From owner-cvs-all Wed Feb 20 14:28:21 2002 Delivered-To: cvs-all@freebsd.org Received: from mail12.speakeasy.net (mail12.speakeasy.net [216.254.0.212]) by hub.freebsd.org (Postfix) with ESMTP id 8A95237B405 for ; Wed, 20 Feb 2002 14:27:34 -0800 (PST) Received: (qmail 11484 invoked from network); 20 Feb 2002 22:27:33 -0000 Received: from unknown (HELO laptop.baldwin.cx) ([65.90.117.57]) (envelope-sender ) by mail12.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 20 Feb 2002 22:27:33 -0000 Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <200202131847.g1DIlp851160@freefall.freebsd.org> Date: Wed, 20 Feb 2002 17:27:36 -0500 (EST) From: John Baldwin To: Alfred Perlstein Subject: RE: cvs commit: src/sys/i386/conf GENERIC Cc: cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On 13-Feb-02 Alfred Perlstein wrote: > alfred 2002/02/13 10:47:51 PST > > Modified files: > sys/i386/conf GENERIC > Log: > Re-enable WITNESS for GENERIC. Since the 5.x branch is mostly about > SMP we'd like as much feedback as possible from users about possible > locking problems as early as possible. > > To negate most of the performance impact I've also enabled > WITNESS_SKIPSPIN. I've done this as we've been running WITNESS > over the spinlock code for a while without incident and it goes a > long way to making the performance problems of WITNESS much more > bearable. Actually, there are problems with teh clock lock and sched lock on alpha. :) > Users who should be running current should know about turning WITNESS > off for performance reasons. > > That said and done, WITNESS could/should be made into a tuneable, > but we'll leave that as an excersize to those that want to disable > it without a kernel recompile. set debug.witness_watch=0 WITNESS_SKIPSPIN is also a tunable and is documented as such in witness(4). debug.witness_watch isn't documented in witness(4) but should be. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message