From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751823AbbERVEN (ORCPT ); Mon, 18 May 2015 17:04:13 -0400 Received: from www.linutronix.de ([62.245.132.108]:51195 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbbERVEI (ORCPT ); Mon, 18 May 2015 17:04:08 -0400 Date: Mon, 18 May 2015 23:04:18 +0200 (CEST) From: Thomas Gleixner To: Dave Hansen cc: linux-kernel@vger.kernel.org, x86@kernel.org, dave.hansen@linux.intel.com Subject: Re: [PATCH 10/19] x86, mpx: trace ranged MPX operations In-Reply-To: <20150508185952.6913B3F4@viggo.jf.intel.com> Message-ID: References: <20150508185948.4C19F4B0@viggo.jf.intel.com> <20150508185952.6913B3F4@viggo.jf.intel.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 8 May 2015, Dave Hansen wrote: > When MPX can not free an entire bounds table, it will instead > try to zap unused parts of a bounds table to free the backing > memory. This decreases RSS (resident set size) without > decreasing the virtual space allocated for bounds tables. > > trace attempts to find bounds tables: My first reading was: "The trace attempts to find bounds tables" "Trace the attempts to find bounds tables" is what you actually mean. > This event traces any time we go looking to unmap a bounds table You have two events .... > for a given virtual address range. This is useful to ensure > that the kernel actually "tried" to free a bounds table versus > times it succeeded. > > It might try and fail if it realized that a table was shared > with an adjacent VMA which is not being unmapped. So rewording that would probably create a useful changelog. Thanks, tglx