linux/net/atm
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
..
addr.c
addr.h
atm_misc.c atm: eliminate atm_guess_pdu2truesize() 2011-11-26 16:40:30 -05:00
atm_sysfs.c atm: use scnprintf() instead of sprintf() 2012-12-17 20:50:51 -08:00
br2684.c net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
clip.c net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
common.c atm: Convert pr_warning to pr_warn 2014-09-10 12:40:10 -07:00
common.h atm: Introduce vcc_process_recv_queue 2011-11-22 16:15:42 -05:00
ioctl.c net: Convert net_ratelimit uses to net_<level>_ratelimited 2012-05-15 13:45:03 -04:00
Kconfig
lec_arpc.h
lec.c lec: Use rtnl lock/unlock when updating MTU 2014-08-21 16:31:23 -07:00
lec.h net: add ETH_P_802_3_MIN 2013-03-28 01:20:42 -04:00
Makefile
mpc.c net: Pass a "more" indication down into netdev_start_xmit() code paths. 2014-09-01 17:39:55 -07:00
mpc.h
mpoa_caches.c
mpoa_caches.h
mpoa_proc.c net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
pppoatm.c arch: Mass conversion of smp_mb__*() 2014-04-18 14:20:48 +02:00
proc.c procfs: new helper - PDE_DATA(inode) 2013-04-09 14:13:32 -04:00
protocols.h
pvc.c atm: fix info leak via getsockname() 2012-08-15 21:36:30 -07:00
raw.c net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
resources.c net🏧fix up ENOIOCTLCMD error handling 2012-08-31 16:14:33 -04:00
resources.h atm: correct sysfs 'device' link creation and parent relationships 2010-12-10 15:45:05 -08:00
signaling.c net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
signaling.h
svc.c atm/svc: Fix blocking in wait loop 2014-08-13 20:04:46 -07:00