Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757286AbYFQJfk (ORCPT ); Tue, 17 Jun 2008 05:35:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754127AbYFQJfM (ORCPT ); Tue, 17 Jun 2008 05:35:12 -0400 Received: from sovereign.computergmbh.de ([85.214.69.204]:44236 "EHLO sovereign.computergmbh.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752077AbYFQJfL (ORCPT ); Tue, 17 Jun 2008 05:35:11 -0400 Date: Tue, 17 Jun 2008 11:35:10 +0200 (CEST) From: Jan Engelhardt To: Maxim Shchetynin cc: linux-fsdevel@vger.kernel.org, Matthew Wilcox , linux-kernel@vger.kernel.org Subject: Re: AZFS file system proposal In-Reply-To: <20080617110655.59c915da@mercedes-benz.boeblingen.de.ibm.com> Message-ID: References: <20080609104650.4f220492@mercedes-benz.boeblingen.de.ibm.com> <20080609125530.GF30405@parisc-linux.org> <20080610104919.504b9826@mercedes-benz.boeblingen.de.ibm.com> <20080617110655.59c915da@mercedes-benz.boeblingen.de.ibm.com> User-Agent: Alpine 1.10 (LNX 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1185 Lines: 33 On Tuesday 2008-06-17 11:06, Maxim Shchetynin wrote: > >> (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. So the reason azfs could be useful is...? >> >+ 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. Exactly, that's what I was asking myself. >I would say you can either mmap it or place a file system on it. The help text implies that I *need* azfs to mmap it - and that sounds like a Rube Goldberg machine. -- 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/