On Thu, Oct 18, 2018 at 09:12:45PM -0400, Steven Rostedt wrote: > 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 :-( Cool! Glad you found this issue in the code while we are discussing it ;) thanks, - Joel
