From mboxrd@z Thu Jan 1 00:00:00 1970 From: dsahern@kernel.org Subject: [PATCH RFC net-next 18/18] net/ipv4: Optimization for fib_info lookup Date: Fri, 31 Aug 2018 17:49:53 -0700 Message-ID: <20180901004954.7145-19-dsahern@kernel.org> References: <20180901004954.7145-1-dsahern@kernel.org> Cc: roopa@cumulusnetworks.com, sharpd@cumulusnetworks.com, idosch@mellanox.com, davem@davemloft.net, David Ahern To: netdev@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:36798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727272AbeIAFUT (ORCPT ); Sat, 1 Sep 2018 01:20:19 -0400 In-Reply-To: <20180901004954.7145-1-dsahern@kernel.org> Sender: netdev-owner@vger.kernel.org List-ID: From: David Ahern Be optimistic about re-using a fib_info when nexthop id is given and the route does not use metrics. Avoids a memory allocation which in most cases is expected to be freed anyways. Signed-off-by: David Ahern --- net/ipv4/fib_semantics.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 0ddf14512bb3..e4411cd5514b 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -316,6 +316,19 @@ static inline unsigned int fib_devindex_hashfn(unsigned int val) (val >> (DEVINDEX_HASHBITS * 2))) & mask; } +static inline unsigned int fib_info_hashfn_cfg(const struct fib_config *cfg) +{ + unsigned int mask = (fib_info_hash_size - 1); + unsigned int val = 0; + + val ^= (cfg->fc_protocol << 8) | cfg->fc_scope; + val ^= (__force u32)cfg->fc_prefsrc; + val ^= cfg->fc_priority; + val ^= fib_devindex_hashfn(cfg->fc_nh_id); + + return (val ^ (val >> 7) ^ (val >> 12)) & mask; +} + static inline unsigned int fib_info_hashfn(const struct fib_info *fi) { unsigned int mask = (fib_info_hash_size - 1); @@ -334,6 +347,35 @@ static inline unsigned int fib_info_hashfn(const struct fib_info *fi) return (val ^ (val >> 7) ^ (val >> 12)) & mask; } +/* no metrics, only nexthop id */ +static struct fib_info *fib_find_info_nh(struct net *net, + const struct fib_config *cfg) +{ + struct hlist_head *head; + struct fib_info *fi; + unsigned int hash; + + hash = fib_info_hashfn_cfg(cfg); + head = &fib_info_hash[hash]; + + hlist_for_each_entry(fi, head, fib_hash) { + if (!net_eq(fi->fib_net, net)) + continue; + if (!fi->nh || fi->nh->id != cfg->fc_nh_id) + continue; + if (cfg->fc_protocol == fi->fib_protocol && + cfg->fc_scope == fi->fib_scope && + cfg->fc_prefsrc == fi->fib_prefsrc && + cfg->fc_priority == fi->fib_priority && + cfg->fc_type == fi->fib_type && + cfg->fc_table == fi->fib_tb_id && + !((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK)) + return fi; + } + + return NULL; +} + static struct fib_info *fib_find_info(const struct fib_info *nfi) { struct hlist_head *head; @@ -1154,6 +1196,12 @@ struct fib_info *fib_create_info(struct fib_config *cfg, goto err_inval; } + if (!cfg->fc_mx) { + fi = fib_find_info_nh(net, cfg); + if (fi) + return fi; + } + nh = nexthop_find_by_id(net, cfg->fc_nh_id); if (!nh) { NL_SET_ERR_MSG(extack, -- 2.11.0