From owner-freebsd-current@FreeBSD.ORG Thu Apr 26 10:24:23 2007 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 7336A16A400 for ; Thu, 26 Apr 2007 10:24:23 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c220-239-3-125.belrs4.nsw.optusnet.com.au [220.239.3.125]) by mx1.freebsd.org (Postfix) with ESMTP id F1D7513C455 for ; Thu, 26 Apr 2007 10:24:22 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.13.8/8.13.8) with ESMTP id l3QAOLA4001773; Thu, 26 Apr 2007 20:24:21 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.13.8/8.13.8/Submit) id l3QAOLGF001772; Thu, 26 Apr 2007 20:24:21 +1000 (EST) (envelope-from peter) Date: Thu, 26 Apr 2007 20:24:21 +1000 From: Peter Jeremy To: Suleiman Souhlal Message-ID: <20070426102420.GA819@turion.vk2pj.dyndns.org> References: <20070423113400.GC28587@gw.humppa.dk> <2018ADA6-11D5-48D1-98BD-4397A60E14AF@FreeBSD.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="huq684BweRXVnRxX" Content-Disposition: inline In-Reply-To: <2018ADA6-11D5-48D1-98BD-4397A60E14AF@FreeBSD.org> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.14 (2007-02-12) Cc: current@freebsd.org Subject: Re: Suggestions on Avoiding syscall Overhead X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Apr 2007 10:24:23 -0000 --huq684BweRXVnRxX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2007-Apr-25 01:03:19 -0700, Suleiman Souhlal wrot= e: >IMHO, the main usage of the global readonly page is (apart from =20 >faster gettimeofday and similar) is that you can put the syscall =20 >entry function in it, and have the kernel choose at boot the most =20 >efficient method (INT 0x80 or SYSENTER/SYSCALL) based on what the CPU =20 >supports, while still having binaries that run everywhere. That's a nice idea. The only downside I see is that it means the page would need to be executable. I would prefer not to have data areas executable - even if they are read-only. I think that FreeBSD should make more use of CPU-specific coding to enhance performance. Maybe even something along the lines of Solaris where linking to libc implicitly links to a CPU-specific .so if it exists. >Similarly, I don't think getuid, geteuid, getpid,getgid, getegid, =20 >getpgrp are used enough to justify the work. Likewise. --=20 Peter Jeremy --huq684BweRXVnRxX Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFGMH3U/opHv/APuIcRAhiJAJ0acpN1zmpsv20RyEVifF8Dz+4dEACfUOXV eEp1OpNnq2yw3a17ZJa4ttg= =bs14 -----END PGP SIGNATURE----- --huq684BweRXVnRxX--