From owner-svn-src-all@FreeBSD.ORG Fri Feb 17 09:40:15 2012 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 187DE1065673; Fri, 17 Feb 2012 09:40:15 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-wi0-f182.google.com (mail-wi0-f182.google.com [209.85.212.182]) by mx1.freebsd.org (Postfix) with ESMTP id 9A7768FC19; Fri, 17 Feb 2012 09:40:13 +0000 (UTC) Received: by wibhn14 with SMTP id hn14so2202162wib.13 for ; Fri, 17 Feb 2012 01:40:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=WOEoGap14tjuvxbS8t6/UPzZmNOdHe7Febyay2Vn3OU=; b=ogt4uCd97hL8TUGlQe9dYI3FrGEsmRIphlcDaiZ/NvtPqwL+rntnK0njT0q70rUpS+ 9O4srL7oUw0vTqWHQAtcu8sV/XX+0h5ppAqhoP2Btd5+RIBvR6URDpzAbR/isTv+IfZb tdDUGVnxKBPOIcCx9MFFZLTq5wJg5Iz4yu0mo= MIME-Version: 1.0 Received: by 10.180.101.165 with SMTP id fh5mr2149723wib.10.1329469747292; Fri, 17 Feb 2012 01:09:07 -0800 (PST) Sender: asmrookie@gmail.com Received: by 10.216.177.73 with HTTP; Fri, 17 Feb 2012 01:09:07 -0800 (PST) In-Reply-To: <9CB7ECE8-FF10-43BE-9EBD-16953BE3B193@xcllnt.net> References: <201202160511.q1G5BZNk099785@svn.freebsd.org> <20120216181210.K1423@besplex.bde.org> <4F3CC40D.4000307@freebsd.org> <4F3CC5C4.7020501@FreeBSD.org> <4F3CC8A5.3030107@FreeBSD.org> <20120216174758.GA64180@nargothrond.kdm.org> <20120217053341.R1256@besplex.bde.org> <20120217000846.GA7641@nargothrond.kdm.org> <4F3D9D03.6020507@FreeBSD.org> <9CB7ECE8-FF10-43BE-9EBD-16953BE3B193@xcllnt.net> Date: Fri, 17 Feb 2012 09:09:07 +0000 X-Google-Sender-Auth: SXq6uizTOat_CDC1S3540308DD0 Message-ID: From: Attilio Rao To: Marcel Moolenaar Content-Type: text/plain; charset=UTF-8 X-Mailman-Approved-At: Fri, 17 Feb 2012 12:24:58 +0000 Cc: marcel@freebsd.org, Eitan Adler , svn-src-all@freebsd.org, "Kenneth D. Merry" , Andriy Gapon , src-committers@freebsd.org, Bruce Evans , svn-src-head@freebsd.org, Julian Elischer Subject: Re: svn commit: r231814 - in head/sys: kern sys X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Feb 2012 09:40:15 -0000 2012/2/17, Marcel Moolenaar : > > On Feb 16, 2012, at 4:19 PM, Andriy Gapon wrote: > >> on 17/02/2012 02:08 Kenneth D. Merry said the following: >> [snip] >>>>> On Thu, Feb 16, 2012 at 11:13:09 +0200, Andriy Gapon wrote: >> [snip] >>>>>> For me personally the immediate benefits in the common situations >>>>>> outweighed the >>>>>> problems in the edge cases, although I still believe that we can get >>>>>> the >>>>>> former >>>>>> without sacrifices in the latter. >> [snip] >>> It sounds fine, but I don't have sufficient time to spend on this right >>> now. So I can either back out the changes I mentioned above (assuming we >>> get agreement from avg), or leave things as is. >> >> I stick to what I wrote above and so chose the status quo. >> The backout would make sense if it is immediately followed by commit of a >> better >> solution. Unfortunately, a lack of time here too. > > I think we should lift above the immediate problem and allow for > single- and multi-line messages that are atomically appended to > the message buffer. Console output and propagation of messages > outside of the kernel should all come out of the message buffer > and preserving the atomicity of the messages. > > The message buffer does not have to be a chunk of memory that > we circularly scribble to. It can be a per-cpu linked list of > messages even. Do you think we could inherit much of the code from KTR subsystem? We could use KTR as a scheleton (and possibly improving it) for making a general circular-buffer and then create a new KPI, thus add implementations for KTR, msgbuf, etc. My 2 cents, Attilio -- Peace can only be achieved by understanding - A. Einstein