From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anshuman Khandual Subject: Re: [PATCH 2/2] mm: Consolidate page table accounting Date: Thu, 5 Oct 2017 10:38:29 +0530 Message-ID: <3aabab03-7f0a-e82e-a1c2-79120aed5ace@linux.vnet.ibm.com> References: <20171004163648.11234-1-kirill.shutemov@linux.intel.com> <20171004163648.11234-2-kirill.shutemov@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171004163648.11234-2-kirill.shutemov-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Kirill A. Shutemov" , Andrew Morton Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko List-Id: linux-api@vger.kernel.org On 10/04/2017 10:06 PM, Kirill A. Shutemov wrote: > This patch switches page table accounting to single counter from > three -- nr_ptes, nr_pmds and nr_puds. > > mm->pgtables_bytes is now used to account page table levels. We use > bytes, because page table size for different levels of page table tree > may be different. > > The change has user-visible effect: we don't have VmPMD and VmPUD > reported in /proc/[pid]/status. Not sure if anybody uses them. > (As alternative, we can always report 0 kB for them.) > > OOM-killer report is also slightly changed: we now report pgtables_bytes > instead of nr_ptes, nr_pmd, nr_puds. Could you please mention the motivation of doing this ? Why we are consolidating the counters which also changes /proc/ interface as well as OOM report ? What is the benefit ? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id EFF046B0033 for ; Thu, 5 Oct 2017 01:08:42 -0400 (EDT) Received: by mail-wm0-f70.google.com with SMTP id r202so8423994wmd.1 for ; Wed, 04 Oct 2017 22:08:42 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id b12si1026235edm.95.2017.10.04.22.08.40 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 04 Oct 2017 22:08:41 -0700 (PDT) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v9554TIJ070553 for ; Thu, 5 Oct 2017 01:08:39 -0400 Received: from e23smtp03.au.ibm.com (e23smtp03.au.ibm.com [202.81.31.145]) by mx0b-001b2d01.pphosted.com with ESMTP id 2dd94jduyu-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 05 Oct 2017 01:08:39 -0400 Received: from localhost by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 5 Oct 2017 15:08:36 +1000 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v9558XNG30933202 for ; Thu, 5 Oct 2017 16:08:33 +1100 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v9558OJg017820 for ; Thu, 5 Oct 2017 16:08:24 +1100 Subject: Re: [PATCH 2/2] mm: Consolidate page table accounting References: <20171004163648.11234-1-kirill.shutemov@linux.intel.com> <20171004163648.11234-2-kirill.shutemov@linux.intel.com> From: Anshuman Khandual Date: Thu, 5 Oct 2017 10:38:29 +0530 MIME-Version: 1.0 In-Reply-To: <20171004163648.11234-2-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Message-Id: <3aabab03-7f0a-e82e-a1c2-79120aed5ace@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Michal Hocko On 10/04/2017 10:06 PM, Kirill A. Shutemov wrote: > This patch switches page table accounting to single counter from > three -- nr_ptes, nr_pmds and nr_puds. > > mm->pgtables_bytes is now used to account page table levels. We use > bytes, because page table size for different levels of page table tree > may be different. > > The change has user-visible effect: we don't have VmPMD and VmPUD > reported in /proc/[pid]/status. Not sure if anybody uses them. > (As alternative, we can always report 0 kB for them.) > > OOM-killer report is also slightly changed: we now report pgtables_bytes > instead of nr_ptes, nr_pmd, nr_puds. Could you please mention the motivation of doing this ? Why we are consolidating the counters which also changes /proc/ interface as well as OOM report ? What is the benefit ? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751273AbdJEFIn (ORCPT ); Thu, 5 Oct 2017 01:08:43 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57804 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750811AbdJEFIm (ORCPT ); Thu, 5 Oct 2017 01:08:42 -0400 Subject: Re: [PATCH 2/2] mm: Consolidate page table accounting To: "Kirill A. Shutemov" , Andrew Morton References: <20171004163648.11234-1-kirill.shutemov@linux.intel.com> <20171004163648.11234-2-kirill.shutemov@linux.intel.com> Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Michal Hocko From: Anshuman Khandual Date: Thu, 5 Oct 2017 10:38:29 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20171004163648.11234-2-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable x-cbid: 17100505-0012-0000-0000-0000025F50D1 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17100505-0013-0000-0000-0000077E0974 Message-Id: <3aabab03-7f0a-e82e-a1c2-79120aed5ace@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-05_03:,, 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=8.0.1-1707230000 definitions=main-1710050069 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/04/2017 10:06 PM, Kirill A. Shutemov wrote: > This patch switches page table accounting to single counter from > three -- nr_ptes, nr_pmds and nr_puds. > > mm->pgtables_bytes is now used to account page table levels. We use > bytes, because page table size for different levels of page table tree > may be different. > > The change has user-visible effect: we don't have VmPMD and VmPUD > reported in /proc/[pid]/status. Not sure if anybody uses them. > (As alternative, we can always report 0 kB for them.) > > OOM-killer report is also slightly changed: we now report pgtables_bytes > instead of nr_ptes, nr_pmd, nr_puds. Could you please mention the motivation of doing this ? Why we are consolidating the counters which also changes /proc/ interface as well as OOM report ? What is the benefit ?