From owner-freebsd-arch Tue Jan 1 14:34:30 2002 Delivered-To: freebsd-arch@freebsd.org Received: from srv1.cosmo-project.de (srv1.cosmo-project.de [213.83.6.106]) by hub.freebsd.org (Postfix) with ESMTP id BDB0237B429; Tue, 1 Jan 2002 14:34:26 -0800 (PST) Received: (from uucp@localhost) by srv1.cosmo-project.de (8.11.6/8.11.6) with UUCP id g01MYOA71737; Tue, 1 Jan 2002 23:34:24 +0100 (CET) (envelope-from ticso@cicely9.cicely.de) Received: from mail.cicely.de (cicely20.cicely.de [10.1.1.22]) by cicely5.cicely.de (8.12.1/8.12.1) with ESMTP id g01MHstx038121; Tue, 1 Jan 2002 23:17:54 +0100 (CET)?g (envelope-from ticso@cicely9.cicely.de) Received: from cicely9.cicely.de (cicely9.cicely.de [10.1.7.11]) by mail.cicely.de (8.11.0/8.11.0) with ESMTP id g01MHrW11250; Tue, 1 Jan 2002 23:17:53 +0100 (CET) Received: (from ticso@localhost) by cicely9.cicely.de (8.11.6/8.11.6) id g01MHrj10719; Tue, 1 Jan 2002 23:17:53 +0100 (CET) (envelope-from ticso) Date: Tue, 1 Jan 2002 23:17:52 +0100 From: Bernd Walter To: Mike Smith Cc: arch@FreeBSD.ORG Subject: Re: When to use atomic_ functions? (was: 64 bit counters) Message-ID: <20020101221752.GA10614@cicely9.cicely.de> References: <20020101213033.GB9899@cicely9.cicely.de> <200201012201.g01M1nr02027@mass.dis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200201012201.g01M1nr02027@mass.dis.org> User-Agent: Mutt/1.3.24i X-Operating-System: FreeBSD cicely9.cicely.de 5.0-CURRENT alpha 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 On Tue, Jan 01, 2002 at 02:01:49PM -0800, Mike Smith wrote: > > On Tue, Jan 01, 2002 at 12:48:34PM -0800, Mike Smith wrote: > > > > MBs are not needed for the variable itself, but they are making this > > > > family of functions very expensive. > > > > It's not very wise to handle counters with atomic_ functions unless > > > > the need to have MBs in them is not removed. > > > > > > It's imperative to use atomic operations for counters on SMP systems. > > > > But there is absolutely no need for MBs just to handle counters. > > So fix the atomic functions on the Alpha so that the mb's are only > present when the cache-related semantics (acquire/release) are specified. Ah - that makes sense now. Thanks. -- B.Walter COSMO-Project http://www.cosmo-project.de ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message