Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754451AbZIUXZL (ORCPT ); Mon, 21 Sep 2009 19:25:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754395AbZIUXZF (ORCPT ); Mon, 21 Sep 2009 19:25:05 -0400 Received: from mga03.intel.com ([143.182.124.21]:15709 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754309AbZIUXZE convert rfc822-to-8bit (ORCPT ); Mon, 21 Sep 2009 19:25:04 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.44,427,1249282800"; d="scan'208";a="190094133" From: "Luck, Tony" To: David Rientjes , Hugh Dickins CC: Andrew Morton , "Yu, Fenghua" , "ebmunson@us.ibm.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-man@vger.kernel.org" , "mtk.manpages@gmail.com" , Randy Dunlap , "rth@twiddle.net" , "ink@jurassic.park.msu.ru" , "linux-ia64@vger.kernel.org" , Arnd Bergmann Date: Mon, 21 Sep 2009 16:25:05 -0700 Subject: RE: [PATCH] remove duplicate asm/mman.h files Thread-Topic: [PATCH] remove duplicate asm/mman.h files Thread-Index: Aco7DpSdHaW9EuyXSqqXWDc83BCZwQAApqCg Message-ID: <57C9024A16AD2D4C97DC78E552063EA3E29CC3F1@orsmsx505.amr.corp.intel.com> References: <200909181848.42192.arnd@arndb.de> <200909211031.25369.arnd@arndb.de> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1268 Lines: 29 >> Is it perhaps the case that some UNIX on ia64 does implement MAP_GROWSUP, >> and these numbers in the Linux ia64 mman.h have been chosen to match that >> reference implementation? Tony will know. But I wonder if you'd do >> better at least to leave a MAP_GROWSUP comment on that line, so that >> somebody doesn't go and reuse the empty slot later on. >> > > Reserving the bit from future use by adding a comment may be helpful, but > then let's do it for MAP_GROWSDOWN too. Tony can only speculate because this bit has been in asm/mman.h since before I started working on Linux (it is in the 2.4.0 version ... which is roughly when I started ... and long before I was responsible for it). Perhaps it was assumed that it would be useful? Linux/ia64 does use upwardly growing memory areas (the h/w register stack engine saves "stack" registers to an area that grows upwards). But since we have survived this long without it actually being implemented, it may be true that we don't really need it after all. -Tony -- 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/