On Fri, Jan 9, 2026 at 2:00 PM Steven Rostedt <[email protected]> wrote: > > On Fri, 9 Jan 2026 13:54:34 -0800 > Alexei Starovoitov <[email protected]> wrote: > > > On Fri, Jan 9, 2026 at 12:21 PM Mathieu Desnoyers > > <[email protected]> wrote: > > > > > > > > > * preempt disable/enable pair: 1.1 ns > > > * srcu-fast lock/unlock: 1.5 ns > > > > > > CONFIG_RCU_REF_SCALE_TEST=y > > > * migrate disable/enable pair: 3.0 ns > > > > .. and you're arguing that 3ns vs 1ns difference is so important > > for your out-of-tree tracer that in-tree tracers need to do > > some workarounds?! wtf > > This has nothing to do with out of tree tracers. The overhead of the > 22ns is for any tracepoint in an in-tree module. That's because the > rq->nr_pinned isn't exported for modules to use.
None of the driver's tracepoints are in the critical path. You perfectly know that Mathieu argued about not slowing down lttng.
