On Thu, 2011-02-03 at 18:20 +0200, Michael S. Tsirkin wrote: > Just a thought: does it help to make tx queue len of the > virtio device smaller?
Yes, that what I did before, reducing txqueuelen will cause qdisc dropp the packet early, But it's hard to control by using tx queuelen for performance gain. I tried on different systems, it required different values. Also, I tried another patch, instead of dropping packets, I used to timer (2 jiffies) to enable/disable queue on guest without interrupts notification, it gets better performance than original but worse performance than dropping packets because of netif stop/wake up too often. vhost is definitely needed to improve for handling small message sizes. It's unable to handle small message packets rate for queue size 256, even with ring size 1024. QEMU seems not allowing to increase the TX ring size to 2K (start qemu_kvm failure with no errors), I am not able to test it out. Thanks Shirley -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
