From owner-freebsd-arch Fri Sep 20 13: 5:39 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 70A9137B401 for ; Fri, 20 Sep 2002 13:05:38 -0700 (PDT) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.FreeBSD.org (Postfix) with ESMTP id 314A343E65 for ; Fri, 20 Sep 2002 13:05:38 -0700 (PDT) (envelope-from baka@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1921) id 048ECAE03F; Fri, 20 Sep 2002 13:05:38 -0700 (PDT) Date: Fri, 20 Sep 2002 13:05:37 -0700 From: Jon Mini To: Julian Elischer Cc: Terry Lambert , Daniel Eischen , Bill Huey , freebsd-arch@FreeBSD.ORG Subject: Re: New Linux threading model Message-ID: <20020920200537.GZ24394@elvis.mu.org> References: <20020920191244.GY24394@elvis.mu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Julian Elischer [julian@elischer.org] wrote : > > > One exception is the use > > > "futex" wakeup in order to improve thread joins: FreeBSD should > > > look closely at this. > > > > "Futexes" are not new. We had this at Be, but we called them Bennaphores. > > > after "Ben"? Bennoit Schillings. He's french, so I'm probably spelling his last name wrong. He came up with the idea, so we named it after him. It addressed the very important issue that all semaphores in BeOS were kernel semaphores (BeOS used 1:1 threading) and 99% of the time (or worse) obtaining a semaphore didn't contend. So we wrapped the kernel sems with an atomic int. One nice thing about KSE is that all locking operations can be done in userland, and it saves a lot of this mess. -- Jonathan Mini http://www.freebsd.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message