On Fri, 28 Sep 2018, Sebastian Andrzej Siewior wrote:
> On 2018-09-27 16:47:47 [+0200], Thomas Gleixner wrote:
> > I wonder if it's just the store on the stack which makes it work. I've seen
> > that when instrumenting x86. When the careful instrumentation just stayed
> > in registers it failed. Once it was too much and stack got involved it
> > vanished away.
>
> Added two load/stores into wait_task_inactive() and it still triggers
> (on the core2duo).
So it was some interaction with rdtsc() which got stored on
stack. Heisenbugs are lovely.
Thanks,
tglx
