netdev - Re: [PATCH v2] ipv4: Early TCP socket demux.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1340227076.4604.1905.camel@edumazet-glaptop>
Date:	Wed, 20 Jun 2012 23:17:56 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Stephen Hemminger <shemminger@...tta.com>
Cc:	David Miller <davem@...emloft.net>, bhutchings@...arflare.com,
	netdev@...r.kernel.org
Subject: Re: [PATCH v2] ipv4: Early TCP socket demux.

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@...emloft.net> wrote:
> 
> > From: Eric Dumazet <eric.dumazet@...il.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.



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html