From: Eric Dumazet <edumazet@google.com>
Date: Wed, 13 May 2015 00:24:50 +0000 (-0700)
Subject: netlink: move nl_table in read_mostly section
X-Git-Tag: omap-for-v4.2/wakeirq-drivers-v2^2~2^2~65^2~33
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=91dd93f956b9ea9ecf47fd4b9acd2d2e7f980303;p=pandora-kernel.git

netlink: move nl_table in read_mostly section

netlink sockets creation and deletion heavily modify nl_table_users
and nl_table_lock.

If nl_table is sharing one cache line with one of them, netlink
performance is really bad on SMP.

ffffffff81ff5f00 B nl_table
ffffffff81ff5f0c b nl_table_users

Putting nl_table in read_mostly section increased performance
of my open/delete netlink sockets test by about 80 %

This came up while diagnosing a getaddrinfo() problem.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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