scx_rustland: notify user-space scheduler about exiting tasks #61
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Instead of implementing a garbage collector to periodically free up exiting tasks' resources, implement a proper synchronous mechanism to notify the user-space scheduler about the exiting tasks from the BPF component, using the .disable() callback. When the user-space scheduler receives a queued task with a negative CPU number, it can then release all the resources associated with that task (which currently includes only the entry in the TaskInfoMap for now). This allows to get rid of the TaskInfoMap periodic garbage collector routine, save a lot of syscalls in procfs (used to check if the pids were still alive), and improve the overall scheduler performance. Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
htejun
approved these changes
Jan 2, 2024
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Instead of implementing a garbage collector to periodically free up exiting tasks' resources, implement a proper synchronous mechanism to notify the user-space scheduler about the exiting tasks from the BPF component, using the .disable() callback.
When the user-space scheduler receives a queued task with a negative CPU number, it can then release all the resources associated with that task (which currently includes only the entry in the TaskInfoMap for now).
This allows to get rid of the TaskInfoMap periodic garbage collector routine, save a lot of syscalls in procfs (used to check if the pids were still alive), and improve the overall scheduler performance.