From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id EEA0F6B004A for ; Wed, 13 Jul 2011 19:11:24 -0400 (EDT) Date: Wed, 13 Jul 2011 16:11:21 -0700 From: Andrew Morton Subject: Re: [PATCH 2/12] mm: let swap use exceptional entries Message-Id: <20110713161121.17fd98a4.akpm@linux-foundation.org> In-Reply-To: References: <20110618145254.1b333344.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org On Tue, 12 Jul 2011 15:08:58 -0700 (PDT) Hugh Dickins wrote: > > All the crap^Wnice changes made to filemap.c really need some comments, > > please. Particularly when they're keyed off the bland-sounding > > "radix_tree_exception()". Apparently they have something to do with > > swap, but how is the poor reader to know this? > > The naming was intentionally bland, because other filesystems might > in future have other uses for such exceptional entries. > > (I think the field size would generally defeat it, but you can, > for example, imagine a small filesystem wanting to save sector number > there when a page is evicted.) > > But let's go bland when it's more familiar, and such uses materialize - > particularly since I only placed those checks in places where they're > needed now for shmem/tmpfs/swap. > > I'll keep the bland naming, if that's okay, but send a patch adding > a line of comment in such places. Mentioning shmem, tmpfs, swap. A better fix would be to create a nicely-documented filemap-specific function with a non-bland name which simply wraps radix_tree_exception(). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org