Comment by jerrinot
1 day ago
That's a brilliant trick. The setup overhead and permission requirements for perf_event might be heavy for arbitrary threads, but for long-lived threads it looks pretty awesome! Thanks for sharing!
1 day ago
That's a brilliant trick. The setup overhead and permission requirements for perf_event might be heavy for arbitrary threads, but for long-lived threads it looks pretty awesome! Thanks for sharing!
Yes you need some lazy setup in thread-local state to use this. And short-lived threads should be avoided anyway :)
I guess if you need the concurrency/throughput you should use a userspace green thread implementation. I’m guessing most implementations of green threads multiplex onto long running os threads anyway
In a system with green threads, you typically want the CPU time of the fiber or tasklet rather than the carrier thread. In that case, you have to ask the scheduler, not the kernel.