Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269378AbUIIJTS (ORCPT ); Thu, 9 Sep 2004 05:19:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269379AbUIIJTS (ORCPT ); Thu, 9 Sep 2004 05:19:18 -0400 Received: from [195.23.16.24] ([195.23.16.24]:11460 "EHLO bipbip.comserver-pie.com") by vger.kernel.org with ESMTP id S269378AbUIIJTI (ORCPT ); Thu, 9 Sep 2004 05:19:08 -0400 Message-ID: <4140200B.9060408@grupopie.com> Date: Thu, 09 Sep 2004 10:19:07 +0100 From: Paulo Marques Organization: Grupo PIE User-Agent: Mozilla Thunderbird 0.7.1 (X11/20040626) X-Accept-Language: en-us, en MIME-Version: 1.0 To: colin Cc: linux-kernel@vger.kernel.org Subject: Re: What File System supports Application XIP References: <009901c4964a$be2468e0$8b1a13ac@realtek.com.tw> In-Reply-To: <009901c4964a$be2468e0$8b1a13ac@realtek.com.tw> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-AntiVirus: checked by Vexira MailArmor (version: 2.0.1.16; VAE: 6.27.0.6; VDF: 6.27.0.51; host: bipbip) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1629 Lines: 41 colin wrote: > > Hi there, > We are developing embedded Linux system. Performance is our consideration. > We hope some applications can run as fast as possible, > and are think if they can be put in a filesystem image, which resides in > RAM, and run in XIP (eXecute In Place) manners. > I know that Cramfs has supported Application XIP. Is there any other FS that > also supports it? Ramdisk? Ramfs? Romfs? Obvisously cramfs can not support XIP, because the "in-place" image is compressed (unless you have a processor that can execute compressed code :) AFAIK only tmpfs supports XIP because it works on a higher level without using block devices underneath. Ramdisks are simply RAM block devices that behave like any other block device. You can have a compressed image in flash (for instance), decompress everything into a tmpfs and execute from there. I'm not sure, however, that this will be such a performance gain. If you use cramfs (for instance) then the kernel will uncompress and run only the pages that are needed, and they will be cached in page cache so that they will be available again when needed. This way you only waste the RAM you actually need, and can still drop old pages if the application needs more RAM. Just my two cents, -- Paulo Marques - www.grupopie.com To err is human, but to really foul things up requires a computer. Farmers' Almanac, 1978 - 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/