Messages in this thread | | | Date | Wed, 12 Feb 2020 16:02:11 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 4/8] sched,rcu,tracing: Mark preempt_count_{add,sub}() notrace |
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On Wed, Feb 12, 2020 at 09:24:17AM -0500, Steven Rostedt wrote: > On Wed, 12 Feb 2020 10:32:14 +0100 > Peter Zijlstra <peterz@infradead.org> wrote: > > > Because of the requirement that no tracing happens until after we've > > incremented preempt_count, see nmi_enter() / trace_rcu_enter(), mark > > these functions as notrace. > > I actually depend on these function being traced.
Why? They already have a tracepoint inside.
> We do have > "preempt_enable_notrace()" and "preempt_disable_notrace()" for places > that shouldn't be traced. Can't we use those? (or simply > __preempt_count_add()) in the nmi_enter() code instead? (perhaps create > a preempt_count_add_notrace()).
My initial patch has __preempt_count_add/sub() in, but then I figured someone would go complain the tracepoint would go missing.
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