Messages in this thread | | | Date | Sat, 30 Jan 2016 16:28:25 -0800 | From | "Paul E. McKenney" <> | Subject | Re: timers: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected |
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On Fri, Jan 29, 2016 at 04:27:35PM +0100, Peter Zijlstra wrote: > On Fri, Jan 15, 2016 at 03:14:10PM -0800, Paul E. McKenney wrote: > > And if I make the scheduling-clock interrupt send extra wakeups to the RCU > > grace-period kthread when needed, things work even with CPU hotplug going. > > > > The "when needed" means any time that the RCU grace-period kthread has > > been sleeping three times as long as the timeout interval. If the first > > wakeup does nothing, it does another wakeup once per second. > > > > So it looks like this change makes an existing problem much worse, as > > opposed to introducing a new problem. > > I have a vague idea about a possible race window. Have you been > observing this on PPC or x86? > > The reason I'm asking is that PPC (obviously) allows for more races :-)
;-)
I have been seeing this on x86.
Thanx, Paul
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