From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin LaHaise Subject: [PATCH] fib_semantics: prevent long hash chains in access server config Date: Sat, 12 Jan 2008 13:58:19 -0500 Message-ID: <20080112185819.GA12775@kvack.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from kanga.kvack.org ([66.96.29.28]:44415 "EHLO kanga.kvack.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756740AbYALS6n (ORCPT ); Sat, 12 Jan 2008 13:58:43 -0500 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: This is a patch from a while ago that I'm resending. Basically, in access server configurations, a lot of routes have the same local ip address but on different devices. This fixes the long chains that result from not including the device index in the hash. -ben diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 1351a26..5375824 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -196,11 +196,21 @@ static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info * return 0; } +static inline unsigned int fib_devindex_hashfn(unsigned int val) +{ + unsigned int mask = DEVINDEX_HASHSIZE - 1; + + return (val ^ + (val >> DEVINDEX_HASHBITS) ^ + (val >> (DEVINDEX_HASHBITS * 2))) & mask; +} + static inline unsigned int fib_info_hashfn(const struct fib_info *fi) { unsigned int mask = (fib_hash_size - 1); unsigned int val = fi->fib_nhs; + val ^= fib_devindex_hashfn(fi->fib_dev->ifindex); val ^= fi->fib_protocol; val ^= (__force u32)fi->fib_prefsrc; val ^= fi->fib_priority; @@ -234,15 +244,6 @@ static struct fib_info *fib_find_info(const struct fib_info *nfi) return NULL; } -static inline unsigned int fib_devindex_hashfn(unsigned int val) -{ - unsigned int mask = DEVINDEX_HASHSIZE - 1; - - return (val ^ - (val >> DEVINDEX_HASHBITS) ^ - (val >> (DEVINDEX_HASHBITS * 2))) & mask; -} - /* Check, that the gateway is already configured. Used only by redirect accept routine. */