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Date: Thu, 3 May 2018 13:03:51 -0500 (CDT)
From: Christopher Lameter <cl@linux.com>
Subject: Re: [RFC PATCH] Add /proc/<pid>/numa_vamaps for numa node
 information
In-Reply-To: <1525240686-13335-1-git-send-email-prakash.sangappa@oracle.com>
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To: Prakash Sangappa <prakash.sangappa@oracle.com>
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

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/<pid>/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/<pid>/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?

> 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?