From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993308AbXDTTBq (ORCPT ); Fri, 20 Apr 2007 15:01:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2993318AbXDTTBq (ORCPT ); Fri, 20 Apr 2007 15:01:46 -0400 Received: from smtp1.linux-foundation.org ([65.172.181.25]:56327 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993308AbXDTTBo (ORCPT ); Fri, 20 Apr 2007 15:01:44 -0400 Date: Fri, 20 Apr 2007 12:00:36 -0700 From: Stephen Hemminger To: Matt Mackall Cc: Andrew Morton , Keiichi KII , davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [RFC][PATCH -mm take4 2/6] support multiple logging Message-ID: <20070420120036.2a96cf8d@dxpl.pdx.osdl.net> In-Reply-To: <20070420182109.GR11115@waste.org> References: <462605DC.2080804@bx.jp.nec.com> <462609D1.50300@bx.jp.nec.com> <20070419210813.a599c54f.akpm@linux-foundation.org> <46288D11.4000801@bx.jp.nec.com> <20070420111526.01ad7f4c.akpm@linux-foundation.org> <20070420182109.GR11115@waste.org> Organization: The Linux Foundation X-Mailer: Claws Mail 2.8.1 (GTK+ 2.10.8; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Apr 2007 13:21:10 -0500 Matt Mackall wrote: > On Fri, Apr 20, 2007 at 11:15:26AM -0700, Andrew Morton wrote: > > On Fri, 20 Apr 2007 18:51:13 +0900 > > Keiichi KII wrote: > > > > > > I started to do some cleanups and fixups here, but abandoned it when it was > > > > all getting a bit large. > > > > > > > > Here are some fixes against this patch: > > > > > > I'm going to fix my patches by following your reviews and send new patches > > > on the LKML and the netdev ML in a few days. > > > > > > > Well.. before you can finish this work we need to decide upon what the > > interface to userspace will be. > > > > - The miscdev isn't appropriate > > > > - netlink remains a possibility > > > > - Stephen suggests an ioctl against a socket and davem suggests socket > > options, but it's unclear to me how that socket will get bound to > > netconsole? > > Yeah, that's a bit of a head-scratcher. > > > either way, I agree with the overall thrust of this work: netconsole is > > useful in production environments, can become more useful and will need > > runtime configurability. > > > > > > I wonder if we're approaching this in the right way, however... > > > > At a high level, netconsole is just a flow of UDP packets between two > > machines. The kernel already has rich and well-understood ways of creating > > and configuring such flows. > > > > So... instead of creating a brand new way of configuring such a flow via > > sysfs and ioctl, could we instead create a flow using the existing > > mechanisms (presumably the socket API) and then "transfer" the information > > from that flow over to netconsole by some means?? > > We don't really have anything that corresponds to netpoll's > connections at higher levels. > > I'm tempted to say we should make this work more like the dummy > network device. ie: > > modprobe netconsole -o netcon1 [params] > modprobe netconsole -o netcon2 [params] The configuration of netconsole's looks like the configuration of routes. Granted you probably have more routes than netconsoles, but the interface issues are similar. Netlink with a small application wouldn't be nice. And having /proc/net/netconsole (read-only) would be good for the netlink impaired.