linux/net
Eric Dumazet 0287587884 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>
2014-10-07 13:22:11 -04:00
..
6lowpan 6lowpan: Allow 6LoWPAN to be modular 2014-08-07 11:44:18 -07:00
9p 9P: remove unnecessary break after return 2014-07-15 16:27:00 -07:00
802 net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
8021q net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
appletalk Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-07-16 14:09:34 -07:00
atm net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
ax25
batman-adv batman-adv: Fix parameter order of hlist_add_behind 2014-08-16 19:19:08 -07:00
bluetooth Bluetooth: 6lowpan: Check transmit errors for multicast packets 2014-10-02 13:41:57 +03:00
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2014-10-05 21:32:37 -04:00
caif caif: remove unnecessary break after goto 2014-07-15 16:27:01 -07:00
can
ceph libceph: do not hard code max auth ticket len 2014-09-10 20:08:36 +04:00
core net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
dcb dcbnl : Fix misleading dcb_app->priority explanation 2014-07-30 17:21:05 -07:00
dccp net/dccp/ccid.c: add __init to ccid_activate 2014-10-01 18:33:13 -04:00
decnet af_decnet: Use time_after_eq 2014-08-22 12:23:11 -07:00
dns_resolver Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2014-08-06 08:06:39 -07:00
dsa net: dsa: do not call phy_start_aneg 2014-10-04 20:44:44 -04:00
ethernet net: Add function for parsing the header length out of linear ethernet frames 2014-09-05 17:47:02 -07:00
hsr net/hsr: Remove left-over never-true conditional code. 2014-07-11 15:04:40 -07:00
ieee802154 Merge tag 'master-2014-10-02' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next 2014-10-05 21:34:39 -04:00
ipv4 net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
ipv6 net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
ipx
irda irda: add __init to irlan_open 2014-09-30 17:08:06 -04:00
iucv iucv: Convert pr_warning to pr_warn 2014-09-10 12:40:10 -07:00
key af_key: remove unnecessary break after return 2014-07-15 16:27:00 -07:00
l2tp l2tp: Refactor l2tp core driver to make use of the common UDP tunnel functions 2014-09-19 15:57:15 -04:00
lapb
llc
mac80211 Merge tag 'master-2014-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next 2014-09-26 15:39:24 -04:00
mac802154 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2014-09-08 11:14:56 -04:00
mpls net: Remove gso_send_check as an offload callback 2014-09-26 00:22:47 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2014-10-05 21:32:37 -04:00
netlabel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-08-06 09:38:14 -07:00
netlink netlink: Annotate RCU locking for seq_file walker 2014-08-14 15:13:40 -07:00
netrom net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
nfc NFC: nci: Add support for proprietary RF Protocols 2014-09-24 02:02:24 +02:00
openvswitch openvswitch: fix a sparse warning 2014-10-07 00:10:48 -04:00
packet net: Pass a "more" indication down into netdev_start_xmit() code paths. 2014-09-01 17:39:55 -07:00
phonet net: fix rcu access on phonet_routes 2014-10-06 18:16:30 -04:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-06-12 14:27:40 -07:00
rfkill net: rfkill: gpio: Fix clock status 2014-09-22 16:02:15 -04:00
rose rose: use %*ph specifier 2014-09-07 16:07:25 -07:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-09-23 12:09:27 -04:00
sched net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
sctp net/ipv4: bind ip_nonlocal_bind to current netns 2014-09-09 11:27:09 -07:00
sunrpc NFS client updates for Linux 3.17 2014-08-13 18:13:19 -06:00
tipc tipc: fix sparse warnings 2014-09-10 14:00:58 -07:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-06-12 14:27:40 -07:00
vmw_vsock
wimax
wireless Merge tag 'master-2014-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next 2014-09-26 15:39:24 -04:00
x25
xfrm net: cleanup and document skb fclone layout 2014-10-01 16:34:25 -04:00
compat.c net: sendmsg: fix NULL pointer dereference 2014-07-29 12:20:22 -07:00
Kconfig netfilter: bridge: build br_nf_core only if required 2014-09-30 14:07:51 -04:00
Makefile 6lowpan: introduce new net/6lowpan directory 2014-07-12 01:53:30 +02:00
nonet.c
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-09-23 12:09:27 -04:00
sysctl_net.c