From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752368AbbBYGg3 (ORCPT ); Wed, 25 Feb 2015 01:36:29 -0500 Received: from li166-99.members.linode.com ([173.230.156.99]:49828 "EHLO mail.cooper.stevenson.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750764AbbBYGg2 (ORCPT ); Wed, 25 Feb 2015 01:36:28 -0500 Message-ID: <54ECFCE9.9030407@cooper.stevenson.name> Date: Tue, 24 Feb 2015 14:36:25 -0800 From: "D. Cooper Stevenson" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Non-linear Remap Vs. VM Cleanup: Performance Hit Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello All, I read the Linus's release for RC1. One of his favorite features in the release are, "actually some vm cleanups, where this release is getting rid of the largely unused non-linear remapping code (replaced with just emulating it with lots of smaller mappings) and unifies the NUMA and PROTNONE handling for page tables." I understand that non-linear page remapping is unused (and, presumably, reduces the code base size) but according to the remap_file_pages man page (http://man7.org/linux/man-pages/man2/remap_file_pages.2.html) non-linear system will be, "eventually be replaced by a slower in-kernel emulation." Was this a change of necessity? What gives? Also, would you please Cc: me on your replies as I am not a member of the mailing list? Best Regards, -Cooper