On 2021/03/10 9:29, Shuah Khan wrote: >> It is not a large grain lock. Since event_handler() is exclusively executed, >> this lock >> does _NOT_ block event_handler() unless attach/detach operations run >> concurrently. >> >>> > > event handler queues the events. It shouldn't be blocked by attach > and detach. The events could originate for various reasons during > the host and vhci operations. I don't like using this lock for > attach and detach.
How can attach/detach deadlock event_handler()? event_handler() calls e.g. vhci_shutdown_connection() via ud->eh_ops.shutdown(ud). vhci_shutdown_connection() e.g. waits for termination of tx/rx threads via kthread_stop_put(). event_handler() is already blocked by detach operation. How it can make situation worse to wait for creation of tx/rx threads in attach operation?
