Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754876AbYFQJHS (ORCPT ); Tue, 17 Jun 2008 05:07:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752423AbYFQJG7 (ORCPT ); Tue, 17 Jun 2008 05:06:59 -0400 Received: from mtagate4.uk.ibm.com ([195.212.29.137]:9658 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752846AbYFQJG6 convert rfc822-to-8bit (ORCPT ); Tue, 17 Jun 2008 05:06:58 -0400 Date: Tue, 17 Jun 2008 11:06:55 +0200 From: Maxim Shchetynin To: linux-fsdevel@vger.kernel.org Cc: Jan Engelhardt , Matthew Wilcox , linux-kernel@vger.kernel.org Subject: Re: AZFS file system proposal Message-ID: <20080617110655.59c915da@mercedes-benz.boeblingen.de.ibm.com> In-Reply-To: References: <20080609104650.4f220492@mercedes-benz.boeblingen.de.ibm.com> <20080609125530.GF30405@parisc-linux.org> <20080610104919.504b9826@mercedes-benz.boeblingen.de.ibm.com> Organization: IBM Deutschland Entwicklung GmbH X-Mailer: Claws Mail 2.10.0 (GTK+ 2.12.0; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1893 Lines: 48 > >+config AZ_FS > >+ tristate "AZFS filesystem support" > > This is slightly redundant, it should probably be > tristate "AZ filesystem support" I have called it the same way as other file systems (in Kconfig they say "JFS filesystem support", "XFS filesystem support", "NTFS file system support", ...) > >+ help > >+ azfs is a file system for I/O attached memory backing. It requires > >+ a block device with direct_access capability, e.g. axonram. > > (a) What is axonram? > (b) why is axonram direct_access, and my other devices (including > standard PC RAM) not? Axonram is a module specific for IBM CellBlade and allows access to a DDR2 memory attached onto Axon controller. You don't need direct_access and not azfs for main memory because there is already a pretty nice tmpfs for it. > >+ Mounting such device with azfs gives memory mapped access to the > >+ underlying memory to user space. > > Can't I just mmap(/dev/theblockdevice), why would I need to go through > azfs? Yes, you can mmap it. But what does it have to do with a file system. I would say you can either mmap it or place a file system on it. -- Mit freundlichen Grüßen / met vriendelijke groeten / avec regards Maxim V. Shchetynin Linux Kernel Entwicklung IBM Deutschland Entwicklung GmbH Linux für Cell, Abteilung 3250 Schönaicher Straße 220 71032 Böblingen Vorsitzender des Aufsichtsrats: Johann Weihen Geschäftsführung: Herbert Kircher Sitz der Gesellschaft: Böblingen Registriergericht: Amtsgericht Stuttgart, HRB 243294 Fahr nur so schnell wie dein Schutzengel fliegen kann! -- 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/