linux_dsm_epyc7002/include
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
..
acpi Merge branches 'acpi-hotplug', 'acpi-scan', 'acpi-lpss', 'acpi-gpio' and 'acpi-video' 2014-09-25 22:59:30 +02:00
asm-generic This is the bulk of GPIO changes for the v3.17 development 2014-08-08 18:00:35 -07:00
clocksource
crypto crypto: drbg - backport "fix maximum value checks on 32 bit systems" 2014-09-05 15:52:28 +08:00
drm drm/radeon: add additional SI pci ids 2014-08-22 10:47:59 -04:00
dt-bindings Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-08-11 07:14:01 -07:00
keys
kvm
linux net: better IFF_XMIT_DST_RELEASE support 2014-10-07 13:22:11 -04:00
math-emu
media [media] vb2: fix VBI/poll regression 2014-09-21 20:57:30 -03:00
memory
misc
net openvswitch: fix a compilation error when CONFIG_INET is not setW! 2014-10-07 00:10:49 -04:00
pcmcia
ras
rdma IB: ib_umem_release() should decrement mm->pinned_vm from ib_umem_get 2014-09-19 09:55:42 -07:00
rxrpc include/rxrpc/types.h: Remove unused header 2014-08-29 20:33:39 -07:00
scsi [SCSI] fix regression that accidentally disabled block-based tcq 2014-09-19 13:23:32 +01:00
soc/tegra
sound ASoC: core: fix .info for SND_SOC_BYTES_TLV 2014-08-18 08:59:12 -05:00
target
trace net: treewide: Fix typo found in DocBook/networking.xml 2014-09-05 17:35:28 -07:00
uapi ethtool: Ethtool parameter to dynamically change tx_copybreak 2014-10-06 01:04:16 -04:00
video fbdev changes for 3.17 2014-08-08 18:09:33 -07:00
xen xen/arm: introduce XENFEAT_grant_map_identity 2014-09-11 18:11:52 +00:00
Kbuild