From: dlg <dlg@openbsd.org>
Date: Thu, 8 Oct 2015 11:39:59 +0000 (+0000)
Subject: if the mbuf has a valid flowid, use it instead of using siphash24
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=6081070972e396d68bcbec5014c0d14e154e43c0;p=openbsd

if the mbuf has a valid flowid, use it instead of using siphash24
and a bunch of header fields we have to parse the mbuf for.

siphash24 is about 20% of the cost of sending a udp packet on a
trunk interface with tcpbench on my box. if there's a flowid set
we get all that back.

ok mpi@ mikeb@ sthen@
---

diff --git a/sys/net/if_trunk.c b/sys/net/if_trunk.c
index 8678fe4f1bb..4285dbe0d12 100644
--- a/sys/net/if_trunk.c
+++ b/sys/net/if_trunk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_trunk.c,v 1.119 2015/10/05 13:00:04 mikeb Exp $	*/
+/*	$OpenBSD: if_trunk.c,v 1.120 2015/10/08 11:39:59 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005, 2006, 2007 Reyk Floeter <reyk@openbsd.org>
@@ -969,6 +969,9 @@ trunk_hashmbuf(struct mbuf *m, SIPHASH_KEY *key)
 #endif
 	SIPHASH_CTX ctx;
 
+	if (m->m_pkthdr.flowid & M_FLOWID_VALID)
+		return (m->m_pkthdr.flowid & M_FLOWID_MASK);
+
 	SipHash24_Init(&ctx, key);
 	off = sizeof(*eh);
 	if (m->m_len < off)