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[Bug bpf/25218] stapbpf loses perf_events when writing to interactive terminal


https://sourceware.org/bugzilla/show_bug.cgi?id=25218

Serhei Makarov <me at serhei dot io> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |me at serhei dot io
            Summary|stapbpf losing perf_events  |stapbpf loses perf_events
                   |                            |when writing to interactive
                   |                            |terminal

--- Comment #1 from Serhei Makarov <me at serhei dot io> ---
My suspicion is that the perf_events buffer used to receive transport messages
fills up while the stapbpf process is delayed writing output. This results in
transport messages being overwritten and the 'lost perf_events' warning being
generated.

When stapbpf output is redirected to a file, there is no I/O delay, and
perf_events are consumed before the buffer overflows.

If my suspicion is true, this could be solved by receiving transport messages
in a separate thread.

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