From owner-freebsd-arch Wed May 24 11:17:26 2000 Delivered-To: freebsd-arch@freebsd.org Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by hub.freebsd.org (Postfix) with ESMTP id 6889B37B87F for ; Wed, 24 May 2000 11:17:23 -0700 (PDT) (envelope-from gallatin@cs.duke.edu) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.9.3/8.9.3) with ESMTP id OAA20777; Wed, 24 May 2000 14:17:23 -0400 (EDT) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.9.3/8.9.1) id OAA22104; Wed, 24 May 2000 14:16:52 -0400 (EDT) (envelope-from gallatin@cs.duke.edu) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Wed, 24 May 2000 14:16:52 -0400 (EDT) To: Chuck Paterson Cc: arch@freebsd.org Subject: Re: Preemptive kernel on older X86 hardware In-Reply-To: <200005241800.MAA07427@berserker.bsdi.com> References: <200005241800.MAA07427@berserker.bsdi.com> X-Mailer: VM 6.43 under 20.4 "Emerald" XEmacs Lucid Message-ID: <14636.7064.775632.285834@grasshopper.cs.duke.edu> Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Chuck Paterson writes: > } > }If this isn't possible on an x86, please don't laugh too hard. I > }really don't know much about low-level x86 details. > } > }Cheers, > } > }Drew > > It can be done. In BSD/OS and Solaris however the locks must > be gotten because they are what protect from interrupt service. > Err... But I wasn't advocating removing the locks. I was suggesting having the routine patch in the correct locking code (or calls thereto) based on the processor type at the first invocation of each mutex. This way we could have a GENERIC kernel with the correct locking code for both 3/486 and modern x86 processors compiled in without the overhead of doing the processor type check on every call. Sorry if I wasn't clear.. Drew ------------------------------------------------------------------------------ Andrew Gallatin, Sr Systems Programmer http://www.cs.duke.edu/~gallatin Duke University Email: gallatin@cs.duke.edu Department of Computer Science Phone: (919) 660-6590 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message