From mboxrd@z Thu Jan 1 00:00:00 1970 From: "prakash.sangappa" Subject: Re: [RFC PATCH] Add /proc//numa_vamaps for numa node information Date: Thu, 3 May 2018 15:39:49 -0700 Message-ID: References: <1525240686-13335-1-git-send-email-prakash.sangappa@oracle.com> Reply-To: prakash.sangappa@oracle.com Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Christopher Lameter Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, akpm@linux-foundation.org, mhocko@suse.com, kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com, drepper@gmail.com, rientjes@google.com List-Id: linux-api@vger.kernel.org On 05/03/2018 11:03 AM, Christopher Lameter wrote: > On Tue, 1 May 2018, Prakash Sangappa wrote: > >> For analysis purpose it is useful to have numa node information >> corresponding mapped address ranges of the process. Currently >> /proc//numa_maps provides list of numa nodes from where pages are >> allocated per VMA of the process. This is not useful if an user needs to >> determine which numa node the mapped pages are allocated from for a >> particular address range. It would have helped if the numa node information >> presented in /proc//numa_maps was broken down by VA ranges showing the >> exact numa node from where the pages have been allocated. > Cant you write a small script that scans the information in numa_maps and > then displays the total pages per NUMA node and then a list of which > ranges have how many pages on a particular node? Don't think we can determine which numa node a given user process address range has pages from, based on the existing 'numa_maps' file. >> reading this file will not be restricted(i.e requiring CAP_SYS_ADMIN). > So a prime motivator here is security restricted access to numa_maps? No it is the opposite. A regular user should be able to determine numa node information.