Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752432AbWAFHhq (ORCPT ); Fri, 6 Jan 2006 02:37:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750912AbWAFHhq (ORCPT ); Fri, 6 Jan 2006 02:37:46 -0500 Received: from mf00.sitadelle.com ([212.94.174.67]:20569 "EHLO smtp.cegetel.net") by vger.kernel.org with ESMTP id S1752431AbWAFHhp (ORCPT ); Fri, 6 Jan 2006 02:37:45 -0500 Message-ID: <43BE1E46.3060904@cosmosbay.com> Date: Fri, 06 Jan 2006 08:37:42 +0100 From: Eric Dumazet User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 To: David Lang Cc: Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Shrinks sizeof(files_struct) and better layout References: <20051108185349.6e86cec3.akpm@osdl.org> <437226B1.4040901@cosmosbay.com> <20051109220742.067c5f3a.akpm@osdl.org> <4373698F.9010608@cosmosbay.com> <43BB1178.7020409@cosmosbay.com> <43BBADD5.3070706@cosmosbay.com> <43BE0FC3.7030602@cosmosbay.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1117 Lines: 26 David Lang a ?crit : > Ok, so if you have large numbers of CPU's and large page sizes it's not > useful. however, what about a 2-4 cpu machine with 4k page sizes, 8-32G > of ram (a not unreasonable Opteron system config) that will be running > 5,000-20,000 processes/threads? Dont forget 'struct files_struct' are shared between threads of one process. So may benefit from this 'special cache' only if you plan to run 20.000 processes. > > I know people argue that programs that do such things are bad (and I > definantly agree that they aren't optimized), but the reality is that > some workloads are like that. if a machine is being built for such uses > configuring the kernel to better tolorate such use may be useful If 20.000 process runs on a machine, I doubt the main problem of sysadmin is about the 'struct files_struct' placement in memory :) Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/