From: Eric Dumazet <eric.dumazet@gmail.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: David Miller <davem@davemloft.net>,
bhutchings@solarflare.com, netdev@vger.kernel.org
Subject: Re: [PATCH v2] ipv4: Early TCP socket demux.
Date: Wed, 20 Jun 2012 23:17:56 +0200 [thread overview]
Message-ID: <1340227076.4604.1905.camel@edumazet-glaptop> (raw)
In-Reply-To: <20120620140454.36847c65@s6510.linuxnetplumber.net>
On Wed, 2012-06-20 at 14:04 -0700, Stephen Hemminger wrote:
> On Wed, 20 Jun 2012 14:01:21 -0700 (PDT)
> David Miller <davem@davemloft.net> wrote:
>
> > From: Eric Dumazet <eric.dumazet@gmail.com>
> > Date: Wed, 20 Jun 2012 20:40:04 +0200
> >
> > > If someone wants to tune its linux router, he probably already disables
> > > GRO because of various issues with too big packets.
> > >
> > > GRO adds a significant cost to forwarding path.
> >
> > No, Ben is right Eric. GRO decreases the costs, because it means we
> > only need to make one forwarding/netfilter/classification decision for
> > N packets instead of 1.
>
> GRO is also important for routers that interact with VM's.
> It helps reduce the per-packet wakeup of the guest VM's.
I spoke of mere routers, I was _not_ saying GRO is useless.
In most routers setups I used, I had to disable GRO, because 64Kbytes
packets on output path broke the tc setups (SFQ)
netfilter cost was hardly a problem, once correctly done.
next prev parent reply other threads:[~2012-06-20 21:18 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 23:39 [PATCH v2] ipv4: Early TCP socket demux David Miller
2012-06-20 0:21 ` Ben Hutchings
2012-06-20 0:54 ` David Miller
2012-06-20 1:03 ` Ben Hutchings
2012-06-20 1:05 ` David Miller
2012-06-20 2:02 ` David Miller
2012-06-20 18:16 ` Ben Hutchings
2012-06-20 2:35 ` Stephen Hemminger
2012-06-20 4:46 ` David Miller
2012-06-20 5:49 ` Eric Dumazet
2012-06-20 5:51 ` Eric Dumazet
2012-06-20 6:14 ` David Miller
2012-06-20 16:21 ` Rick Jones
2012-06-20 5:59 ` Eric Dumazet
2012-06-20 6:14 ` David Miller
2012-06-20 10:15 ` David Miller
2012-06-20 11:03 ` Eric Dumazet
2012-06-20 11:09 ` David Miller
2012-06-20 12:38 ` Eric Dumazet
2012-06-20 22:29 ` David Miller
2012-06-20 18:07 ` Ben Hutchings
2012-06-20 18:40 ` Eric Dumazet
2012-06-20 21:01 ` David Miller
2012-06-20 21:04 ` Stephen Hemminger
2012-06-20 21:17 ` Eric Dumazet [this message]
2012-06-20 21:26 ` David Miller
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