From owner-freebsd-arch@FreeBSD.ORG Wed Sep 24 04:45:59 2008 Return-Path: Delivered-To: arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DD11A1065678; Wed, 24 Sep 2008 04:45:59 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id 9AA6E8FC1B; Wed, 24 Sep 2008 04:45:59 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.2/8.14.1) with ESMTP id m8O4ipwX059544; Tue, 23 Sep 2008 22:44:53 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Tue, 23 Sep 2008 22:45:37 -0600 (MDT) Message-Id: <20080923.224537.-957831121.imp@bsdimp.com> To: jhein@timing.com From: "M. Warner Losh" In-Reply-To: <18641.24692.875414.533794@gromit.timing.com> References: <18641.9342.134166.77425@gromit.timing.com> <200809171321.45354.jhb@freebsd.org> <18641.24692.875414.533794@gromit.timing.com> X-Mailer: Mew version 5.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: arch@freebsd.org Subject: Re: 64 bit time_t X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Sep 2008 04:46:00 -0000 In message: <18641.24692.875414.533794@gromit.timing.com> John Hein writes: : John Baldwin wrote at 13:21 -0400 on Sep 17, 2008: : > On Wednesday 17 September 2008 11:38:38 am John Hein wrote: : > > John Baldwin wrote at 10:40 -0400 on Sep 17, 2008: : > > > And with amd64/x86-64, it may prove to not really be necessary. : > > : > > I'm not sure I understand the "may" part. Aren't we already using 64 : > > bit time_t natively on amd64? Or maybe you're talking about 32 bit : > > compat on amd64. : > : > Yes, we are, and as newer server-class machines (at least) are predominantly : > 64-bit, for at least the server-class market it would seem that boxes will : > probably move to an amd64 kernel with a 64-bit time_t w/o requiring lots of : > rototilling to support 64-bit time_t on i386. : : Right. I'm more concerned with planning now for y2038 on 32-bit : embedded boxes that may still be around in 30 years. In this case, I : think it's easy enough for me to just change my local FreeBSD tree to : have time_t be 64 bit and recompile. : : But that doesn't help those users desperately clinging to their : 7.1-RELEASE i386 boxes 30 years from now ;) It won't be on FreeBSD/arm embedded boxes :-) When we changed from 32-bit to 64-bit on arm, it wasn't a huge deal. If you don't care about ABI compatibility, then it is a simple matter of changing the definition of __time_t in sys/i386/include/_types.h and rebuilding. After all, there's no binaries not built as part of the controlled build process that you use in certain embedded boxes that I think you might be talking about ;-0. All that system call and ioctl and structure compat stuff is interesting, but just not relevant to your problem domain... Warner