Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757136Ab0BLRtX (ORCPT ); Fri, 12 Feb 2010 12:49:23 -0500 Received: from hera.kernel.org ([140.211.167.34]:49934 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756494Ab0BLRtV (ORCPT ); Fri, 12 Feb 2010 12:49:21 -0500 Message-ID: <4B759635.1080908@kernel.org> Date: Sat, 13 Feb 2010 02:56:05 +0900 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-1.1.1 Thunderbird/3.0 MIME-Version: 1.0 To: Miklos Szeredi CC: mszeredi@suse.cz, linux-kernel@vger.kernel.org, fuse-devel@lists.sourceforge.net, polynomial-c@gentoo.org, akpm@linux-foundation.org Subject: Re: [fuse-devel] [PATCH] FUSE/CUSE: implement direct mmap support References: <4B70FBE4.7050700@kernel.org> <4B7296DF.207@kernel.org> <4B729F07.8020704@kernel.org> <4B72A802.6040009@kernel.org> <4B7344A4.1030607@kernel.org> <4B73EE68.4070004@kernel.org> <4B73FE96.2080707@kernel.org> <4B74065D.2000707@kernel.org> <4B740CFB.7060409@kernel.org> <4B749BDF.8000807@kernel.org> <4B7558C1.2060405@kernel.org> In-Reply-To: X-Enigmail-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Fri, 12 Feb 2010 17:48:34 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1306 Lines: 37 Hello, On 02/12/2010 10:53 PM, Miklos Szeredi wrote: > That dev_offset value is used as an offset into the server side mmap > address space. And yes, vma->vm_pgoff and dev_offset should be SHMLBA > multiples apart. Alright. > But don't call that _adjustment_. That's totally confusing, these are > *two* *different* *offsets*. At this point, we're completely in the realm of the babel tower. Unless we define all the terms explicitly, I don't think using or not using a single word would make much difference. Working with FUSE gets a bit confusing regarding which term means what but with multiple process address spaces and the dmmap address space and all the offsets, it's getting pretty ridiculous. > There's an alignment requirement but that's all. If they are the > same that is pure coincidence. > > And dev_offset (which points into the dmmap address space) is only > required if the filesystem/CUSE driver needs server side mmap. Hmmm... w/o the dev_offset how would the server designate which area to use for the client? Thanks. -- tejun -- 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/