From owner-freebsd-hackers@FreeBSD.ORG Sun Mar 27 14:28:56 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CAA5016A4CE for ; Sun, 27 Mar 2005 14:28:56 +0000 (GMT) Received: from mailout01.sul.t-online.com (mailout01.sul.t-online.com [194.25.134.80]) by mx1.FreeBSD.org (Postfix) with ESMTP id D92A743D49 for ; Sun, 27 Mar 2005 14:28:55 +0000 (GMT) (envelope-from Alexander@Leidinger.net) Received: from fwd27.aul.t-online.de by mailout01.sul.t-online.com with smtp id 1DFYl4-0000kp-02; Sun, 27 Mar 2005 16:28:54 +0200 Received: from Andro-Beta.Leidinger.net (bjgs4kZeYe8eyG2pLKofxoV2N4Chvx2E4BKTUkY6lfIlNdfy6KkFEF@[217.229.215.79]) by fwd27.sul.t-online.de with esmtp id 1DFYkq-0iYkN60; Sun, 27 Mar 2005 16:28:40 +0200 Received: from Magellan.Leidinger.net (Magellan.Leidinger.net [192.168.1.1]) j2RERHI2057446; Sun, 27 Mar 2005 16:27:17 +0200 (CEST) (envelope-from Alexander@Leidinger.net) Date: Sun, 27 Mar 2005 16:28:39 +0200 From: Alexander Leidinger To: Avleen Vig Message-ID: <20050327162839.2fafa6aa@Magellan.Leidinger.net> In-Reply-To: <20050327134044.GM78512@silverwraith.com> References: <423C15C5.6040902@fsn.hu> <20050327133059.3d68a78c@Magellan.Leidinger.net> <20050327134044.GM78512@silverwraith.com> X-Mailer: Sylpheed-Claws 1.0.4 (GTK+ 1.2.10; i386-portbld-freebsd6.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-ID: bjgs4kZeYe8eyG2pLKofxoV2N4Chvx2E4BKTUkY6lfIlNdfy6KkFEF@t-dialin.net X-TOI-MSGID: a4c8febf-77c4-4532-880f-cfc975149a0d X-Mailman-Approved-At: Mon, 28 Mar 2005 12:50:29 +0000 cc: hackers@freebsd.org Subject: Re: 5-STABLE kernel build with icc broken X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 27 Mar 2005 14:28:56 -0000 On Sun, 27 Mar 2005 05:40:44 -0800 Avleen Vig wrote: > On Sun, Mar 27, 2005 at 01:30:59PM +0200, Alexander Leidinger wrote: > > > It seems to me that building kernel with icc is currently broken, at > > > least in 5-STABLE. Could somebody investigate this? > > > > I don't have a problem to compile it with a recent -current and a recent > > icc (-stable not tested), but the resulting kernel imediatly panics > > (page fault in _mtx_...()). > > Without intending to start any compiler holy wars, what benefits does > ICC provide over GCC for the end user? Various: - auto-vectorizer (no benefit for the kernel, since we can't use FPU/SIMD instructions at any time... yet (interested hackers can have a look how DragonFly handles it, I can provide the necessary commit logs)) - optimizations for Intel CPUs direct from the manufacturer of the CPU (they have a lot of interest to produce very fast code) - a different set of compiler warnings - better code quality (if is compilable by more than one compiler it may be more portable) Icc already pointed out some bad code (asm code in the IP checksumming code... DragonFly changed it already), and the panic as noticed above may also be an indication that we have some code in the tree which smells bad. Bye, Alexander. -- The dark ages were caused by the Y1K problem. http://www.Leidinger.net Alexander @ Leidinger.net GPG fingerprint = C518 BC70 E67F 143F BE91 3365 79E2 9C60 B006 3FE7