Messages in this thread | | | Date | Thu, 25 Feb 2021 15:05:31 -0800 | From | "Paul E. McKenney" <> | Subject | Re: tasks-trace RCU: question about grace period forward progress |
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On Thu, Feb 25, 2021 at 11:23:18PM +0100, Peter Zijlstra wrote: > On Thu, Feb 25, 2021 at 10:33:21AM -0800, Paul E. McKenney wrote: > > One question for Peter... Does each and every context switch imply a > > full barrier? > > Yes, also see the smp_mb__after_spinlock() in __schedule() :-)
Whew!!! ;-)
Yeah, I could make RCU Tasks Trace deal with lack of a full barrier in that case, but I would rather not... I could imagine optimizing so that the full barrier happened only when tasks migrated, but I could also imagine a world of hurt stemming from such an optimization!
Thanx, Paul
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