Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757296AbZKKKsJ (ORCPT ); Wed, 11 Nov 2009 05:48:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756374AbZKKKsI (ORCPT ); Wed, 11 Nov 2009 05:48:08 -0500 Received: from mk-filter-4-a-1.mail.uk.tiscali.com ([212.74.100.55]:55414 "EHLO mk-filter-4-a-1.mail.uk.tiscali.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755694AbZKKKsH (ORCPT ); Wed, 11 Nov 2009 05:48:07 -0500 X-Trace: 284228141/mk-filter-4.mail.uk.tiscali.com/B2C/$b2c-THROTTLED-DYNAMIC/b2c-CUSTOMER-DYNAMIC-IP/80.41.12.20/None/hugh.dickins@tiscali.co.uk X-SBRS: None X-RemoteIP: 80.41.12.20 X-IP-MAIL-FROM: hugh.dickins@tiscali.co.uk X-SMTP-AUTH: X-MUA: X-IP-BHB: Once X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AvQAAGol+kpQKQwU/2dsb2JhbAAI3BOEPAQ X-IronPort-AV: E=Sophos;i="4.44,722,1249254000"; d="scan'208";a="284228141" Date: Wed, 11 Nov 2009 10:48:07 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@sister.anvils To: KOSAKI Motohiro cc: Andrew Morton , Izik Eidus , Andrea Arcangeli , Nick Piggin , Rik van Riel , Lee Schermerhorn , Andi Kleen , Wu Fengguang , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 3/6] mm: CONFIG_MMU for PG_mlocked In-Reply-To: <20091111101315.FD33.A69D9226@jp.fujitsu.com> Message-ID: References: <20091111101315.FD33.A69D9226@jp.fujitsu.com> 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: 1376 Lines: 29 On Wed, 11 Nov 2009, KOSAKI Motohiro wrote: > > Remove three degrees of obfuscation, left over from when we had > > CONFIG_UNEVICTABLE_LRU. MLOCK_PAGES is CONFIG_HAVE_MLOCKED_PAGE_BIT > > is CONFIG_HAVE_MLOCK is CONFIG_MMU. rmap.o (and memory-failure.o) > > are only built when CONFIG_MMU, so don't need such conditions at all. > > I don't recall why Lee added this config option. but it seems very > reasonable and I storongly like it. > > At least, vmscan folks never said "please try to disable CONFIG_MLOCK". > It mean this option didn't help our debug. > > Reviewed-by: KOSAKI Motohiro Thanks. CONFIG_HAVE_MLOCKED_PAGE_BIT and CONFIG_HAVE_MLOCK were both just internal, automatically defaulted options which the user never saw (except in .config). I think they were there to sort out the interdependencies between CONFIG_MMU and CONFIG_UNEVICTABLE_LRU, and probably other historical issues while people decided whether or not to go ahead with having a page bit for the thing. So no user should notice their disappearance: removing them just makes the code clearer, that's all. Hugh -- 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/