On Mon, 24 Feb 2020 22:31:39 +0100 Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > Just want to confirm that printk_nmi_enter(), lockdep_off(), > > and ftrace_nmi_enter() are all marked fully with NOKPROBE. > > *sigh*, right you are, I only looked at notrace, not nokprobe. > > In particular the ftrace one is a bit off a mess, let me sort through > that. ftrace_nmi_enter() has two purposes. One, for archs that need to deal with NMIs while they still use stop machine. Although, it appears sh is the only arch that does that. I can look to see if it can be ripped out. The other is for the hwlat detector that measures the time it was in an NMI, as NMIs appear as a hardware latency too. -- Steve
