From owner-freebsd-smp Sun Jan 21 13:30: 5 2001 Delivered-To: freebsd-smp@freebsd.org Received: from moby.geekhouse.net (moby.geekhouse.net [64.81.6.36]) by hub.freebsd.org (Postfix) with ESMTP id B970937B402 for ; Sun, 21 Jan 2001 13:29:46 -0800 (PST) Received: from laptop.baldwin.cx (john@dhcp150.geekhouse.net [192.168.1.150]) by moby.geekhouse.net (8.11.0/8.9.3) with ESMTP id f0LLY8s78497; Sun, 21 Jan 2001 13:34:08 -0800 (PST) (envelope-from jhb@FreeBSD.org) 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: Date: Sun, 21 Jan 2001 13:29:41 -0800 (PST) From: John Baldwin To: Dag-Erling Smorgrav Subject: Re: debug.witness_skipspin Cc: smp@FreeBSD.org Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On 21-Jan-01 Dag-Erling Smorgrav wrote: > Dag-Erling Smorgrav writes: >> Is there a particular reason why this sysctl is read-only? Just for >> laughs, I built a kernel with a writeable debug.witness_skipspin, and >> experienced no ill effects from switching back and forth. > > Hey, I seem to have a thing with stupid questions today. Making it > writeable doesn't make a difference because all the spin locks are > already initialized (and enrolled or not) before you even get a chance > to toggle it. Nothing beats reading the source... I think skipspin causes it to not do extra checking during enter/exit though. -- John Baldwin -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message