From owner-freebsd-stable@FreeBSD.ORG Fri May 20 18:55:58 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 655C416A4CE; Fri, 20 May 2005 18:55:58 +0000 (GMT) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id AB83243D95; Fri, 20 May 2005 18:55:57 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.13.1/8.13.3) id j4KItvFc078543; Fri, 20 May 2005 13:55:57 -0500 (CDT) (envelope-from dan) Date: Fri, 20 May 2005 13:55:56 -0500 From: Dan Nelson To: Kris Kennaway Message-ID: <20050520185556.GB51092@dan.emsphone.com> References: <20050515120007.GA777@obiwan.tataz.chchile.org> <20050518155130.H87264@carver.gumbysoft.com> <20050519125639.GK818@obiwan.tataz.chchile.org> <20050520080435.GB26938@cell.sick.ru> <20050520131031.GU818@obiwan.tataz.chchile.org> <20050520131536.GA30219@cell.sick.ru> <20050520183738.GA53549@xor.obsecurity.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050520183738.GA53549@xor.obsecurity.org> X-OS: FreeBSD 5.4-STABLE X-message-flag: Outlook Error User-Agent: Mutt/1.5.9i cc: Jeremie Le Hen cc: Gleb Smirnoff cc: freebsd-stable@freebsd.org Subject: Re: panic in recent RELENG_5 tcp code path X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 May 2005 18:55:58 -0000 In the last episode (May 20), Kris Kennaway said: > On Fri, May 20, 2005 at 05:15:36PM +0400, Gleb Smirnoff wrote: > > On Fri, May 20, 2005 at 03:10:32PM +0200, Jeremie Le Hen wrote: > > J> I'm going to recompile my kernel with INVARIANTS but I wonder in > > J> which order of magniture it will slow my kernel down. In other > > J> words, what does INVARIANTS do concretely, shall I expect a > > J> performance drop like WITNESS does ? > > > > No. The performance loss is _much_ less significant than in WITNESS > > case. You probably will not notice it. > > Actually, INVARIANTS causes about a 10% penalty on wall clock time on > 5.x and above. Which is a lot less of a hit than WITNESS is, to be sure. WITNESS is like walking in mud :) Do you know if INVARIANT_SUPPORT by itself is enough to cause the 10% slowdown? That turns on LOCK_DEBUG, which in turn disables inlining of mutex macros. -- Dan Nelson dnelson@allantgroup.com