twx-linux/include
Eric Dumazet 3b24d854cb tcp/dccp: do not touch listener sk_refcnt under synflood
When a SYNFLOOD targets a non SO_REUSEPORT listener, multiple
cpus contend on sk->sk_refcnt and sk->sk_wmem_alloc changes.

By letting listeners use SOCK_RCU_FREE infrastructure,
we can relax TCP_LISTEN lookup rules and avoid touching sk_refcnt

Note that we still use SLAB_DESTROY_BY_RCU rules for other sockets,
only listeners are impacted by this change.

Peak performance under SYNFLOOD is increased by ~33% :

On my test machine, I could process 3.2 Mpps instead of 2.4 Mpps

Most consuming functions are now skb_set_owner_w() and sock_wfree()
contending on sk->sk_wmem_alloc when cooking SYNACK and freeing them.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-04 22:11:20 -04:00
..
acpi
asm-generic arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-03-17 11:33:45 -07:00
drm Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2016-03-21 13:48:00 -07:00
dt-bindings The clk changes for this release cycle are mostly dominated by 2016-03-23 06:06:45 -07:00
keys
kvm
linux udp: no longer use SLAB_DESTROY_BY_RCU 2016-04-04 22:11:19 -04:00
math-emu
media Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2016-03-19 16:31:54 -07:00
memory
misc
net tcp/dccp: do not touch listener sk_refcnt under synflood 2016-04-04 22:11:20 -04:00
pcmcia
ras
rdma Round two of 4.6 merge window patches 2016-03-22 15:48:44 -07:00
rxrpc
scsi SCSI misc on 20160326 2016-03-26 11:31:01 -07:00
soc IOMMU Updates for Linux v4.6 2016-03-22 11:57:43 -07:00
sound
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-03-22 12:41:14 -07:00
trace mm/page_isolation: fix tracepoint to mirror check function behavior 2016-04-01 17:03:37 -05:00
uapi sock: accept SO_TIMESTAMPING flags in socket cmsg 2016-04-04 15:50:30 -04:00
video
xen
Kbuild