Re: [PATCH] Network Checksum Removal

[Bin Ren <bin.ren@gmail.com>]

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.

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)

On 5/23/05, Keir Fraser <Keir.Fraser@cl.cam.ac.uk> wrote:
> 
> On 23 May 2005, at 17:36, Bin Ren wrote:
> 
> > Keir has removed 'SET_ETHTOOL_OPS(dev, &network_ethtool_ops);' from
> > your patch. The operations are not supported.
> 
> Ah, I thought that was just testing infrastructure. I'll take a patch
> to add the ethtool ops back in.
> 
> Bin -- does your domain0 traffic get delivered via the bridge device or
> via the new vif0.0/veth0 that I added? If the former you might want to
> try updating your /etc/xen/scripts/network script. Although delivery
> via the bridge ought to work...
> 
>   -- Keir
> 
> 
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