Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751602Ab1F3UYs (ORCPT ); Thu, 30 Jun 2011 16:24:48 -0400 Received: from smtp-out.google.com ([216.239.44.51]:48606 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751100Ab1F3UYr convert rfc822-to-8bit (ORCPT ); Thu, 30 Jun 2011 16:24:47 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=dkim-signature:mime-version:in-reply-to:references:from:date: message-id:subject:to:cc:content-type: content-transfer-encoding:x-system-of-record; b=OQsFKzNmFbX1CK1YRRse5mJUbO892jb8/YfS6YH51jZ9jxG1cnWepJCoyFZd8/Jos AmyPME/4t/u8eaatrIRhw== MIME-Version: 1.0 In-Reply-To: <20110630183816.GA20268@ram-laptop> 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> From: Bjorn Helgaas Date: Thu, 30 Jun 2011 14:24:24 -0600 Message-ID: Subject: Re: [PATCH] PCI: conditional resource-reallocation through kernel parameter pci=realloc To: Ram Pai Cc: Oliver Hartkopp , Jesse Barnes , torvalds@linux-foundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, yinghai@kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2521 Lines: 52 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." Bjorn -- 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/