From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH net-next 4/4] ipv6: Add support for non-equal-cost multipath Date: Tue, 9 Jan 2018 20:48:37 -0700 Message-ID: <1dedd203-78ad-5290-fe27-9a8d376a991a@gmail.com> References: <20180109144028.30133-1-idosch@mellanox.com> <20180109144028.30133-5-idosch@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com, pch@ordbogen.com, jkbs@redhat.com, yoshfuji@linux-ipv6.org, mlxsw@mellanox.com To: Ido Schimmel , netdev@vger.kernel.org Return-path: Received: from mail-pl0-f65.google.com ([209.85.160.65]:44877 "EHLO mail-pl0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965232AbeAJDsk (ORCPT ); Tue, 9 Jan 2018 22:48:40 -0500 Received: by mail-pl0-f65.google.com with SMTP id n13so6512487plp.11 for ; Tue, 09 Jan 2018 19:48:39 -0800 (PST) In-Reply-To: <20180109144028.30133-5-idosch@mellanox.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 1/9/18 7:40 AM, Ido Schimmel wrote: > The use of hash-threshold instead of modulo-N makes it trivial to add > support for non-equal-cost multipath. > > Instead of dividing the multipath hash function's output space equally > between the nexthops, each nexthop is assigned a region size which is > proportional to its weight. > > Signed-off-by: Ido Schimmel > --- > include/net/ip6_fib.h | 1 + > net/ipv6/route.c | 11 +++++++---- > 2 files changed, 8 insertions(+), 4 deletions(-) > > diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h > index 97cd05d87780..34ec321d6a03 100644 > --- a/include/net/ip6_fib.h > +++ b/include/net/ip6_fib.h > @@ -171,6 +171,7 @@ struct rt6_info { > u32 rt6i_metric; > u32 rt6i_pmtu; > /* more non-fragment space at head required */ > + int rt6i_nh_weight; > unsigned short rt6i_nfheader_len; > u8 rt6i_protocol; > u8 exception_bucket_flushed:1, Since dst is cacheline aligned there is a hole after rt6i_nh_flags. In patch 1 you put rt6i_nh_upper_bound in that hole. Putting the weight there too keeps those variables together as well as using the open space.