From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752987AbcJMUKP (ORCPT ); Thu, 13 Oct 2016 16:10:15 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43543 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751765AbcJMUJ7 (ORCPT ); Thu, 13 Oct 2016 16:09:59 -0400 Date: Thu, 13 Oct 2016 20:08:03 +0530 From: Anshuman Khandual User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: David Rientjes , Anshuman Khandual CC: Dave Hansen , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [PATCH V4] mm: Add sysfs interface to dump each node's zonelist information References: <1473150666-3875-1-git-send-email-khandual@linux.vnet.ibm.com> <1473302818-23974-1-git-send-email-khandual@linux.vnet.ibm.com> <57D1C914.9090403@intel.com> <57D63CB2.8070003@linux.vnet.ibm.com> <57DCC605.10305@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16101314-0040-0000-0000-000001EC8002 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16101314-0041-0000-0000-00000AADCE4E Message-Id: <57FF9C4B.5040004@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-10-13_08:,, 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-1610130251 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/20/2016 06:24 AM, David Rientjes wrote: > On Sat, 17 Sep 2016, Anshuman Khandual wrote: > >>> > > I'm questioning if this information can be inferred from information >>> > > already in /proc/zoneinfo and sysfs. We know the no-fallback zonelist is >>> > > going to include the local node, and we know the other zonelists are >>> > > either node ordered or zone ordered (or do we need to extend >>> > > vm.numa_zonelist_order for default?). I may have missed what new >>> > > knowledge this interface is imparting on us. >> > >> > IIUC /proc/zoneinfo lists down zone internal state and statistics for >> > all zones on the system at any given point of time. The no-fallback >> > list contains the zones from the local node and fallback (which gets >> > used more often than the no-fallback) list contains all zones either >> > in node-ordered or zone-ordered manner. In most of the platforms the >> > default being the node order but the sequence of present nodes in >> > that order is determined by various factors like NUMA distance, load, >> > presence of CPUs on the node etc. This order of nodes in the fallback >> > list is the most important information derived out of this interface. >> > > The point is that all of this can be inferred with information already > provided, so the additional interface seems unnecessary. The only > extension I think that is needed is to determine if the order is node or > zone when vm.numa_zonelist_order == default and we shouldn't parse this > from dmesg. Okay. Seems like the general view is that this interface is not necessary. Hence wont be posting the debugfs version for now.