On Wed, 6 Nov 2002, Ben Greear wrote:
>
> Here's an update of the tulip-NAPI and skb-recycle patches. I made some
> changes to get it to compile and work when the RECYCLE define in skbuff.h
> was not enabled.
>
> I also got some test runs in. Nothing really conclusive.
>
> Test setup: Phobos 4-port NIC in each P-IV 1.8Ghz machine 32/33 PCI bus.
> Kernel 2.4.20-rc1 + my patches. NICs connected to each other over CX cables.
> Sending 4k 1514 byte packets per second, send + receive. (48Mbps or so)
> RX ring size is 1024 for all of these tests. No significant errors reported
> by the driver. I don't know where these dropped packets go..no counter
> seems to be catching them.
>
> I sent 1 million packets (or very close to that) on every interface (received
> the same, mostly)
>
> Without SKB-Recycle:
> dropped 339 out of 1Million, repeated test twice, numbers very similar.
> When packets do drop, they drop on all interfaces in bursts of 10-150,
> generally.
> Latency was about .3ms
>
> With SKB-Recycle (300 pkt hot-list)
> dropped 230, 500, and 180 in consecutive runs. They also drop in bursts.
> The middle run may be bad luck...don't know.
> Latency was about .3ms
> While typing, I ran a longer test. Dropped about 1600 out of 4 million.
>
Trash the machines harder. Try using smaller packets;
cheers,
jamal
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