Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263547AbTEIWKd (ORCPT ); Fri, 9 May 2003 18:10:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263548AbTEIWKc (ORCPT ); Fri, 9 May 2003 18:10:32 -0400 Received: from cpe-24-221-190-179.ca.sprintbbd.net ([24.221.190.179]:39572 "EHLO myware.akkadia.org") by vger.kernel.org with ESMTP id S263547AbTEIWK3 (ORCPT ); Fri, 9 May 2003 18:10:29 -0400 Message-ID: <3EBC2A3C.8040409@redhat.com> Date: Fri, 09 May 2003 15:22:52 -0700 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4b) Gecko/20030506 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Timothy Miller CC: linux-kernel@vger.kernel.org Subject: Re: hammer: MAP_32BIT References: <3EBB5A44.7070704@redhat.com> <20030509092026.GA11012@averell> <16059.37067.925423.998433@gargle.gargle.HOWL> <20030509113845.GA4586@averell> <3EBC0084.4090809@redhat.com> <3EBC15B5.4070604@zytor.com> <3EBC2164.6050605@redhat.com> <3EBC29A5.1050005@techsource.com> In-Reply-To: <3EBC29A5.1050005@techsource.com> X-Enigmail-Version: 0.75.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1388 Lines: 34 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Timothy Miller wrote: > If your program is capable of handling an address with more than 32 > bits, what point is there giving a hint? Either your program can handle > 64-bit pointers or it cannot. Any program flexible enough to handle > either size dynamically would expend enough overhead checking that it > would be worse than if it just made a hard choice. Look at the x86-64 context switching code. If memory addressed by the GDT entries has a 32-bit address it uses a different method than for cases where the virtual address has more than 32 bits. This way of handling GDT entries is faster according to ak. So, it's not a correctness thing, it's a performance thing. - -- - --------------. ,-. 444 Castro Street Ulrich Drepper \ ,-----------------' \ Mountain View, CA 94041 USA Red Hat `--' drepper at redhat.com `--------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQE+vCo82ijCOnn/RHQRAlGzAJ9Ti80kJMeecyxGikowWcfCAq0stwCfRVcQ Clui3Z6yKNSy3mu+phrY2FQ= =GFwi -----END PGP SIGNATURE----- - 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/