[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH] Network Checksum Removal

Bin Ren wrote:
I've added the support for ethtools. By turning on and off netfront
checksum offloading, I'm getting the following throughput numbers,
using iperf. Each test was run three times. CPU usages are quite
similar in two cases ('top' output). Looks like checksum computation
is not a major overhead in domU networking.

dom0/1/2 all have 128M memory. dom0 has e1000 tx checksum offloading turned on.

Yeah, if you want to do anything network intensive, 128MB is just
not enough - you really need more memory in your system.

With Tx checksum on:

dom1->dom2: 300Mb/s (dom0 cpu maxed out by software interrupts)
dom1->dom0: 459Mb/s (dom0 cpu 80% in SI, dom1 cpu 20% in SI)
dom1->external: 439Mb/s (over 1Gb/s ethernet) (dom0 cpu 50% in SI,
dom1 60% in SI)

With Tx checksum off:

dom1->dom2: 301Mb/s
dom1->dom0: 454Mb/s
dom1->externel: 437Mb/s (over 1Gb/s ethernet)

iperf is a directional send test, correct?
i.e. is dom1 -> dom0 perf the same as dom0 -> dom1 for you?


Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.