** Changed in: linux (Ubuntu Utopic)
Status: Fix Committed => Fix Released
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1390604
Title:
Outbound TCP Throughput drops to zero for several drivers
Status in linux package in Ubuntu:
Fix Released
Status in linux source package in Utopic:
Fix Released
Status in linux source package in Vivid:
Fix Released
Bug description:
There is a bug with TCP in kernel 3.16+ described as:
"Some drivers are unable to perform TX completions in a bound time.
They instead call skb_orphan()
Problem is skb_fclone_busy() has to detect this case, otherwise
we block TCP retransmits and can freeze unlucky tcp sessions on
mostly idle hosts."
A patch for this has been submitted upstream:
https://patchwork.ozlabs.org/patch/405110/
The Google engineer that submitted that patch also adds the following:
Backported patch for 3.16 or 3.17 kernel is much simpler :
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 4e4932b5079b..a8794367cd20 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2082,7 +2082,8 @@ static bool skb_still_in_host_queue(const struct sock
*sk,
const struct sk_buff *fclone = skb + 1;
if (unlikely(skb->fclone == SKB_FCLONE_ORIG &&
- fclone->fclone == SKB_FCLONE_CLONE)) {
+ fclone->fclone == SKB_FCLONE_CLONE &&
+ fclone->sk == sk)) {
NET_INC_STATS_BH(sock_net(sk),
LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES);
return true;
I do not believe that this problem affects any release prior to 14.10, and I
don't know which version of the patch you may need, but have included both.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1390604/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
