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>
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 @@
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
