From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757096Ab2AKL0t (ORCPT ); Wed, 11 Jan 2012 06:26:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46894 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756275Ab2AKL0s (ORCPT ); Wed, 11 Jan 2012 06:26:48 -0500 Message-ID: <4F0D71F0.4030203@redhat.com> Date: Wed, 11 Jan 2012 13:26:40 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:9.0) Gecko/20111222 Thunderbird/9.0 MIME-Version: 1.0 To: "Borzenkov, Andrey" CC: Eric Dumazet , "linux-kernel@vger.kernel.org" Subject: Re: Extermeley large PageTables over 500G on kernel 2.6.32.49 (SLES11 SP1) References: <1326278196.2767.7.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/11/2012 12:52 PM, Borzenkov, Andrey wrote: > > If not, its normal to eat so much memory for page tables > > > > grep VmPTE /proc/*/status > > > > > > Forgive my ignorance. I thought that > > 1. PTE is 8 bytes per page, which is 4K which gives 2K per 1M of memory > 2. All processes sharing the same shared memory share the same page table > > So page table for Oracle SGA 500G would be around 1G and shared by all Oracle clients. Is my assumption incorrect? > The second assumption is incorrect. So fully populated the 2000 processes would consume 2T; they just haven't accessed all the SGA yet. -- error compiling committee.c: too many arguments to function