From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751755AbWBWRXP (ORCPT ); Thu, 23 Feb 2006 12:23:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751757AbWBWRXP (ORCPT ); Thu, 23 Feb 2006 12:23:15 -0500 Received: from terminus.zytor.com ([192.83.249.54]:50660 "EHLO terminus.zytor.com") by vger.kernel.org with ESMTP id S1751755AbWBWRXO (ORCPT ); Thu, 23 Feb 2006 12:23:14 -0500 Message-ID: <43FDEF72.5050200@zytor.com> Date: Thu, 23 Feb 2006 09:22:58 -0800 From: "H. Peter Anvin" User-Agent: Mozilla Thunderbird 1.0.7-1.1.fc4 (X11/20050929) X-Accept-Language: en-us, en MIME-Version: 1.0 To: starvik@axis.com, geert@linux-m68k.org, zippel@linux-m68k.org CC: dev-etrax@axis.com, linux-m68k@vger.kernel.org, linux-kernel , Ralf Baechle Subject: The sys_mmap2 syscall on m68k, cris, and mips Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, sorry for the wide distribution; I am trying to track down the story on the sys_mmap2 system call. Currently, to the best of my knowledge, glibc, µClibc, and klibc (haven't looked at newlib recently) all assume that sys_mmap2() is the way to map large files on 32-bit architectures, and that the offset argument is always shifted over by 12. As indicated by this post, this is the case on most architectures: http://marc.theaimsgroup.com/?l=linux-kernel&m=114066586932670&w=2 The odd ones out are m68k, cris, and MIPS. Ralf Baechle has indicated that non-4K-pages are currently experimental on MIPS, and that he would be open to changing MIPS to fit the rest of the pattern. That leaves m68k and cris. Thus, I would like to hear your opinion. One opinion is to define that the shift is fixed, but architecture-specific, and introduce an MMAP2_PAGE_SHIFT #define that libraries can pick up. (That would require m68k to change at least on the Sun3 platform, though. I don't think there is a huge installed base there, though.) -hpa