From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751638AbXAPUv3 (ORCPT ); Tue, 16 Jan 2007 15:51:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751640AbXAPUv3 (ORCPT ); Tue, 16 Jan 2007 15:51:29 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:50120 "EHLO omx2.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751630AbXAPUv2 (ORCPT ); Tue, 16 Jan 2007 15:51:28 -0500 Date: Tue, 16 Jan 2007 12:51:14 -0800 (PST) From: Christoph Lameter To: Paul Menage cc: akpm@osdl.org, linux-kernel@vger.kernel.org, Nick Piggin , linux-mm@kvack.org, Andi Kleen , Paul Jackson , Dave Chinner Subject: Re: [RFC 8/8] Reduce inode memory usage for systems with a high MAX_NUMNODES In-Reply-To: <6599ad830701161206w7dff0fa8y34f1e74f94ab9051@mail.gmail.com> Message-ID: References: <20070116054743.15358.77287.sendpatchset@schroedinger.engr.sgi.com> <20070116054825.15358.65020.sendpatchset@schroedinger.engr.sgi.com> <6599ad830701161152q75ff29cdo7306c9b8df5c351b@mail.gmail.com> <6599ad830701161206w7dff0fa8y34f1e74f94ab9051@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 16 Jan 2007, Paul Menage wrote: > I was thinking runtime, unless MAX_NUMNODES is less than 64 in which > case you can make the decision at compile time. > > > > > If done at compile time then we will end up with a pointer to an unsigned > > long for a system with <= 64 nodes. If we allocate the nodemask via > > kmalloc then we will always end up with a mininum allocation size of 64 > > bytes. > > Can't we get less overhead with a slab cache with appropriate-sized objects? Ok but then we are going to have quite small objects. Plus we will have additional slab overhead per node. From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 16 Jan 2007 12:51:14 -0800 (PST) From: Christoph Lameter Subject: Re: [RFC 8/8] Reduce inode memory usage for systems with a high MAX_NUMNODES In-Reply-To: <6599ad830701161206w7dff0fa8y34f1e74f94ab9051@mail.gmail.com> Message-ID: References: <20070116054743.15358.77287.sendpatchset@schroedinger.engr.sgi.com> <20070116054825.15358.65020.sendpatchset@schroedinger.engr.sgi.com> <6599ad830701161152q75ff29cdo7306c9b8df5c351b@mail.gmail.com> <6599ad830701161206w7dff0fa8y34f1e74f94ab9051@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Menage Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, Nick Piggin , linux-mm@kvack.org, Andi Kleen , Paul Jackson , Dave Chinner List-ID: On Tue, 16 Jan 2007, Paul Menage wrote: > I was thinking runtime, unless MAX_NUMNODES is less than 64 in which > case you can make the decision at compile time. > > > > > If done at compile time then we will end up with a pointer to an unsigned > > long for a system with <= 64 nodes. If we allocate the nodemask via > > kmalloc then we will always end up with a mininum allocation size of 64 > > bytes. > > Can't we get less overhead with a slab cache with appropriate-sized objects? Ok but then we are going to have quite small objects. Plus we will have additional slab overhead per node. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org