Messages in this thread | | | Date | Tue, 23 Feb 2021 21:16:39 -0500 | From | Steven Rostedt <> | Subject | Re: [RFC PATCH 0/6] [RFC] Faultable tracepoints (v2) |
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On Thu, 18 Feb 2021 17:21:19 -0500 Michael Jeanson <mjeanson@efficios.com> wrote:
> This series only implements the tracepoint infrastructure required to > allow tracers to handle page faults. Modifying each tracer to handle > those page faults would be a next step after we all agree on this piece > of instrumentation infrastructure.
I started taking a quick look at this, and came up with the question: how do you allow preemption when dealing with per-cpu buffers or storage to record the data?
That is, perf, bpf and ftrace are all using some kind of per-cpu data, and this is the reason for the need to disable preemption. What's the solution that LTTng is using for this? I know it has a per cpu buffers too, but does it have some kind of "per task" buffer that is being used to extract the data that can fault?
-- Steve
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