netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Vincent Bernat <vincent@bernat.im>,
	Wensong Zhang <wensong@linux-vs.org>,
	Simon Horman <horms@verge.net.au>, Julian Anastasov <ja@ssi.bg>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, lvs-devel@vger.kernel.org
Subject: Re: [PATCH net-next v1] ipvs: add consistent source hashing scheduling
Date: Mon, 2 Apr 2018 10:33:27 -0700	[thread overview]
Message-ID: <63c63fab-12ed-8b15-e00e-dc54e5c144eb@gmail.com> (raw)
In-Reply-To: <20180402172025.7380-1-vincent@bernat.im>



On 04/02/2018 10:20 AM, Vincent Bernat wrote:

> +static inline u32
> +ip_vs_csh_permutation(struct ip_vs_dest *d, int j)
> +{
> +	u32 offset, skip;
> +	__be32 addr_fold = d->addr.ip;
> +
> +#ifdef CONFIG_IP_VS_IPV6
> +	if (d->af == AF_INET6)
> +		addr_fold = d->addr.ip6[0]^d->addr.ip6[1]^
> +			d->addr.ip6[2]^d->addr.ip6[3];
> +#endif
> +	addr_fold = ntohl(addr_fold) + ntohs(d->port);
> +	offset = hash_32(addr_fold, 32) % IP_VS_CSH_TAB_SIZE;
> +	skip = (hash_32(addr_fold + 1, 32) % (IP_VS_CSH_TAB_SIZE - 1)) + 1;
> +	return (offset + j * skip) % IP_VS_CSH_TAB_SIZE;
> +}
> +

This does not look very strong to me, particularly the IPv6 folding

I would rather use __ipv6_addr_jhash() instead of ipv6_addr_hash(), even if it is hard coded ;)

  reply	other threads:[~2018-04-02 17:33 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-02 17:20 [PATCH net-next v1] ipvs: add consistent source hashing scheduling Vincent Bernat
2018-04-02 17:33 ` Eric Dumazet [this message]
2018-04-02 17:57   ` Vincent Bernat
2018-04-02 19:05 ` Julian Anastasov
2018-04-02 19:12   ` Vincent Bernat

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=63c63fab-12ed-8b15-e00e-dc54e5c144eb@gmail.com \
    --to=eric.dumazet@gmail.com \
    --cc=davem@davemloft.net \
    --cc=horms@verge.net.au \
    --cc=ja@ssi.bg \
    --cc=lvs-devel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=vincent@bernat.im \
    --cc=wensong@linux-vs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).