From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752786AbcAFXzd (ORCPT ); Wed, 6 Jan 2016 18:55:33 -0500 Received: from arcturus.aphlor.org ([188.246.204.175]:35182 "EHLO arcturus.aphlor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752332AbcAFXza (ORCPT ); Wed, 6 Jan 2016 18:55:30 -0500 Date: Wed, 6 Jan 2016 18:55:27 -0500 From: Dave Jones To: Linux Kernel Cc: x86@kernel.org Subject: weird DirectMap2M accounting. Message-ID: <20160106235527.GA14135@codemonkey.org.uk> Mail-Followup-To: Dave Jones , Linux Kernel , x86@kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-Spam-Score: -2.9 (--) X-Spam-Report: Spam detection software, running on the system "arcturus.aphlor.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: I just spotted this in /proc/meminfo on an old Core2 machine with 4G. DirectMap2M: 18446744073709543424 kB Looks like we subtracted 8192 from 0 somewhere. [...] Content analysis details: (-2.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I just spotted this in /proc/meminfo on an old Core2 machine with 4G. DirectMap2M: 18446744073709543424 kB Looks like we subtracted 8192 from 0 somewhere. Should split_page_count() be checking that direct_pages_count > 0 ? Dave