On Tue, 13 Dec 2016, Peter Zijlstra wrote:
> 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.
That means to increase all CPUs in the package of the other CPU by that
amount ....
> But yes, yuck.
Indeed.
tglx
