



\
 
 \ /
  Last update: 2010-05-18 19:11    [W:0.063 / U:41.728 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site