From owner-svn-src-head@FreeBSD.ORG Tue Mar 3 09:20:13 2015 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id D32A2F1E; Tue, 3 Mar 2015 09:20:13 +0000 (UTC) Received: from vps1.elischer.org (vps1.elischer.org [204.109.63.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "vps1.elischer.org", Issuer "CA Cert Signing Authority" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 9DA03A54; Tue, 3 Mar 2015 09:20:13 +0000 (UTC) Received: from Julian-MBP3.local (50-196-156-133-static.hfc.comcastbusiness.net [50.196.156.133]) (authenticated bits=0) by vps1.elischer.org (8.14.9/8.14.9) with ESMTP id t239KB89010654 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Tue, 3 Mar 2015 01:20:12 -0800 (PST) (envelope-from julian@freebsd.org) Message-ID: <54F57CC6.9050109@freebsd.org> Date: Tue, 03 Mar 2015 01:20:06 -0800 From: Julian Elischer User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Neel Natu , Davide Italiano Subject: Re: svn commit: r279539 - head/sys/sys References: <201503022005.t22K5HTL062907@svn.freebsd.org> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: John-Mark Gurney , "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Mar 2015 09:20:13 -0000 On 3/2/15 4:55 PM, Neel Natu wrote: > Hi Davide, > > On Mon, Mar 2, 2015 at 12:26 PM, Davide Italiano wrote: >> On Mon, Mar 2, 2015 at 12:05 PM, John-Mark Gurney wrote: >>> Author: jmg >>> Date: Mon Mar 2 20:05:16 2015 >>> New Revision: 279539 >>> URL: https://svnweb.freebsd.org/changeset/base/279539 >>> >>> Log: >>> give others fair warning that _SPARE2 isn't just cxgb, but used by large >>> number of other subsystems, so you probably don't want _SPARE2.. >>> >>> ktr needs an overhaul to really only compile in the ones you want, >>> we've long passed the 31 bits it provides.. >>> >> If you really want to do the overhaul (which would be honestly great), >> I might consider revamping my work for per-cpu KTR buffer and include >> that in the change. Originally it was just an exercise, but then it >> evolved and I've been sitting with it in my local tree for a while. I >> never had the chutzpah to upstream it because it involves fundamental >> changes and breaks compatibility with the old ktrdump(1) format. >> A rather outdated (and maybe not completely functional) version of the >> patch can be found here: >> http://people.freebsd.org/~davide/locking/ktr_percpu.4.diff , which >> should give you an high level view of the change. >> I can update it to the last version and bring up for review, if >> somebody think it might be a sane idea avoiding synchronization on a >> single buffer for KTR. I think it would be a problem... one of the truely useful things about ktr is that it does use a single buffer. this means that you get the true interaction between CPUS. Schedgraph relies on this (as one example). > This would be a very welcome improvement. > > best > Neel > >> -- >> Davide >> > >