Steven Rostedt <[email protected]> writes: > On Tue, 12 May 2020 23:01:03 +0200 > Thomas Gleixner <[email protected]> wrote: > >> --- a/arch/x86/kernel/cpu/mce/core.c >> +++ b/arch/x86/kernel/cpu/mce/core.c >> @@ -1916,7 +1916,7 @@ static __always_inline void exc_machine_ >> mce_check_crashing_cpu()) >> return; >> >> - nmi_enter(); >> + nmi_enter_notrace(); > > Now a machine check exception could happen and be a cause of latency > (although there may be more issues if it does). The "nmi_enter trace" > version does two things. One is for time measurements (if available), > and the other is just letting the hardware latency know it happen (a > simple increment). > > The only thing that is checked is "smp_processor_id()" (I just > remembered it doesn't need per cpu, as it only runs on a single CPU at > a time). > > Could the notrace version supply the increment, and leave the > trace_clock() in the trace version?
Yes, I can split it up that way.
