On Wed, 2010-09-15 at 09:50 +0800, Xin, Xiaohui wrote: > I think what David said is what we have thought before in mp device. > Since we are not sure the exact time the tx buffer was wrote though > DMA operation. > But the deadline is when the tx buffer was freed. So we only notify > the vhost stuff > about the write when tx buffer freed. But the deadline is maybe too > late for performance. Have you tried it? If so what's the performance penalty you have seen by notifying vhost when tx buffer freed? I am thinking to have a callback in skb destructor, vhost_add_used_and_signal gets updated when skb is actually freed, vhost vq & head need to be passed to the callback. This might requires vhost ring size is at least as big as the lower device driver. Thanks Shirley -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
