On 08/06, Gregory Haskins wrote: > > On Mon, 2007-08-06 at 18:45 +0400, Oleg Nesterov wrote: > > On 08/06, Peter Zijlstra wrote: > > > > > > > still this does not change the fundamental issue of a high prio piece of > > > work waiting on a lower prio task. > > ^^^^^^^ > > waiting. This is a "key" word, and this was my (perhaps wrong) point. > > Actually, I think Peter is making a really important point here. Yes. Please see another email I just sent. > "Waiting" can be defined in more ways than the REQUEST/RESPONSE pattern > that I have been rambling about. > > Using Peters NIC vs USB example: What if a NIC driver is using a > workqueue as a bottom-half mechanism for its RX packet queuing. In a > nice RT environment it would be highly ideal if we allow the deferred > work to complete with respect to the priority that was assigned to the > subsystem. > > So while the submitter isn't technically blocking on the work, the > application that is receiving packets is now subject to the arbitrary > priority of the keventd as opposed to the NIC irq. Thus there is still > "waiting" being subject to inversion, its just not in a REQUEST/RESPONSE > pattern. Oleg. - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
