From owner-cvs-all Mon Jan 15 13:35: 3 2001 Delivered-To: cvs-all@freebsd.org Received: from meow.osd.bsdi.com (meow.osd.bsdi.com [204.216.28.88]) by hub.freebsd.org (Postfix) with ESMTP id 5DB3F37B6A6; Mon, 15 Jan 2001 13:34:36 -0800 (PST) Received: from laptop.baldwin.cx (john@jhb-laptop.osd.bsdi.com [204.216.28.241]) by meow.osd.bsdi.com (8.11.1/8.9.3) with ESMTP id f0FLX2193638; Mon, 15 Jan 2001 13:33:02 -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: <200101152125.f0FLPis60113@aslan.scsiguy.com> Date: Mon, 15 Jan 2001 13:34:34 -0800 (PST) From: John Baldwin To: "Justin T. Gibbs" Subject: Re: cvs commit: src/sys/i386/conf GENERIC Cc: Bruce Evans , cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org, Wilko Bulte , Poul-Henning Kamp , Peter Wemm Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 15-Jan-01 Justin T. Gibbs wrote: >>See those 'cli' and 'popfl' instrucitons? Those are _privileged_. Userland >>can't disable/enable interrupts, so we have to trap into the kernel to do >>this >>no matter what. > > All that is required in the userland implementation is the setting of a > flag so the userland thread scheduler does not perform a thread switch. > Having an interrupt fire does not have the same consequences on a userland > program as it does for the kernel. Actually, the process needs to not be switched. This is part of KSE, so you would have to set a kernel flag in the kse for this, but yes, that would work. Granted, it pessimizes the non-i386 case, but not that badly. The kernel trap to emulate only pessimizes the i386 case (though the 386 could do without extra pessimizations, and it is a bigger pessimization.) -- 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 cvs-all" in the body of the message