Date: Tue, 1 Jan 2002 23:17:52 +0100 From: Bernd Walter <ticso@cicely9.cicely.de> To: Mike Smith <msmith@FreeBSD.ORG> Cc: arch@FreeBSD.ORG Subject: Re: When to use atomic_ functions? (was: 64 bit counters) Message-ID: <20020101221752.GA10614@cicely9.cicely.de> In-Reply-To: <200201012201.g01M1nr02027@mass.dis.org> References: <20020101213033.GB9899@cicely9.cicely.de> <200201012201.g01M1nr02027@mass.dis.org>
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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
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