On Wed, May 29, 2019 at 03:19:57PM +0200, Peter Zijlstra wrote: > On Wed, May 29, 2019 at 08:39:30AM -0400, Steven Rostedt wrote: > > I believe I see what Daniel is talking about, but I hate the proposed > > solution ;-) > > > > First, if you care about real times that the CPU can't preempt > > (preempt_count != 0 or interrupts disabled), then you want the > > preempt_irqsoff tracer. The preempt_tracer is more academic where it > > just shows you when we disable preemption via the counter. But even > > with the preempt_irqsoff tracer you may not get the full length of time > > due to the above explained race. > > IOW, that tracer gives a completely 'make believe' number? What's the > point? Just delete the pure preempt tracer.
Alternatively, fix the preempt tracer by having it completely disregard IRQs.
