From 3b81af711d639cdcf820836bad6b4ac0f5a761fa Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Mon, 14 May 2012 02:01:46 +0200
Subject: [PATCH] netfilter: xt_HMARK: modulus is expensive for hash
calculation
Use:
((u64)(HASH_VAL * HASH_SIZE)) >> 32
as suggested by David S. Miller.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/xt_HMARK.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
@@ -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
--
1.7.10