On Thu, 18 Feb 2021 17:21:19 -0500 Michael Jeanson <mjeanson@xxxxxxxxxxxx> 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
