From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id 215A28E0001 for ; Fri, 14 Sep 2018 15:03:26 -0400 (EDT) Received: by mail-pf1-f198.google.com with SMTP id p22-v6so5048452pfj.7 for ; Fri, 14 Sep 2018 12:03:26 -0700 (PDT) Received: from mga18.intel.com (mga18.intel.com. [134.134.136.126]) by mx.google.com with ESMTPS id z2-v6si7708396pgn.494.2018.09.14.12.03.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 14 Sep 2018 12:03:24 -0700 (PDT) Subject: Re: [PATCH V2 0/6] VA to numa node information References: <1536783844-4145-1-git-send-email-prakash.sangappa@oracle.com> <20180913084011.GC20287@dhcp22.suse.cz> <375951d0-f103-dec3-34d8-bbeb2f45f666@oracle.com> <20180914055637.GH20287@dhcp22.suse.cz> <91988f05-2723-3120-5607-40fabe4a170d@oracle.com> From: Dave Hansen Message-ID: <9315ac49-e797-567b-3bb1-36831a524eb6@intel.com> Date: Fri, 14 Sep 2018 12:01:10 -0700 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Prakash Sangappa , Steven Sistare , Michal Hocko Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nao.horiguchi@gmail.com, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, khandual@linux.vnet.ibm.com On 09/14/2018 11:04 AM, Prakash Sangappa wrote: > Also, for valid VMAs in 'maps' file, if the VMA is sparsely > populated with physical pages, the page walk can skip over non > existing page table entires (PMDs) and so can be faster. Note that this only works for things that were _never_ populated. They might be sparse after once being populated and then being reclaimed or discarded. Those will still have all the page tables allocated.