From: Tom Herbert <therbert@google.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Changli Gao <xiaosuo@gmail.com>,
David Miller <davem@davemloft.net>,
netdev@vger.kernel.org
Subject: Re: [PATCH v5] rfs: Receive Flow Steering
Date: Tue, 20 Apr 2010 08:04:34 -0700 [thread overview]
Message-ID: <t2y65634d661004200804r15427f19k9d58862f05df94aa@mail.gmail.com> (raw)
In-Reply-To: <1271743164.3845.128.camel@edumazet-laptop>
On Mon, Apr 19, 2010 at 10:59 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> Le mardi 20 avril 2010 à 07:38 +0800, Changli Gao a écrit :
>
>> Does this problem has relationship with your patch? No. If the rxhash
>> isn't provided by hardware, we can get more throughput from you patch,
>> and on the other side, we don't lose anything but potential more hash
>> collision.
>>
>
> I am not sure what you call hash collision. There is no hash chain here.
>
> This 32bit hash is a jhash one, and we only need 1 to 12 bits in it, I
> am pretty sure its OK.
>
Maybe for the purposes of RPS, but hash collisions could definitely be
an issue in RFS. If two active connections hit the same rps_flow
entry this may cause thrashing of those connections between CPUs. I
think your patch may increase the probability of this happening.
>
>
>
next prev parent reply other threads:[~2010-04-20 15:04 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
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 ` Tom Herbert [this message]
2010-04-20 15:39 ` [PATCH v5] rfs: Receive Flow Steering 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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