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Message-ID: <CA+mtBx-kRmU+xOmaeD3ASaSU5ps5gqV6WRtccdWNtDBXFueHAg@mail.gmail.com>
Date: Mon, 23 Sep 2013 15:45:18 -0700
From: Tom Herbert <therbert@...gle.com>
To: David Miller <davem@...emloft.net>
Cc: Linux Netdev List <netdev@...r.kernel.org>,
"Brandeburg, Jesse" <jesse.brandeburg@...el.com>
Subject: Re:
Disregard...
On Mon, Sep 23, 2013 at 3:41 PM, Tom Herbert <therbert@...gle.com> wrote:
> From cf54b0651b7ea35fab4c398f1732e800550732ef Mon Sep 17 00:00:00 2001
> From: Tom Herbert <therbert@...gle.com>
> Date: Mon, 23 Sep 2013 12:27:17 -0700
> Subject: [PATCH 2/2] net: Use Toeplitz for IPv4 and IPv6 connection hashing
>
> Add a config option to specify which hash to use for IPv4 and IPv6
> established connection hashing. The alternative option is original
> jhash method (this patch sets Toeplitz to default).
>
> Toeplitz is a little more heavy weight than jhash method. For IPv4
> the difference seems to be negligible, for IPv6 there is some
> performance regression due mostly to the fact that Toeplitz hashes
> over all the bits in the IPv6 address whereas Jhash doesn't (this
> implies that Toeplitz might be more secure).
>
> Some performance numbers using 200 netperf TCP_RR clients:
>
> Toeplitz
> IPv4
> 58.72% CPU utilization
> 110/146/198 90/95/99% latencies
> 1.72549e+06 tps
> IPv6
> 72.38% CPU utilization
> 117/168/255 90/95/99% latencies
> 1.58545e+06 tps
>
> Jhash
> IPv4
> 57.67% CPU utilization
> 111/146/196 90/95/99% latencies
> 1.71574e+06 tps
> IPv6
> 71.84% CPU utilization
> 117/166/248 90/95/99% latencies
> 1.59359e+06 tps
>
> Standalone performance measurement:
>
> Toeplitz
> IPv4
> 40 nsecs/hash
> IPv6
> 105 nsecs/hash
> Jhash
> IPv4
> 39 nsecs/hash
> IPv6
> 77 nsecs/hash
>
> Signed-off-by: Tom Herbert <therbert@...gle.com>
> ---
> include/net/inet6_hashtables.h | 16 ++++++++++++++++
> include/net/inet_sock.h | 16 ++++++++++++++++
> net/ipv4/Kconfig | 14 ++++++++++++++
> 3 files changed, 46 insertions(+)
>
> diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
> index f52fa88..492a45b 100644
> --- a/include/net/inet6_hashtables.h
> +++ b/include/net/inet6_hashtables.h
> @@ -32,12 +32,28 @@ static inline unsigned int inet6_ehashfn(struct net *net,
> const struct in6_addr *laddr, const u16 lport,
> const struct in6_addr *faddr, const __be16 fport)
> {
> +#if IS_ENABLED(CONFIG_IP_HASH_TOEPLITZ)
> + struct {
> + struct in6_addr saddr;
> + struct in6_addr daddr;
> + u16 sport;
> + u16 dport;
> + } input;
> +
> + input.daddr = *laddr;
> + input.saddr = *faddr;
> + input.sport = htons(lport);
> + input.dport = fport;
> +
> + return toeplitz_hash((u8 *)&input, toeplitz_net, sizeof(input));
> +#else
> u32 ports = (((u32)lport) << 16) | (__force u32)fport;
>
> return jhash_3words((__force u32)laddr->s6_addr32[3],
> ipv6_addr_jhash(faddr),
> ports,
> inet_ehash_secret + net_hash_mix(net));
> +#endif
> }
>
> static inline int inet6_sk_ehashfn(const struct sock *sk)
> diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
> index 636d203..02e2ee2 100644
> --- a/include/net/inet_sock.h
> +++ b/include/net/inet_sock.h
> @@ -209,10 +209,26 @@ static inline unsigned int inet_ehashfn(struct net *net,
> const __be32 laddr, const __u16 lport,
> const __be32 faddr, const __be16 fport)
> {
> +#if IS_ENABLED(CONFIG_IP_HASH_TOEPLITZ)
> + struct {
> + u32 saddr;
> + u32 daddr;
> + u16 sport;
> + u16 dport;
> + } input;
> +
> + input.saddr = faddr;
> + input.daddr = laddr;
> + input.sport = fport;
> + input.dport = htons(lport);
> +
> + return toeplitz_hash((u8 *)&input, toeplitz_net, sizeof(input));
> +#else
> return jhash_3words((__force __u32) laddr,
> (__force __u32) faddr,
> ((__u32) lport) << 16 | (__force __u32)fport,
> inet_ehash_secret + net_hash_mix(net));
> +#endif
> }
>
> static inline int inet_sk_ehashfn(const struct sock *sk)
> diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
> index 05c57f0..c9a533f 100644
> --- a/net/ipv4/Kconfig
> +++ b/net/ipv4/Kconfig
> @@ -104,6 +104,20 @@ config IP_ROUTE_VERBOSE
> config IP_ROUTE_CLASSID
> bool
>
> +choice
> + prompt "IP: connection hashing algorithm"
> + default IP_HASH_TOEPLITZ
> + help
> + Select the default hashing algortihm for IP connections
> +
> + config IP_HASH_JHASH
> + bool "Jhash"
> +
> + config IP_HASH_TOEPLITZ
> + bool "Toeplitz"
> + select NET_TOEPLITZ
> +endchoice
> +
> config IP_PNP
> bool "IP: kernel level autoconfiguration"
> help
> --
> 1.8.4
>
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