From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751768Ab1F3U0b (ORCPT ); Thu, 30 Jun 2011 16:26:31 -0400 Received: from oproxy6-pub.bluehost.com ([67.222.54.6]:59142 "HELO oproxy6-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751100Ab1F3U02 convert rfc822-to-8bit (ORCPT ); Thu, 30 Jun 2011 16:26:28 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=virtuousgeek.org; h=Received:Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=T7J5yNmJgqI7JsVrT9WWgrdqqYOXLjDlyGjgIz68ceCNYlQhzQICskIPXxxF9mmJ2sRb5EQTtDc0cpvMeqtBeluWWlSampvPi6GPnaH1FOqiAffSsl+6vbV8W5C1Kz43; Date: Thu, 30 Jun 2011 13:26:16 -0700 From: Jesse Barnes To: Bjorn Helgaas Cc: Ram Pai , Oliver Hartkopp , torvalds@linux-foundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, yinghai@kernel.org Subject: Re: [PATCH] PCI: conditional resource-reallocation through kernel parameter pci=realloc Message-ID: <20110630132616.186f2e3f@jbarnes-desktop> In-Reply-To: References: <1309421379-24995-1-git-send-email-linuxram@us.ibm.com> <4E0CACB7.7040709@hartkopp.net> <20110630100705.2d65656c@jbarnes-desktop> <4E0CAE86.6020901@hartkopp.net> <20110630183816.GA20268@ram-laptop> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.22.0; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-Identified-User: {10642:box514.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 67.161.37.189 authed with jbarnes@virtuousgeek.org} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 30 Jun 2011 14:24:24 -0600 Bjorn Helgaas wrote: > On Thu, Jun 30, 2011 at 12:38 PM, Ram Pai wrote: > > On Thu, Jun 30, 2011 at 07:12:38PM +0200, Oliver Hartkopp wrote: > >> On 30.06.2011 19:07, Jesse Barnes wrote: > >> > On Thu, 30 Jun 2011 19:04:55 +0200 > >> > Oliver Hartkopp wrote: > >> > > >> >> On 30.06.2011 10:09, Ram Pai wrote: > >> >>> Multiple attempts to dynamically reallocate pci resources have unfortunately > >> >>> lead to regressions. Though we continue to fix the regressions and fine tune the > >> >>> dynamic-reallocation behavior, we have not reached a acceptable state yet. > >> >>> > >> >>> This patch provides a interim solution. It disables dynamic-reallocation; by > >> >>> default, with the ability to enable it through pci=realloc kernel command line > >> >>> parameter. > >> >> > >> >> What is the advantage of creating an 'interim' kernel parameter instead of > >> >> reverting the problematic commit and queue up a proper solution for 3.1 ? > >> >> > >> >> A kernel parameter needs to be observed, documented and set appropriately. > >> >> > >> >> I would prefer to have an automatic solution - if not in 3.0 then in 3.1 ... > >> > > >> > Yeah, we all want an automatic solution, but we still haven't been able > >> > to achieve one.  My hope is that a parameter will let us keep the code > >> > upstream for Ram and others to keep fixing, then we can move to using > >> > it by default in some future release.  Keeping the code upstream but > >> > behind a param should make development easier; at least that's the goal. > >> > >> What's wrong with the "[PATCH 0/4 v2] PCI: fix cardbus and sriov regressions"? > >> To me it looked good - or don't you trust that fix right now? > > > > I trust the fix :). > > > > Linus's concern was the wrong alignment, which I have fixed, but yet to resend > > the patchset. Will do today. > > > > However Linus's other concern was "too late for 3.0.0, for such a large patch". > > > > There is the other concern about "should cardbus resources be treated nice-to-have?" > > Somewhere along the way, can we get rid of the awkward "nice-to-have" > language? I think "optional" conveys most of the intended meaning, > perhaps lacking the shade that "we'll allocate them if we can." But > the important part is that they are not *required*, and "optional" is > a nice antonym for "required." I think there's a lot more that could be cleaned up in the re-alloc code; e.g. add_head isn't very descriptive as a way to pass around resources that we're tracking for potential re-allocation. -- Jesse Barnes, Intel Open Source Technology Center