linux/include
Eric Dumazet a4298e4522 net: add SOCK_RCU_FREE socket flag
We want a generic way to insert an RCU grace period before socket
freeing for cases where RCU_SLAB_DESTROY_BY_RCU is adding too
much overhead.

SLAB_DESTROY_BY_RCU strict rules force us to take a reference
on the socket sk_refcnt, and it is a performance problem for UDP
encapsulation, or TCP synflood behavior, as many CPUs might
attempt the atomic operations on a shared sk_refcnt

UDP sockets and TCP listeners can set SOCK_RCU_FREE so that their
lookup can use traditional RCU rules, without refcount changes.
They can set the flag only once hashed and visible by other cpus.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Tested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-04 22:11:19 -04:00
..
acpi Merge branches 'acpi-processor' and 'acpi-cppc' 2016-03-14 14:20:33 +01:00
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 stmmac: add new DT platform entries for GMAC4 2016-04-02 20:23:09 -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 net: add SOCK_RCU_FREE socket flag 2016-04-04 22:11:19 -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 ASoC: Updates for v4.6 2016-03-14 14:03:29 +01:00
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 xen-netback: re-import canonical netif header 2016-03-13 22:08:01 -04:00
Kbuild