From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752209AbbALPmW (ORCPT ); Mon, 12 Jan 2015 10:42:22 -0500 Received: from mout.kundenserver.de ([212.227.17.13]:62566 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751372AbbALPmV (ORCPT ); Mon, 12 Jan 2015 10:42:21 -0500 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Catalin Marinas , "Kirill A. Shutemov" , Mark Langsdorf , Linus Torvalds , Linux Kernel Mailing List Subject: Re: Linux 3.19-rc3 Date: Mon, 12 Jan 2015 16:42:14 +0100 Message-ID: <3791313.iJ2hL8LhRB@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <20150112142332.GC19807@e104818-lin.cambridge.arm.com> References: <23318125.rGnCbWvYBR@wuerfel> <20150112142332.GC19807@e104818-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:JjkA86GgrgWjBDILAwNOxwArKRrRwn8U56O1bzpRKRhCmuZlnrm Kh1a1HZ3y/2aR5tZ70eJfhwfHcB6AUjAZy+IjBAupvakcHCtbZ4FAGT8nntfEBeo/kobQjF Xc4siQlPfE41eGoIU5tZsAepLuITFboVwmYIkEW5AqZ8NGOtGd/5r237FxMj2jk/OL3vOOd sdkhkKaB5AaoqwJml+nwA== X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 12 January 2015 14:23:32 Catalin Marinas wrote: > > So, I guess it's run-time cost of the LRU algorithm, especially under > memory pressure. Harder to benchmark though (we'll see when we get > hardware, though probably not very soon). One thing you could try is to add an access fault handler that gathers statistics about number of calls (you could trivially get this by using gcov) and time spent in the handler for a workload that causes memory pressure. Arnd