patacongo commented on PR #14578: URL: https://github.com/apache/nuttx/pull/14578#issuecomment-2501657197
The spinlock has always been a very light weight way of waiting. In SMP, sched_lock() is heavy weight and and also calls enter_critical_section which is even heavier. This will effect performance. General mutual exclusion is not required. All that is required is that the waiting thread no be suspended. You should consider a redesign to keep this as lightweight as possible. Consider this: - Since general mutual exclusion, is not required. It is not necessary to interact with the other CPUs at all - A single bit of information in the TCB will do the job. If the thread is waiting for a spinlock, that bit is set and, in that case the thread is never suspended. The bit is cleared after the spinlock is acquired. This is a very simple change, similar to sched_lock() in non-SMP mode. And would return the spinlock as a simple efficient interface. This would only affect the spinlock and scheduler. With would not affect other cpus or releases the spinlock. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@nuttx.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
