Re: [3.15-rc3] Bisected: xen-netback mangles packets between two guests on a bridge since merge of "TX grant mapping with SKBTX_DEV_ZEROCOPY instead of copy" series.
From: Neal Cardwell <ncardwell@google.com>
Date: 2014-05-09 22:19:10
On Fri, May 2, 2014 at 11:35 AM, Eric Dumazet [off-list ref] wrote:
On Thu, 2014-05-01 at 17:40 +0200, Sander Eikelenboom wrote:quoted
Yesterday i tried to get packetdrill (https://code.google.com/p/packetdrill/) to work to see if i could reproduce with one of it's tests, but didn't get the client server stuff working. It seems it has helped with finding and fixing previous kernel networking bugs.If you use recent net-next kernel, you need a packetdrill patch, Neal might submit it shortly on packetdrill repo. packetdrill currently does not consume the packets sent on the tun device, so this triggers the new [1] TCP stack behavior detecting packet did not yet leaved the host. [1] : ( http://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id=1f3279ae0c13cd742731726b0ed195d5f09b14e4 )
I have submitted the fix to the packetdrill repo. If you "git pull" the latest packetdrill sources then its "local mode" should work again for net-next. Sorry if the delay has caused any hassles. neal