netdev - Re: [PATCH v3 net-next] net: introduce dev_set

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: <1383573501.4291.115.camel@edumazet-glaptop2.roam.corp.google.com>
Date:	Mon, 04 Nov 2013 05:58:21 -0800
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Herbert Xu <herbert@...dor.apana.org.au>
Cc:	Ben Hutchings <bhutchings@...arflare.com>,
	David Miller <davem@...emloft.net>,
	christoph.paasch@...ouvain.be, netdev@...r.kernel.org,
	hkchu@...gle.com, mwdalton@...gle.com
Subject: Re: [PATCH v3 net-next] net: introduce dev_set_forwarding()

On Mon, 2013-11-04 at 15:21 +0800, Herbert Xu wrote:
> On Sun, Nov 03, 2013 at 11:10:41PM -0800, Eric Dumazet wrote:
> >
> > Using frag_list for skb meant to be delivered to local stack is mostly
> > fine. Its for forwarding that its not a win, since no driver actually
> > supports frag_list and we revert to skb_segment().
> 
> Sigh.
> 
> Most of the gain these days isn't coming from the hardware anymore,
> especially for virtualisation where the network stack is at least
> twice as long.  The gain is in paying the cost of the network once
> instead of n times for an aggregation of n packets.  So with your
> mega-GRO patch, the choice comes down to paying for one trip or
> three trips.  The difference may not be trivial, even for a router.

I do think we are on the same thoughts.

Please take a look at 2613af0ed18a11d5c566a81f9a6510b73180660a
("virtio_net: migrate mergeable rx buffers to page frag allocators")

Notice it also uses frag_list

So if you don't provide a skb_segment() patch, I will.

I had urgent matters last week.


--
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