Eric Dumazet ad52eef552 inetpeer: get rid of ip_id_count ... [ Upstream commit 73f156a6e8 ] Ideally, we would need to generate IP ID using a per destination IP generator. linux kernels used inet_peer cache for this purpose, but this had a huge cost on servers disabling MTU discovery. 1) each inet_peer struct consumes 192 bytes 2) inetpeer cache uses a binary tree of inet_peer structs, with a nominal size of ~66000 elements under load. 3) lookups in this tree are hitting a lot of cache lines, as tree depth is about 20. 4) If server deals with many tcp flows, we have a high probability of not finding the inet_peer, allocating a fresh one, inserting it in the tree with same initial ip_id_count, (cf secure_ip_id()) 5) We garbage collect inet_peer aggressively. IP ID generation do not have to be 'perfect' Goal is trying to avoid duplicates in a short period of time, so that reassembly units have a chance to complete reassembly of fragments belonging to one message before receiving other fragments with a recycled ID. We simply use an array of generators, and a Jenkin hash using the dst IP as a key. ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it belongs (it is only used from this file) secure_ip_id() and secure_ipv6_id() no longer are needed. Rename ip_select_ident_more() to ip_select_ident_segs() to avoid unnecessary decrement/increment of the number of segments. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-08-14 08:42:35 +08:00
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acpi
asm-generic
crypto	crypto: scatterwalk - Use sg_chain_ptr on chain entries	2013-12-11 22:34:12 -08:00
drm	introduce SIZE_MAX	2014-07-31 12:54:53 -07:00
keys
linux	Revert: "net: ip, ipv6: handle gso skbs in forwarding path"	2014-08-07 12:00:11 -07:00
math-emu
media	media: v4l2: added missing mutex.h include to v4l2-ctrls.h	2013-09-26 17:15:49 -07:00
misc
mtd
net	inetpeer: get rid of ip_id_count	2014-08-14 08:42:35 +08:00
pcmcia
rdma
rxrpc
scsi	ore: Fix wrong math in allocation of per device BIO	2014-02-13 11:51:11 -08:00
sound	ALSA: control: Protect user controls against concurrent access	2014-06-26 15:10:29 -04:00
target
trace	tracing: Fix syscall_*regfunc() vs copy_process() race	2014-07-06 18:49:20 -07:00
video
xen	xen-netfront: reduce gso_max_size to account for max TCP header	2014-06-07 16:02:15 -07:00
Kbuild