From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264296AbTKMOUP (ORCPT ); Thu, 13 Nov 2003 09:20:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264298AbTKMOUP (ORCPT ); Thu, 13 Nov 2003 09:20:15 -0500 Received: from e31.co.us.ibm.com ([32.97.110.129]:47049 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id S264296AbTKMOUJ (ORCPT ); Thu, 13 Nov 2003 09:20:09 -0500 Message-ID: <3FB392EF.6000609@watson.ibm.com> Date: Thu, 13 Nov 2003 09:19:27 -0500 From: Hubertus Franke User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5b) Gecko/20030901 Thunderbird/0.2 X-Accept-Language: en-us, en MIME-Version: 1.0 To: davem@redhat.com, frankeh@watson.ibm.com CC: linux-kernel@vger.kernel.org, karim@opersys.com, jmorris@redhat.com, zanussi@us.ibm.com Subject: Re: [PATCH][RFC] relayfs (1/4) (Documentation) References: <200310122323.48885.rasman@uk.ibm.com> <20031013102520.0671a69d.davem@redhat.com> <200310141132.28339.rasman@uk.ibm.com> <20031014094424.6cff5697.davem@redhat.com> In-Reply-To: <20031014094424.6cff5697.davem@redhat.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org David S. Miller wrote: > On Tue, 14 Oct 2003 11:32:28 +0000 > Richard J Moore wrote: > > >>Interesting, that assumes sequential processing, if not semi-synchronous >>processing of events on the receiver side, which is far from guaranteed when >>considering low-level tracing especially for flight-recorder applications. > > > With netlink you may receive the data asynchronously however you > wish after you've requested a dump. > > I would like to ask that you go study how netlink works and is used > by things like routing daemons before we discuss this further as > it looks to me like half the conversation is going to be showing > you how netlink works. And hey there's even an RFC on netlink :) > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > Dave, is there a short write-up (2-3 pages) about netlink. I like to get a quick understanding about it and how it measures up to relayfs or vice versa. From some of the discussions here I get the feeling that they simply might address orthogonal issues. I recently started using relayfs for various projects after hearing about it at OLS'03. I often need to get information out of the kernel (either debugging in interrupt/scheduling context thus preempting use of printk) or other information for data recording (call it trace or whatever). I don't want to use existing "media" (e.g. syslog) as it either clobbers up that media or I have to search for the information I have put in or the format (typically char) is not appropriate for my use. I simply want a dedicated channel to get to the data in the format that I select. I found relayfs extremely easy to use. Channel setup is a breeze. User level consumption is through file operations. IMHO it just simply can not get any simpler that this.... It works in interrupt/scheduling context. Has extremely low overhead and is stable. I really would like to see relayfs be picked up. Its a loadable filesystem that at least to this user has provided some real value, so why would inclusion be so difficult/objectable. You providing a short document might help me get an appreciation for your argument. -- Hubertus