From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id F07176B004D for ; Wed, 11 Nov 2009 05:48:11 -0500 (EST) Date: Wed, 11 Nov 2009 10:48:07 +0000 (GMT) From: Hugh Dickins 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: owner-linux-mm@kvack.org 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 List-ID: 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, 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/ . Don't email: email@kvack.org