Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756262AbZCWKtt (ORCPT ); Mon, 23 Mar 2009 06:49:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755014AbZCWKta (ORCPT ); Mon, 23 Mar 2009 06:49:30 -0400 Received: from mx2.redhat.com ([66.187.237.31]:36189 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754585AbZCWKt3 (ORCPT ); Mon, 23 Mar 2009 06:49:29 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20090323001418.GA32758@cmpxchg.org> References: <20090323001418.GA32758@cmpxchg.org> <20090321102044.GA3427@cmpxchg.org> <1237752784-1989-1-git-send-email-hannes@cmpxchg.org> <20090323084423.490C.A69D9226@jp.fujitsu.com> To: Johannes Weiner Cc: dhowells@redhat.com, KOSAKI Motohiro , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Nick Piggin , Rik van Riel , Peter Zijlstra , MinChan Kim , Lee Schermerhorn Subject: Re: [patch 1/3] mm: decouple unevictable lru from mmu Date: Mon, 23 Mar 2009 10:48:25 +0000 Message-ID: <12087.1237805305@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 959 Lines: 23 Johannes Weiner wrote: > David, why do we need two Kconfig symbols for mlock and the mlock page > bit? Don't we always provide mlock on mmu and never on nommu? Because whilst the PG_mlocked doesn't exist if we don't have mlock() because we're in NOMMU mode, that does not imply that it _does_ exist if we _do_ have mlock() as it's also contingent on having the unevictable LRU. Not only that, CONFIG_HAVE_MLOCK used in mm/internal.h to switch some stuff out based on whether we have mlock() available or not - which is not the same as whether we have PG_mlocked or not. Mainly I thought it made the train of logic easier. Note that neither symbol is actually manually adjustable. David -- 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/