On Tue, Dec 27, 2022 at 12:30:35PM +0800, Jason Wang wrote: > > But device is still going and will later use the buffers. > > > > Same for timeout really. > > Avoiding infinite wait/poll is one of the goals, another is to sleep. > If we think the timeout is hard, we can start from the wait. > > Thanks If the goal is to avoid disrupting traffic while CVQ is in use, that sounds more reasonable. E.g. someone is turning on promisc, a spike in CPU usage might be unwelcome. things we should be careful to address then: 1- debugging. Currently it's easy to see a warning if CPU is stuck in a loop for a while, and we also get a backtrace. E.g. with this - how do we know who has the RTNL? We need to integrate with kernel/watchdog.c for good results and to make sure policy is consistent. 2- overhead. In a very common scenario when device is in hypervisor, programming timers etc has a very high overhead, at bootup lots of CVQ commands are run and slowing boot down is not nice. let's poll for a bit before waiting? 3- suprise removal. need to wake up thread in some way. what about other cases of device breakage - is there a chance this introduces new bugs around that? at least enumerate them please. -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
