lkml.org 
[lkml]   [2020]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v5 2/9] x86/split_lock: Avoid runtime reads of the TEST_CTRL MSR
On Sun, Mar 15, 2020 at 01:05:10PM +0800, Xiaoyao Li wrote:
> In a context switch from a task that is detecting split locks
> to one that is not (or vice versa) we need to update the TEST_CTRL
> MSR. Currently this is done with the common sequence:
> read the MSR
> flip the bit
> write the MSR
> in order to avoid changing the value of any reserved bits in the MSR.
>
> Cache the value of the TEST_CTRL MSR when we read it during initialization
> so we can avoid an expensive RDMSR instruction during context switch.
>
> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Originally-by: Tony Luck <tony.luck@intel.com>
> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>

Is it bad form to Ack/Review patches originally by oneself?

Whatever:

Acked-by: Tony Luck <tony.luck@intel.com>

\
 
 \ /
  Last update: 2020-03-21 01:44    [W:0.219 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site