On Tue, Dec 24, 2019 at 10:56:08AM +0000, Roman Kagan wrote: > I'm trying to get my head around how the flow control in vmbus ring > buffers works. > > In particular, I'm failing to see how the following can be prevented: > > > producer | consumer > ================================================================== > read read_index | > (enough room for packet) | > write pending_send_sz = 0 | > write packet | > update write_index | > | read write_index > read read_index | read packet > (not enough room for packet) | update read_index (= write_index) > | read pending_send_sz = 0 > write pending_send_sz = X | skip notification > go to sleep | go to sleep > stall > > Could anybody please shed some light on how it's supposed to work? Sorry to reply to myself, but looks like the answer is to re-read read_index on the producer side after setting pending_send_sz. Thanks and sorry for the noise, Roman.
