On Thu, 18 Oct 2018 17:19:32 -0700 "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx> wrote: > I figured that whoever calls preempt_enable_no_resched() is taking the > responsibility for permitting preemption in the near future, and if they > fail to do so, they will get called on it. Hard to hide from the latency > tracer, after all. ;-) Correct, and doing a search of preempt_enable_no_resched() I see there's one in the ftrace ring buffer code, that was added a long time ago (2008) to fix a recursion bug that no longer exists, and this now can leak a preemption point. I'll have to go fix that :-( -- Steve
