From: Eric Dumazet <eric.dumazet@gmail.com>
To: Tom Herbert <therbert@google.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: Re: [PATCH v2] rfs: Receive Flow Steering
Date: Tue, 06 Apr 2010 17:10:52 +0200 [thread overview]
Message-ID: <1270566652.2081.38.camel@edumazet-laptop> (raw)
In-Reply-To: <v2n65634d661004060725paf401b5bg1ee692caef565d33@mail.gmail.com>
Le mardi 06 avril 2010 à 07:25 -0700, Tom Herbert a écrit :
> > 2) inet_rps_save_rxhash(sk, skb->rxhash);
> >
> > It should have a check to make sure some part of the stack doesnt feed
> > many different rxhash for a given socket (Make sure we dont pollute flow
> > table with pseudo random values)
> >
> If packets for a connection are always received on the same device, is
> it reasonable to assume the rxhash is constant for that connection?
>
> I suppose it's possible that packets for a same sockets are being
> constantly received on two different devices that are giving different
> rxhashes. This would already be bad in that OOO is probably happening
> anyway. I don't know if thrashing the sock_flow_table is going to
> aggravate this scenario much.
>
> Are there any other degenerative cases you're worried about?
No, I was only considering this mostly as a debugging aid, before RPS is
stable, because mismatches could be unnoticed and performance not
optimal.
next prev parent reply other threads:[~2010-04-06 15:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-06 5:56 [PATCH v2] rfs: Receive Flow Steering Tom Herbert
2010-04-06 13:04 ` Eric Dumazet
2010-04-06 13:42 ` Changli Gao
2010-04-06 14:25 ` Tom Herbert
2010-04-06 15:10 ` Eric Dumazet [this message]
2010-04-08 4:40 ` David Miller
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