Messages in this thread | | | From | Jiri Olsa <> | Date | Mon, 15 Aug 2022 11:44:32 +0200 | Subject | Re: [RFC] ftrace: Add support to keep some functions out of ftrace |
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On Mon, Aug 15, 2022 at 10:03:17AM +0200, Peter Zijlstra wrote: > On Sat, Aug 13, 2022 at 03:02:52PM -0400, Steven Rostedt wrote: > > On Fri, 12 Aug 2022 23:18:15 +0200 > > Jiri Olsa <olsajiri@gmail.com> wrote: > > > > > the patch below moves the bpf function into sepatate object and switches > > > off the -mrecord-mcount for it.. so the function gets profile call > > > generated but it's not visible to ftrace > > Why ?!?
there's bpf dispatcher code that updates bpf_dispatcher_xdp_func function with bpf_arch_text_poke and that can race with ftrace update if the function is traced
the idea to solve it is to 'mark' the function independent of ftrace, and add a way to make the function invissible to ftrace but with the profile code fentry call generated
jirka
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