Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757132AbXK0Fxd (ORCPT ); Tue, 27 Nov 2007 00:53:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751308AbXK0FxY (ORCPT ); Tue, 27 Nov 2007 00:53:24 -0500 Received: from smtp2.linux-foundation.org ([207.189.120.14]:35511 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750799AbXK0FxX (ORCPT ); Tue, 27 Nov 2007 00:53:23 -0500 Date: Mon, 26 Nov 2007 21:53:15 -0800 From: Andrew Morton To: "Bron Gondwana" Cc: "Linus Torvalds" , "Peter Zijlstra" , "Christian Kujau" , "Linux Kernel Mailing List" , "Rob Mueller" Subject: Re: [PATCH 1/1] mm: add dirty_highmem option Message-Id: <20071126215315.3422eaa2.akpm@linux-foundation.org> In-Reply-To: <1196141064.31920.1223402735@webmail.messagingengine.com> References: <20071115052538.GA21522@brong.net> <20071115115049.GA8297@brong.net> <1195155601.22457.25.camel@lappy> <1195159457.22457.35.camel@lappy> <20071122034204.GA14079@brong.net> <20071126205428.c264ccff.akpm@linux-foundation.org> <1196141064.31920.1223402735@webmail.messagingengine.com> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1853 Lines: 53 On Tue, 27 Nov 2007 16:24:24 +1100 "Bron Gondwana" wrote: > On Mon, 26 Nov 2007 20:54:28 -0800, "Andrew Morton" said: > > On Thu, 22 Nov 2007 14:42:04 +1100 Bron Gondwana > > wrote: > > > > > /* > > > + * free highmem will not be subtracted from the total free memory > > > + * for calculating free ratios if vm_dirty_highmem is true > > > + */ > > > +int vm_dirty_highmem; > > > > One would expect that setting dirty_highmem to true would cause highmem > > to > > be accounted in dirty-memory calculations. However with this change > > reality is in fact the inverse of that. > > > > So how about this? > > Actually, I'm confused now. Maybe I chose a bad name to begin with. > Does it mean "I am allowed to dirty high memory" or "my high memory > will be dirty if this is on"? But we're always allowed to dirty highmem - there'd be no point in having it otherwise. Hence the term dirty_highmem is confusing. umm, really you want /proc/sys/vm/dont-account-highmem-in-dirty-memory-calculations, only shorter. Do you agree? If so, then it's still not a very pleasing interface - setting something to "true" to disable a particular piece of kernel behaviour implies a single negation which we don't really need. It would be simpler to have /proc/sys/vm/do-account-highmem-in-dirty-memory-calculations, defaulting to "true" - this has no negations. So... how about /proc/sys/vm/, umm. OK, I give up. Please see if you can think of something less confusing which involves no negations? Thanks. - 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/