linux_dsm_epyc7002/drivers/net/wan
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
..
lmc PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
.gitignore
c101.c
cosa.c driver/net: cosa driver uses udelay incorrectly 2014-04-15 00:08:22 -04:00
cosa.h
dlci.c net: Pass a "more" indication down into netdev_start_xmit() code paths. 2014-09-01 17:39:55 -07:00
dscc4.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
farsync.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
farsync.h
hd64570.c drivers/net: delete non-required instances of include <linux/init.h> 2014-01-16 11:53:26 -08:00
hd64570.h net: Spelling s/transmition/transmission/ 2014-01-14 17:11:26 -08:00
hd64572.c drivers/net: delete non-required instances of include <linux/init.h> 2014-01-16 11:53:26 -08:00
hd64572.h net: Spelling s/transmition/transmission/ 2014-01-14 17:11:26 -08:00
hdlc_cisco.c
hdlc_fr.c net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
hdlc_ppp.c
hdlc_raw_eth.c
hdlc_raw.c
hdlc_x25.c
hdlc.c net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
hostess_sv11.c net: wan: remove deprecated IRQF_DISABLED 2013-10-07 15:53:52 -04:00
ixp4xx_hss.c
Kconfig
lapbether.c net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
Makefile
n2.c
pc300too.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
pci200syn.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
sbni.c net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
sbni.h
sdla.c net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
sealevel.c net: wan: remove deprecated IRQF_DISABLED 2013-10-07 15:53:52 -04:00
wanxl.c PCI changes for the v3.17 merge window (part 2): 2014-08-14 18:10:33 -06:00
wanxl.h
wanxlfw.inc_shipped
wanxlfw.S
x25_asy.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-07-22 00:44:59 -07:00
x25_asy.h wan: Remove extern from function prototypes 2013-09-24 16:40:19 -07:00
z85230.c
z85230.h wan: Remove extern from function prototypes 2013-09-24 16:40:19 -07:00