From patchwork Wed May 16 23:06:40 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 159775 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 8D05FB6FBB for ; Thu, 17 May 2012 09:07:24 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760752Ab2EPXHW (ORCPT ); Wed, 16 May 2012 19:07:22 -0400 Received: from mail.us.es ([193.147.175.20]:39156 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760748Ab2EPXHV (ORCPT ); Wed, 16 May 2012 19:07:21 -0400 Received: (qmail 30218 invoked from network); 17 May 2012 01:07:20 +0200 Received: from unknown (HELO us.es) (192.168.2.11) by us.es with SMTP; 17 May 2012 01:07:20 +0200 Received: (qmail 27069 invoked by uid 507); 16 May 2012 23:07:17 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on antivirus1 X-Spam-Level: X-Spam-Status: No, score=-97.0 required=7.5 tests=BAYES_50,KHOP_DYNAMIC, RCVD_IN_BRBL_LASTEXT,RCVD_IN_PBL,RCVD_IN_SORBS_DUL,RDNS_DYNAMIC, USER_IN_WHITELIST autolearn=disabled version=3.3.1 Received: from 127.0.0.1 by antivirus1 (envelope-from , uid 501) with qmail-scanner-2.08 (clamdscan: 0.97.4/14927. Clear:RC:1(127.0.0.1):. Processed in 0.038116 secs); 16 May 2012 23:07:17 -0000 Received: from unknown (HELO antivirus1) (127.0.0.1) by us.es with SMTP; 16 May 2012 23:07:16 -0000 Received: from 192.168.1.13 (192.168.1.13) by antivirus1 (F-Secure/fsigk_smtp/407/antivirus1); Thu, 17 May 2012 01:07:16 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/407/antivirus1) Received: (qmail 6660 invoked from network); 17 May 2012 01:07:39 +0200 Received: from 27.71.221.87.dynamic.jazztel.es (HELO localhost.localdomain) (pneira@us.es@87.221.71.27) by us.es with SMTP; 17 May 2012 01:07:39 +0200 From: pablo@netfilter.org To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 3/7] netfilter: xt_HMARK: modulus is expensive for hash calculation Date: Thu, 17 May 2012 01:06:40 +0200 Message-Id: <1337209604-3412-4-git-send-email-pablo@netfilter.org> X-Mailer: git-send-email 1.7.10 In-Reply-To: <1337209604-3412-1-git-send-email-pablo@netfilter.org> References: <1337209604-3412-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Pablo Neira Ayuso Use: ((u64)(HASH_VAL * HASH_SIZE)) >> 32 as suggested by David S. Miller. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_HMARK.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/xt_HMARK.c b/net/netfilter/xt_HMARK.c index 5817d03..0a96a43 100644 --- a/net/netfilter/xt_HMARK.c +++ b/net/netfilter/xt_HMARK.c @@ -109,7 +109,7 @@ hmark_hash(struct hmark_tuple *t, const struct xt_hmark_info *info) hash = jhash_3words(t->src, t->dst, t->uports.v32, info->hashrnd); hash = hash ^ (t->proto & info->proto_mask); - return (hash % info->hmodulus) + info->hoffset; + return (((u64)hash * info->hmodulus) >> 32) + info->hoffset; } static void