Running F7 on an Asus A2N-VM motherboard with a built-in RealTek RTL8111/8168B gigabit NIC. When streaming files using Samba to a networked media player the transfer oftens hangs. The client only reads data at a relatively low rate, and that might be part of the reason why the bug is triggered. When transferring data to a laptop computer I get 9.5 MB/s sustained on a 100 Mbit connection, so I don't think there are any problems with the network hardware. The problem occurs with the realtek 8169 driver in the 2.6.22.5-76.fc7 kernel, samba 3.0.26a-0. Same kernel version but another NIC does not show the same behavior. To reproduce it I just need to start playing a song, causing the media player to read a .FLAC file from the samba share. After a while the media player will start dropping out and complaining that the transfer is stopped. netstat -t then shows a large Send-Q for the samba connection. So far only Samba is affected, and doing something else that exercises the network interface (like running wireshark to dump the traffic) makes the problem disappear. Apparently the exact same problem is described in several other places: http://bugzilla.kernel.org/show_bug.cgi?id=7555 https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.22/+bug/114171 http://lists.samba.org/archive/samba/2007-January/128814.html http://lists.samba.org/archive/samba/2006-April/119726.html
Looking further at this, I haven't been able to reproduce the slowdowns with other services than Samba. Oh, and it's Asus M2A, not A2N. Not that it matters a lot :-)
Fixed by Francois Romieu? http://www.mail-archive.com/netdev@vger.kernel.org/msg48351.html http://www.fr.zoreil.com/linux/kernel/2.6.x/2.6.23-rc5/r8169-20070903/0002-r8169-workaround-against-ignored-TxPoll-writes-8168.patch
The link to a kernel bugzilla bug in the original bug here should probably be replaced by http://bugzilla.kernel.org/show_bug.cgi?id=7924 as this one is still open.
Replacing the 2.6.22.x r8169.ko module with one built from the 2.6.23-rc8 source makes the problem disappear, and so far I have experienced no bad side effects.
2.6.22.9 kernel with the two patches is in koji: http://koji.fedoraproject.org/koji/buildinfo?buildID=19726
In 2.6.22.9-91, in updates-testing soon.
I have just tested, and 2.6.22.9-91 fixes the problem - many thanks.