lkml.org 
[lkml]   [2016]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [patch 2/2] x86/tsc: Force TSC_ADJUST register to value >= zero
On Tue, Dec 13, 2016 at 01:14:17PM -0000, Thomas Gleixner wrote:
> @@ -429,8 +447,13 @@ void check_tsc_sync_target(void)
> * that the warp is not longer detectable when the observed warp
> * value is used. In the worst case the adjustment needs to go
> * through a 3rd run for fine tuning.
> + *
> + * But we must make sure that the value doesn't become negative
> + * otherwise TSC deadline timer will create an interrupt storm.
> */
> cur->adjusted += cur_max_warp;
> + if (cur->adjusted < 0)
> + cur->adjusted = 0;
>

So depending on how horrid we want to make this we could work around
this by increasing the ADJUST of the other CPUs by the amount we're
negative.

But yes, yuck.

\
 
 \ /
  Last update: 2016-12-13 14:44    [W:0.170 / U:0.184 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site