scxtop: fixing missing process names #1694
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hodgesds
reviewed
Apr 17, 2025
| @@ -248,6 +249,12 @@ impl PerfettoTraceManager { | |||
| } | |||
| } | |||
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| fn get_comm(pid: i32) -> Result<String> { | |||
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nit: there's already a helper function for reading files.
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Thanks @hodgesds for pointing this out! I'll try and refactor some time to use that interface.
hodgesds
approved these changes
Apr 17, 2025
hodgesds
approved these changes
Apr 17, 2025
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We now have process -> thread relationships setup so the grouping are good. However, for longer running processes it is quite common for the main thread to not run at all while we are tracing and this means we never get to capture its comm. This makes it hard to identify the process to which a bunch of threads belong as any
ProcessDescriptorsobjects which have theprocess_nameOption unset causes the process thread (the thread group leader) to be labelled as "Process" in the resulting perfetto trace.The solution here is to simply go lookup the
commvalue in/procif it exists when scxtop exits. I'm not worried about pid reuse as trace times are too short for it to be a problem.An example of before the changes shows the current state with lots of processes being labelled with the default label:
Now virtually every process is labeled correctly (at least on my development machine).