public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Jiri Pirko <jpirko@redhat•com>
To: Ben Greear <greearb@candelatech•com>
Cc: Stephen Hemminger <shemminger@vyatta•com>,
	netdev@vger•kernel.org, davem@davemloft•net, kaber@trash•net,
	fubar@us•ibm.com, eric.dumazet@gmail•com,
	nicolas.2p.debian@gmail•com, andy@greyhouse•net
Subject: Re: [RFC patch net-next-2.6] net: allow multiple rx_handler registration
Date: Thu, 30 Jun 2011 19:32:58 +0200	[thread overview]
Message-ID: <20110630173258.GC2056@minipsycho> (raw)
In-Reply-To: <4E0CB26C.9070305@candelatech.com>

Thu, Jun 30, 2011 at 07:29:16PM CEST, greearb@candelatech•com wrote:
>On 06/30/2011 10:22 AM, Jiri Pirko wrote:
>>Thu, Jun 30, 2011 at 06:27:12PM CEST, shemminger@vyatta•com wrote:
>>>On Thu, 30 Jun 2011 17:16:49 +0200
>>>Jiri Pirko<jpirko@redhat•com>  wrote:
>>>
>>>>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@redhat•com>
>>>
>>>I am ok with the infrastructure, but why should Vlan use rh_handle.
>>
>>Well why it shoudln't. It would fit into what rx_handler is here for - the
>>code would be more unified. Also net_device struct would lose struct
>>vlan_group __rcu *vlgrp pointer (and reducing net_device size is always
>>good thing).
>>
>>>It is wrong to allow macvlan and bridge to share same device.
>>>Right now the code blocks users from doing lots of stupid things.
>>
>>Right, this is since rx_handler was introduced. Before that all these
>>stupid configs were allowed. It's possible easily to forbid unwanted
>>configs by checking priv flags.
>
>What sorts of stupid things?  I didn't look at your patch, but does it handle
>ordering?  In other words, is a bridge logic always handled before VLAN logic?
>
>The old hard-coded stuff in dev.c inherently determined ordering.  For dynamic
>handlers, we may need to enforce ordering to give the user any chance of doing
>things right (it would be very confusing to have the behaviour change completely
>if you added bridge module before vlan module v/s vlan before bridge).

You should read the patch first :) Ordering is handled there.

>
>Thanks,
>Ben
>>
>>>
>>--
>>To unsubscribe from this list: send the line "unsubscribe netdev" in
>>the body of a message to majordomo@vger•kernel.org
>>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>-- 
>Ben Greear <greearb@candelatech•com>
>Candela Technologies Inc  http://www.candelatech.com
>

  reply	other threads:[~2011-06-30 17:33 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-30 15:16 [RFC patch net-next-2.6] net: allow multiple rx_handler registration Jiri Pirko
2011-06-30 16:27 ` Stephen Hemminger
2011-06-30 17:22   ` Jiri Pirko
2011-06-30 17:29     ` Ben Greear
2011-06-30 17:32       ` Jiri Pirko [this message]
2011-07-01  6:36     ` Michał Mirosław
2011-07-01 14:57       ` Nicolas de Pesloüan
2011-07-01 15:00         ` Jiri Pirko
2011-07-01 15:01         ` Michał Mirosław
2011-07-01 16:45           ` Nicolas de Pesloüan
2011-07-01 16:49             ` Ben Greear
2011-07-01 16:58               ` Nicolas de Pesloüan
2011-07-01 17:08                 ` David Lamparter
2011-07-01 17:50             ` Michał Mirosław
2011-06-30 18:13 ` Ben Greear
2011-06-30 18:28   ` Jiri Pirko
2011-06-30 18:53     ` Ben Greear
2011-06-30 19:50 ` Nicolas de Pesloüan
2011-07-01  5:45   ` Jiri Pirko
2011-07-01 16:55     ` David Lamparter
2011-07-01 12:48 ` Jiri Pirko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110630173258.GC2056@minipsycho \
    --to=jpirko@redhat$(echo .)com \
    --cc=andy@greyhouse$(echo .)net \
    --cc=davem@davemloft$(echo .)net \
    --cc=eric.dumazet@gmail$(echo .)com \
    --cc=fubar@us$(echo .)ibm.com \
    --cc=greearb@candelatech$(echo .)com \
    --cc=kaber@trash$(echo .)net \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=nicolas.2p.debian@gmail$(echo .)com \
    --cc=shemminger@vyatta$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox