Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754184AbcJDUXr (ORCPT ); Tue, 4 Oct 2016 16:23:47 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36038 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751554AbcJDUXp (ORCPT ); Tue, 4 Oct 2016 16:23:45 -0400 Date: Tue, 4 Oct 2016 15:23:36 -0500 From: Reza Arbab To: Balbir Singh Cc: Benjamin Herrenschmidt , Michael Ellerman , Paul Mackerras , Rob Herring , Frank Rowand , Jonathan Corbet , Andrew Morton , Bharata B Rao , Nathan Fontenot , Stewart Smith , Alistair Popple , "Aneesh Kumar K.V" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3 4/5] powerpc/mm: restore top-down allocation when using movable_node References: <1474828616-16608-1-git-send-email-arbab@linux.vnet.ibm.com> <1474828616-16608-5-git-send-email-arbab@linux.vnet.ibm.com> <1474924351.2857.255.camel@kernel.crashing.org> <20160927001413.o72fqpfsnsxpu5qq@arbab-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: Organization: IBM Linux Technology Center User-Agent: Mutt/1.6.2-neo (2016-08-21) X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16100420-0056-0000-0000-0000018A108B X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00005852; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000186; SDB=6.00764309; UDB=6.00365009; IPR=6.00540089; BA=6.00004783; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00012872; XFM=3.00000011; UTC=2016-10-04 20:23:43 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16100420-0057-0000-0000-000005BD289C Message-Id: <20161004202336.cp7o3772ygfn4o3k@arbab-laptop.austin.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-10-04_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609300000 definitions=main-1610040348 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1034 Lines: 26 On Tue, Oct 04, 2016 at 11:48:30AM +1100, Balbir Singh wrote: >On 27/09/16 10:14, Reza Arbab wrote: >> Right. To be clear, the background info I put in the commit log >> refers to x86, where the SRAT can describe movable nodes which exist >> at boot. They're trying to avoid allocations from those nodes before >> they've been identified. >> >> On power, movable nodes can only exist via hotplug, so that scenario >> can't happen. We can immediately go back to top-down allocation. That >> is the missing call being added in the patch. > >Can we fix cmdline_parse_movable_node() to do the right thing? I >suspect that code is heavily x86 only in the sense that no other arch >needs it. Good idea. We could change it so things only go bottom-up on x86 in the first place. A nice consequence is that CONFIG_MOVABLE_NODE would then basically be usable on any platform with memory hotplug, not just PPC64 and X86_64. I'll see if I can move the relevant code into an arch_*() call or otherwise factor it out. -- Reza Arbab