diff options
| author | Eric Dumazet <edumazet@google.com> | 2014-10-05 18:38:35 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-10-07 13:22:11 -0400 |
| commit | 0287587884b15041203b3a362d485e1ab1f24445 (patch) | |
| tree | 675ae57663c1ba3ee8768e65e7fb0e6d0259e04c /drivers/s390 | |
| parent | fe971b95c22578456ff7198537827841c726d3f7 (diff) | |
| download | linux-0287587884b15041203b3a362d485e1ab1f24445.tar.bz2 | |
net: better IFF_XMIT_DST_RELEASE support
Testing xmit_more support with netperf and connected UDP sockets,
I found strange dst refcount false sharing.
Current handling of IFF_XMIT_DST_RELEASE is not optimal.
Dropping dst in validate_xmit_skb() is certainly too late in case
packet was queued by cpu X but dequeued by cpu Y
The logical point to take care of drop/force is in __dev_queue_xmit()
before even taking qdisc lock.
As Julian Anastasov pointed out, need for skb_dst() might come from some
packet schedulers or classifiers.
This patch adds new helper to cleanly express needs of various drivers
or qdiscs/classifiers.
Drivers that need skb_dst() in their ndo_start_xmit() should call
following helper in their setup instead of the prior :
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
->
netif_keep_dst(dev);
Instead of using a single bit, we use two bits, one being
eventually rebuilt in bonding/team drivers.
The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being
rebuilt in bonding/team. Eventually, we could add something
smarter later.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/net/qeth_l3_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index f8427a2c4840..afebb9709763 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -3306,7 +3306,7 @@ static int qeth_l3_setup_netdev(struct qeth_card *card) card->dev->features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_CTAG_FILTER; - card->dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; + netif_keep_dst(card->dev); card->dev->gso_max_size = 15 * PAGE_SIZE; SET_NETDEV_DEV(card->dev, &card->gdev->dev); |