From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: Re: [RFC Patch 2/3] bridge: make bridge support netpoll Date: Tue, 23 Mar 2010 13:00:59 +0800 Message-ID: <4BA84B0B.3090908@redhat.com> References: <20100322082059.4967.63492.sendpatchset@localhost.localdomain> <20100322082112.4967.5504.sendpatchset@localhost.localdomain> <1269297307.3552.23.camel@calx> <4BA82186.3010204@redhat.com> <1269318470.3552.54.camel@calx> <4BA84607.7030304@redhat.com> <1269319861.3552.87.camel@calx> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bridge@lists.linux-foundation.org, Andy Gospodarek , Neil Horman , Stephen Hemminger , bonding-devel@lists.sourceforge.net, Jay Vosburgh , David Miller To: Matt Mackall Return-path: In-Reply-To: <1269319861.3552.87.camel@calx> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Matt Mackall wrote: > On Tue, 2010-03-23 at 12:39 +0800, Cong Wang wrote: >> Matt Mackall wrote: >>> On Tue, 2010-03-23 at 10:03 +0800, Cong Wang wrote: >>>> Matt Mackall wrote: >>>>> On Mon, 2010-03-22 at 04:17 -0400, Amerigo Wang wrote: >>>>>> Based on the previous patch, make bridge support netpoll by: >>>>>> >>>>>> 1) implement the 4 methods to support netpoll for bridge; >>>>>> >>>>>> 2) modify netpoll during forwarding packets in bridge; >>>>>> >>>>>> 3) disable netpoll support of bridge when a netpoll-unabled device >>>>>> is added to bridge; >>>>> Not sure if this is the right thing to do. Shouldn't we simply enable >>>>> polling on all devices that support it and warn about the others (aka >>>>> best effort)? >>>>> >>>> I don't think it's a good idea, because we check if a device >>>> supports netpoll by checking if it has ndo_poll_controller method. >>> Uh, what? If we have 5 devices on a bridge and 4 support netpoll, then >>> shouldn't we just send netconsole messages to those 4 devices? Isn't >>> this much better than simply refusing to work? >>> >> How could you let the bridge know netpoll is not sent to >> the one that doesn't support netpoll during setup? This will >> be complex, I am afraid. > > I thought I saw a simple loop over bridge devices at poll time in your > patch. So it should be a simple matter of skipping unsupported devices > in that loop. Nope, we need to check if the target address is owned by a device that doesn't support netpoll or not, simple skipping will not work. > > But Dave thinks there a bigger problems here, so I recommend first > figuring out the architecture issues, then we can get back to the policy > issues. > Ok. Thanks!