From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 20/25] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it Date: Thu, 12 May 2016 11:21:42 +0200 Message-ID: <2733875.IzutTZKHMc@wuerfel> References: <1459894127-17698-1-git-send-email-ynorov@caviumnetworks.com> <4989778.Fs81NJurjH@wuerfel> <20160512091758.GB11226@e104818-lin.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mout.kundenserver.de ([212.227.126.133]:49774 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752200AbcELJWu (ORCPT ); Thu, 12 May 2016 05:22:50 -0400 In-Reply-To: <20160512091758.GB11226@e104818-lin.cambridge.arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Catalin Marinas Cc: linux-doc@vger.kernel.org, Andrew Pinski , heiko.carstens@de.ibm.com, Yury Norov , Hanjun Guo , joseph@codesourcery.com, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, "jijun (D)" , Prasun.Kapoor@caviumnetworks.com, schwab@suse.de, agraf@suse.de, pinskia@gmail.com, klimov.linux@gmail.com, broonie@kernel.org, "Zhangjian (Bamvor)" , linux-arm-kernel@lists.infradead.org, Nathan_Lynch@mentor.com, linux-kernel@vger.kernel.org, Andrew Pinski , schwidefsky@de.ibm.com, christoph.muellner@theobroma-systems.com On Thursday 12 May 2016 10:17:58 Catalin Marinas wrote: > On Wed, May 11, 2016 at 09:30:07PM +0200, Arnd Bergmann wrote: > > On Wednesday 11 May 2016 17:59:01 Catalin Marinas wrote: > > > > I don't think the shifts are a problem, the main downside would be > > the limit to 44 bits of file offsets (16TB files), but it's also > > unclear if that is a practical problem at all. If it is, we run > > into the same problem on all other 32-bit architectures too. > > I hope people are seriously thinking of moving to an LP64 ABI if they > have such large file offset needs. Good point. 44 bits of file size is certainly enough for mmap() on a 32-bit task: you would only be able to map a very small fraction of the file anyway, and if you want to map larger files, and should move to 64-bit tasks long before this becomes a limitation. Arnd