Re: [RFC] Deadlock via recursive wakeup via RCU with threadirqs

Paul E. McKenney
2019-07-01T12:23:10Z

On Mon, Jul 01, 2019 at 12:24:42PM +0200, Sebastian Andrzej Siewior wrote:
> On 2019-07-01 11:42:15 [+0200], Peter Zijlstra wrote:
> > I'm not sure if smp_send_reschedule() can be used as self-IPI, some
> > hardware doesn't particularly like that IIRC. That is, hardware might
> > only have interfaces to IPI _other_ CPUs, but not self.
> >
> > The normal scheduler code takes care to not call smp_send_reschedule()
> > to self.
>
> and irq_work:
> 471ba0e686cb1 ("irq_work: Do not raise an IPI when queueing work on the local CPU")

OK, so it looks like I will need to use something else. But thank you
for calling my attention to this commit.

Thanx, Paul