From: Eric Dumazet <edumazet@google.com>
Date: Sat, 15 Jun 2013 10:30:10 +0000 (-0700)
Subject: htb: refactor struct htb_sched fields for performance
X-Git-Tag: v3.11-rc1~16^2~33
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c9364636dcb01a6fc37ca2c6a51c5aa0c663013c;p=pandora-kernel.git

htb: refactor struct htb_sched fields for performance

htb_sched structures are big, and source of false sharing on SMP.

Every time a packet is queued or dequeue, many cache lines must be
touched because structures are not lay out properly.

By carefully splitting htb_sched in two parts, and define sub structures
to increase data locality, we can improve performance dramatically on
SMP.

New htb_prio structure can also be used in htb_class to increase data
locality.

I got 26 % performance increase on a 24 threads machine, with 200
concurrent netperf in TCP_RR mode, using a HTB hierarchy of 4 classes.

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

Reading git-diff-tree failed