On Thu, Feb 03, 2011 at 07:58:00AM -0800, Shirley Ma wrote: > On Thu, 2011-02-03 at 08:13 +0200, Michael S. Tsirkin wrote: > > > Initial TCP_STREAM performance results I got for guest to local > > host > > > 4.2Gb/s for 1K message size, (vs. 2.5Gb/s) > > > 6.2Gb/s for 2K message size, and (vs. 3.8Gb/s) > > > 9.8Gb/s for 4K message size. (vs.5.xGb/s) > > > > What is the average packet size, # bytes per ack, and the # of > > interrupts > > per packet? It could be that just slowing down trahsmission > > makes GSO work better. > > There is no TX interrupts with dropping packet. > > GSO/TSO is the key for small message performance, w/o GSO/TSO, the > performance is limited to about 2Gb/s no matter how big the message size > it is. I think any work we try here will increase large packet size > rate. BTW for dropping packet, TCP increased fast retrans, not slow > start. > > I will collect tcpdump, netstart before and after data to compare packet > size/rate w/o w/i the patch. > > Thanks > Shirley Just a thought: does it help to make tx queue len of the virtio device smaller? E.g. match the vq size? -- MST -- 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
