From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 2/3] Add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions Date: Wed, 2 Sep 2009 10:34:40 +0200 Message-ID: <200909021034.40827.arnd@arndb.de> References: <20090901130801.GB7995@us.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Hugh Dickins Cc: Eric B Munson , Mel Gorman , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michael Kerrisk , randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org List-Id: linux-man@vger.kernel.org On Tuesday 01 September 2009, Hugh Dickins wrote: > On Tue, 1 Sep 2009, Eric B Munson wrote: > > On Tue, 01 Sep 2009, Hugh Dickins wrote: > > > > > > That is explained by you #defining MAP_HUGETLB in include/asm-generic/ > > > mman-common.h to a number which is already being used for other MAP_s > > > on some architectures. That's a separate bug which needs to be fixed > > > by distributing the MAP_HUGETLB definition across various asm*/mman.h. > > > > Would it be okay to keep the define in include/asm-generic/mman.h > > if a value that is known free across all architectures is used? > > 0x080000 is not used by any arch and, AFAICT would work just as well. > > That's a very sensible suggestion, but departs from how we have > assigned new numbers up until now: so include/asm-generic/mman-common.h > isn't actually where we'd expect to find a Linux-specific MAP_ define. > > I'd say, yes, do that for now, so as not to hit this conflict while > testing in mmotm. But whether it should stay that way, or later the > arch/*/include/asm/mman.h's be updated as I'd imagined, I don't know. > > Arnd, Michael, do you have any views on this? The minimal procedure would be to add it to mman-common.h, plus the asm/mman.h files for xtensa, mips, parisc and alpha, which all use a version that is compatible to a Unix variant, but that would be confusing the next person that needs to add a flag. I'd use the number 0x40000 for all architectures except alpha, because that makes the most sense for asm-generic/mman.h. Alpha is weird anyway here, so we don't need to avoid conflicts with it. With a few exceptions (sparc, powerpc), I think we should change all architectures to use asm-generic/mman.h instead of mman-common.h in the long run. If you touch those anyway, one option would be to do it in one step. Arnd <>< -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754943AbZIBIeu (ORCPT ); Wed, 2 Sep 2009 04:34:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753119AbZIBIeu (ORCPT ); Wed, 2 Sep 2009 04:34:50 -0400 Received: from moutng.kundenserver.de ([212.227.126.186]:52490 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752864AbZIBIet (ORCPT ); Wed, 2 Sep 2009 04:34:49 -0400 From: Arnd Bergmann To: Hugh Dickins Subject: Re: [PATCH 2/3] Add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions Date: Wed, 2 Sep 2009 10:34:40 +0200 User-Agent: KMail/1.12.0 (Linux/2.6.31-6-generic; KDE/4.3.0; x86_64; ; ) Cc: Eric B Munson , Mel Gorman , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, linux-man@vger.kernel.org, Michael Kerrisk , randy.dunlap@oracle.com References: <20090901130801.GB7995@us.ibm.com> In-Reply-To: X-Face: I@=L^?./?$U,EK.)V[4*>`zSqm0>65YtkOe>TFD'!aw?7OVv#~5xd\s,[~w]-J!)|%=]> =?utf-8?q?+=0A=09=7EohchhkRGW=3F=7C6=5FqTmkd=5Ft=3FLZC=23Q-=60=2E=60Y=2Ea=5E?= =?utf-8?q?3zb?=) =?utf-8?q?+U-JVN=5DWT=25cw=23=5BYo0=267C=26bL12wWGlZi=0A=09=7EJ=3B=5Cwg?= =?utf-8?q?=3B3zRnz?