netdev - Re: [RFC patch net-next-2.6] net: allow multiple rx

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: <4E0CD39C.8060209@gmail.com>
Date:	Thu, 30 Jun 2011 21:50:52 +0200
From:	Nicolas de Pesloüan 
	<nicolas.2p.debian@...il.com>
To:	Jiri Pirko <jpirko@...hat.com>
CC:	netdev@...r.kernel.org, davem@...emloft.net,
	shemminger@...ux-foundation.org, kaber@...sh.net, fubar@...ibm.com,
	eric.dumazet@...il.com, andy@...yhouse.net,
	Ben Greear <greearb@...delatech.com>
Subject: Re: [RFC patch net-next-2.6] net: allow multiple rx_handler registration

Le 30/06/2011 17:16, Jiri Pirko a écrit :
> For some net topos it is necessary to have multiple "soft-net-devices"
> hooked on one netdev. For example very common is to have
> eth<->(br+vlan). Vlan is not using rh_handler (yet) but also for example
> macvlan would be useful to have hooked on same netdev as br.
>
> This patch introduces rx_handler list. size struct net_device stays
> intact. Measured performance regression on eth-br topo is ~1% (on received
> pkts generated by pktgen) and on eth-bond topo it is ~0.25%
>
> On br I think that the performance can be brought back maybe by using per-cpu
> variables to store port in rx_path (I must check this)
>
> Please comment.
>
> Signed-off-by: Jiri Pirko<jpirko@...hat.com>

I like the idea of this patch.

I didn't take time for a technical review yet, but I'm not sure ordering should be static, depending 
on the kind of device (bond, br, macvlan). Ordering is currently static, because it is hard coded.

I think rx_handler_prio should be exposed to userspace, to allow user setup to decide the exact 
order. Default order should be safe, but user should be allowed to force a different order for 
special setups.

	Nicolas.
--
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