lkml.org 
[lkml]   [2008]   [Oct]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] x86: Add clflush before monitor for Intel 7400 series
From
Date
"H. Peter Anvin" <hpa@zytor.com> writes:

> Pallipadi, Venkatesh wrote:
>>>>
>>> I guess I'm a bit confused about the tradeoff of CLFLUSH versus simply
>>> disabling MWAIT. This is a relatively recent processor and so
>>> optimizing matters (if this was a P4 I would be more worried about what
>>> has least impact on the kernel as a whole.)
>> As of now this is only for a limited models of CPUs (MP CPUs)
>> and not a norm. It is a errata on this CPU and not
>> something that is going to become architectural.
>>
>
> Yes, I understand. However, there is still the option to disable
> MWAIT, and the question is still open if it makes sense.

This would mean falling back to the IO port interface for deeper
C states. Even with the CLFLUSH MWAIT is a much better (and I believe
faster) interface.

-Andi
--
ak@linux.intel.com


\
 
 \ /
  Last update: 2008-10-18 09:19    [W:0.036 / U:0.680 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site