> -----Original Message----- > From: Sitsofe Wheeler [mailto:sits...@gmail.com] > Sent: Tuesday, August 19, 2014 8:37 AM > To: KY Srinivasan > Cc: Greg Kroah-Hartman; Haiyang Zhang; de...@linuxdriverproject.org; > linux-kernel@vger.kernel.org; Jason Wang; Daniel Borkmann; David S. > Miller; net...@vger.kernel.org > Subject: [hyperv] BUG at drivers/hv/channel.c:462 while changing MTU > > Now we get to the issue I've been meaning to report: changing the MTU of > a Hyper-V network interface while traffic is flowing through it triggers > a BUG. I've seen this happen on a variety of kernels but the trace below > is from 3.17.0-rc1. > > Steps to reproduce: > (Guests were customised Fedora 20 cloud images) > 1.On Hyper-V VM 1 run > iperf -s > 2. On Hyper-V VM 2 run > iperf -c <Hyper-V VM 1 host address> -t 200 > 3. On Hyper-V VM 2 run > ip link set dev eth0 mtu 9000 > > Expected results: > MTU of eth0 to be changed, packets to keep flowing or stop, interface to > be at alive enough to be reconfigured. > > Actual results: > Error messages on the console, eth0 winds up dead. >
Thanks for the report. I tried changing mtu while iperf is running, but unable to reproduce it. I repeated the changing MTU test 10+ times, the link is stable, and passing traffic at ~8Gbps. Could you try a Distro without customization? I just want to narrow down the possible causes for it. Thanks, - Haiyang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
