tree 4ea94902a65b0f3ca46ec82652da39b0dea59d55
parent bcefe17cffd06efdda3e7ad679ea743236e6271a
author Eric Dumazet <edumazet@google.com> 1371292210 -0700
committer David S. Miller <davem@davemloft.net> 1371708412 -0700

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>