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From: Franco Fichtner <franco@lastsummer.de>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Changli Gao <xiaosuo@gmail.com>,
	David Miller <davem@davemloft.net>,
	therbert@google.com, netdev@vger.kernel.org
Subject: Re: [PATCH net-next-2.6] rps: consistent rxhash
Date: Tue, 20 Apr 2010 14:48:53 +0200	[thread overview]
Message-ID: <4BCDA2B5.4060609@lastsummer.de> (raw)
In-Reply-To: <1271750198.3845.216.camel@edumazet-laptop>

Eric Dumazet wrote:
> In case we compute a software skb->rxhash, we can generate a consistent
> hash : Its value will be the same in both flow directions.
>
> This helps some workloads, like conntracking, since the same state needs
> to be accessed in both directions.
>
> tbench + RFS + this patch gives better results than tbench with default
> kernel configuration (no RPS, no RFS)
>
> Also fixed some sparse warnings.
>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> ---

I thought about this for some time...

Do we really need the port numbers here at all? A simple
addr1^addr2 can provide a good enough pointer for
distribution amongst CPUs.

The real connection tracking is better done locally at the
corresponding CPU. That way a potential cache miss can be
avoided and the still needed hash calculation for
connection tracking will be offloaded.


Franco


  parent reply	other threads:[~2010-04-20 12:48 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-16  5:47 [PATCH v5] rfs: Receive Flow Steering Tom Herbert
2010-04-16  6:33 ` David Miller
2010-04-16  6:56   ` Eric Dumazet
2010-04-16  7:18     ` Eric Dumazet
2010-04-16  7:26       ` David Miller
2010-04-16  7:48         ` Eric Dumazet
2010-04-17  7:52           ` [PATCH net-next-2.6] rps: rps_sock_flow_table is mostly read Eric Dumazet
2010-04-17  7:57             ` David Miller
2010-04-16 15:35     ` [PATCH v5] rfs: Receive Flow Steering Tom Herbert
2010-04-16 18:15       ` Eric Dumazet
2010-04-16 18:35     ` Tom Herbert
2010-04-16 18:53       ` Eric Dumazet
2010-04-16 20:42         ` Tom Herbert
2010-04-16 21:12           ` Eric Dumazet
2010-04-16 21:25             ` Eric Dumazet
2010-04-17 16:10             ` Eric Dumazet
2010-04-17 17:38               ` Tom Herbert
2010-04-18  0:06                 ` Changli Gao
2010-04-18 11:06                   ` Franco Fichtner
2010-04-19 20:09               ` David Miller
2010-04-19 20:23                 ` David Miller
2010-04-19 20:32                   ` Eric Dumazet
2010-04-19 21:19                     ` David Miller
2010-04-26  8:41                       ` Eric Dumazet
2010-04-27 21:59                         ` David Miller
2010-04-27 22:08                           ` Eric Dumazet
2010-04-27 22:10                             ` David Miller
2010-04-19 23:38                     ` Changli Gao
2010-04-20  5:59                       ` Eric Dumazet
2010-04-20  7:56                         ` [PATCH net-next-2.6] rps: consistent rxhash Eric Dumazet
2010-04-20  8:18                           ` David Miller
2010-04-20 12:48                           ` Franco Fichtner [this message]
2010-04-20 13:16                             ` Eric Dumazet
2010-04-20 14:03                               ` Franco Fichtner
2010-04-20 14:57                                 ` Eric Dumazet
2010-04-20 21:41                                   ` David Miller
2010-04-20 23:35                                     ` Changli Gao
2010-04-20 23:38                                       ` David Miller
2010-04-21 19:12                                     ` Tom Herbert
2010-04-23 20:44                                       ` David Miller
2010-05-06  8:06                                       ` David Miller
2010-05-06 14:45                                         ` Tom Herbert
2010-04-20 15:09                             ` Tom Herbert
2010-04-21  9:29                               ` Franco Fichtner
2010-04-21  9:39                                 ` Eric Dumazet
2010-04-21 11:06                                   ` Franco Fichtner
2010-04-21 11:16                                     ` Eric Dumazet
2010-04-20 15:04                         ` [PATCH v5] rfs: Receive Flow Steering Tom Herbert
2010-04-20 15:39                           ` Eric Dumazet
2010-04-16 19:37   ` Eric Dumazet
2010-04-16 22:49     ` David Miller
2010-04-16 22:53       ` David Miller
2010-04-16 22:57         ` David Miller
2010-04-17  0:22           ` Tom Herbert
2010-04-17  0:58             ` David Miller
2010-04-16 11:57 ` Andi Kleen
2010-04-16 13:32   ` jamal
2010-04-16 13:42     ` Andi Kleen
2010-04-16 14:05       ` jamal
2010-04-16 15:28         ` Andi Kleen

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