After some discussion in upstream maillist, looks the problem is caused
by below commit:
commit a9e0aca4b37885b5599e52211f098bd7f565e749
Author: Eric Dumazet <eric.duma...@gmail.com>
Date: Wed Mar 14 20:18:32 2012 +0000
asix: asix_rx_fixup surgery to reduce skb truesizes
asix_rx_fixup() is complex, and does some unnecessary memory copies (at
least on x86 where NET_IP_ALIGN is 0)
Also, it tends to provide skbs with a big truesize (4096+256 with
MTU=1500) to upper stack, so incoming trafic consume a lot of memory and
I noticed early packet drops because we hit socket rcvbuf too fast.
Switch to a different strategy, using copybreak so that we provide nice
skbs to upper stack (including the NET_SKB_PAD to avoid future head
reallocations in some paths)
With this patch, I no longer see packets drops or tcp collapses on
various tcp workload with a AX88772 adapter.
so I built kernel image with the patch, anyone can have a test?
http://kernel.ubuntu.com/~ming/bugs/947723/i386/2/
thanks
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/947723
Title:
ASIX USB-Ethernet driver noticably slow, dropping packets and
reporting RX errors
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/947723/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
