From owner-cvs-all Mon Jan 15 13:43:59 2001 Delivered-To: cvs-all@freebsd.org Received: from pcnet1.pcnet.com (pcnet1.pcnet.com [204.213.232.3]) by hub.freebsd.org (Postfix) with ESMTP id 3454137B404; Mon, 15 Jan 2001 13:43:32 -0800 (PST) Received: (from eischen@localhost) by pcnet1.pcnet.com (8.8.7/PCNet) id QAA19784; Mon, 15 Jan 2001 16:43:08 -0500 (EST) Date: Mon, 15 Jan 2001 16:43:08 -0500 (EST) From: Daniel Eischen To: John Baldwin Cc: "Justin T. Gibbs" , Bruce Evans , cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org, Wilko Bulte , Poul-Henning Kamp , Peter Wemm Subject: Re: cvs commit: src/sys/i386/conf GENERIC In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 15 Jan 2001, John Baldwin wrote: > > 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.) I wouldn't want to set anything that tells the kernel not to switch the process (or KSE). That shouldn't be allowed from userland, at least without proper permissions. -- Dan Eischen To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message