leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

net: revert 8728c544a9 ("net: dev_pick_tx() fix")

Browse Source 
commit 8728c544a9 ("net: dev_pick_tx() fix") and commit
b6fe83e952 ("bonding: refine IFF_XMIT_DST_RELEASE capability")
are quite incompatible : Queue selection is disabled because skb
dst was dropped before entering bonding device.

This causes major performance regression, mainly because TCP packets
for a given flow can be sent to multiple queues.

This is particularly visible when using the new FQ packet scheduler
with MQ + FQ setup on the slaves.

We can safely revert the first commit now that 416186fbf8
("net: Split core bits of netdev_pick_tx into __netdev_pick_tx")
properly caps the queue_index.

Reported-by: Xi Wang <xii@google.com>
Diagnosed-by: Xi Wang <xii@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Denys Fedorysychenko <nuclearcat@nuclearcat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2013-08-28 18:10:43 -07:00 committed by David S. Miller
parent 25ad6117e7
commit 702821f4ea
1 changed files with 3 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
net/core/flow_dissector.c
View File

@ -346,14 +346,9 @@ u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb)
if (new_index < 0)
new_index = skb_tx_hash(dev, skb);
if (queue_index != new_index && sk) {
struct dst_entry *dst =
rcu_dereference_check(sk->sk_dst_cache, 1);
if (dst && skb_dst(skb) == dst)
sk_tx_queue_set(sk, queue_index);
}
if (queue_index != new_index && sk &&
rcu_access_pointer(sk->sk_dst_cache))
sk_tx_queue_set(sk, queue_index);
queue_index = new_index;
}