From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262324AbTEIHXJ (ORCPT ); Fri, 9 May 2003 03:23:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262326AbTEIHXJ (ORCPT ); Fri, 9 May 2003 03:23:09 -0400 Received: from cpe-24-221-190-179.ca.sprintbbd.net ([24.221.190.179]:18321 "EHLO myware.akkadia.org") by vger.kernel.org with ESMTP id S262324AbTEIHXH (ORCPT ); Fri, 9 May 2003 03:23:07 -0400 Message-ID: <3EBB5A44.7070704@redhat.com> Date: Fri, 09 May 2003 00:35:32 -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: linux-kernel@vger.kernel.org, Andi Kleen Subject: hammer: MAP_32BIT 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 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 To allocate stacks for the threads in nptl we currently use MAP_32BIT to make sure we get <4GB addresses for faster context switching time. But once the address space is allocated we have to resort to not using the flag. This means we have to make 2 mmap() calls, one with MAP_32BIT and if it fails another one without. It would be much better if there would also be a MAP_32PREFER flag with the appropriate semantics. The failing mmap() calls seems to be quite expensive so programs with many threads are really punished a lot. - -- - --------------. ,-. 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+u1pF2ijCOnn/RHQRAk2IAKDAzXZUOsxMPAKkK9ivOz8o6zAaHQCeMC24 ysih3QB/I1w5MNXEIxNs284= =2cet -----END PGP SIGNATURE-----