=,J"CT_)=\H'1/{?SR7GDu?WIopm.HaBG=QYj"NZD_[zrM\Gip^U MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200909021034.40827.arnd@arndb.de> X-Provags-ID: V01U2FsdGVkX19blNigrqrns4iVO+skcwvsf/GDyHvlYG9fekc DqIDUCi9foCH70ijm4GgMv+YtG8/uvP0SzIlM0hNVOCvH6bpue r52OqM2POel8UFOk1aNXw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 01 September 2009, Hugh Dickins wrote: > On Tue, 1 Sep 2009, Eric B Munson wrote: > > On Tue, 01 Sep 2009, Hugh Dickins wrote: > > > > > > That is explained by you #defining MAP_HUGETLB in include/asm-generic/ > > > mman-common.h to a number which is already being used for other MAP_s > > > on some architectures. That's a separate bug which needs to be fixed > > > by distributing the MAP_HUGETLB definition across various asm*/mman.h. > > > > Would it be okay to keep the define in include/asm-generic/mman.h > > if a value that is known free across all architectures is used? > > 0x080000 is not used by any arch and, AFAICT would work just as well. > > That's a very sensible suggestion, but departs from how we have > assigned new numbers up until now: so include/asm-generic/mman-common.h > isn't actually where we'd expect to find a Linux-specific MAP_ define. > > I'd say, yes, do that for now, so as not to hit this conflict while > testing in mmotm. But whether it should stay that way, or later the > arch/*/include/asm/mman.h's be updated as I'd imagined, I don't know. > > Arnd, Michael, do you have any views on this? The minimal procedure would be to add it to mman-common.h, plus the asm/mman.h files for xtensa, mips, parisc and alpha, which all use a version that is compatible to a Unix variant, but that would be confusing the next person that needs to add a flag. I'd use the number 0x40000 for all architectures except alpha, because that makes the most sense for asm-generic/mman.h. Alpha is weird anyway here, so we don't need to avoid conflicts with it. With a few exceptions (sparc, powerpc), I think we should change all architectures to use asm-generic/mman.h instead of mman-common.h in the long run. If you touch those anyway, one option would be to do it in one step. Arnd <>< From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id BD1A26B005A for ; Wed, 2 Sep 2009 04:34:56 -0400 (EDT) From: Arnd Bergmann Subject: Re: [PATCH 2/3] Add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions Date: Wed, 2 Sep 2009 10:34:40 +0200 References: <20090901130801.GB7995@us.ibm.com> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200909021034.40827.arnd@arndb.de> Sender: owner-linux-mm@kvack.org To: Hugh Dickins Cc: Eric B Munson , Mel Gorman , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, linux-man@vger.kernel.org, Michael Kerrisk , randy.dunlap@oracle.com List-ID: On Tuesday 01 September 2009, Hugh Dickins wrote: > On Tue, 1 Sep 2009, Eric B Munson wrote: > > On Tue, 01 Sep 2009, Hugh Dickins wrote: > > > > > > That is explained by you #defining MAP_HUGETLB in include/asm-generic/ > > > mman-common.h to a number which is already being used for other MAP_s > > > on some architectures. That's a separate bug which needs to be fixed > > > by distributing the MAP_HUGETLB definition across various asm*/mman.h. > > > > Would it be okay to keep the define in include/asm-generic/mman.h > > if a value that is known free across all architectures is used? > > 0x080000 is not used by any arch and, AFAICT would work just as well. > > That's a very sensible suggestion, but departs from how we have > assigned new numbers up until now: so include/asm-generic/mman-common.h > isn't actually where we'd expect to find a Linux-specific MAP_ define. > > I'd say, yes, do that for now, so as not to hit this conflict while > testing in mmotm. But whether it should stay that way, or later the > arch/*/include/asm/mman.h's be updated as I'd imagined, I don't know. > > Arnd, Michael, do you have any views on this? The minimal procedure would be to add it to mman-common.h, plus the asm/mman.h files for xtensa, mips, parisc and alpha, which all use a version that is compatible to a Unix variant, but that would be confusing the next person that needs to add a flag. I'd use the number 0x40000 for all architectures except alpha, because that makes the most sense for asm-generic/mman.h. Alpha is weird anyway here, so we don't need to avoid conflicts with it. With a few exceptions (sparc, powerpc), I think we should change all architectures to use asm-generic/mman.h instead of mman-common.h in the long run. If you touch those anyway, one option would be to do it in one step. Arnd <>< -- 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