From: jamal <hadi@cyberus.ca>
To: Andi Kleen <andi@halobates.de>
Cc: Tom Herbert <therbert@google.com>,
davem@davemloft.net, netdev@vger.kernel.org,
eric.dumazet@gmail.com
Subject: Re: [PATCH v5] rfs: Receive Flow Steering
Date: Fri, 16 Apr 2010 09:32:06 -0400 [thread overview]
Message-ID: <1271424726.4606.42.camel@bigi> (raw)
In-Reply-To: <87r5mf8va9.fsf@basil.nowhere.org>
On Fri, 2010-04-16 at 13:57 +0200, Andi Kleen wrote:
> One thing I've been wondering while reading if this should be made
> socket or SMT aware.
>
> If you're on a hyperthreaded system and sending a IPI
> to your core sibling, which has a completely shared cache hierarchy,
> might not be the best use of cycles.
>
> The same could potentially true for shared L2 or shared L3 cache
> (e.g. only redirect flows between different sockets)
>
> Have you ever considered that?
>
How are you going to schedule the net softirq on an empty queue if you
do this?
BTW, in my tests sending an IPI to an SMT sibling or to another core
didnt make any difference in terms of latency - still 5 microsecs.
I dont have dual Nehalem where we have to cross QPI - there i suspect
it will be longer than 5 microsecs.
cheers,
jamal
next prev parent reply other threads:[~2010-04-16 13:32 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 ` [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 [this message]
2010-04-16 13:42 ` Andi Kleen
2010-04-16 14:05 ` jamal
2010-04-16 15:28 ` Andi Kleen
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