From owner-freebsd-arch Thu Jan 17 8:45: 0 2002 Delivered-To: freebsd-arch@freebsd.org Received: from prg.traveller.cz (prg.traveller.cz [193.85.2.77]) by hub.freebsd.org (Postfix) with ESMTP id 4286637B416 for ; Thu, 17 Jan 2002 08:44:50 -0800 (PST) Received: from prg.traveller.cz (localhost [127.0.0.1]) by prg.traveller.cz (8.12.1[KQ-CZ](1)/8.12.1/pukvis) with ESMTP id g0HGim4a061844 for ; Thu, 17 Jan 2002 17:44:48 +0100 (CET) Received: from localhost (mime@localhost) by prg.traveller.cz (8.12.1[KQ-CZ](1)/pukvis) with ESMTP id g0HGimLd061841 for ; Thu, 17 Jan 2002 17:44:48 +0100 (CET) Date: Thu, 17 Jan 2002 17:44:48 +0100 (CET) From: Michal Mertl To: arch@freebsd.org Subject: Re: 64 bit counters again Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 I promise that if there isn't anything new from you this is the last time I'm talking about it. I wan't to inform you that I tried to look at some system pushing data with different size/implementation network counters. I did my last test on dual PIII 750. I don't know, of any good way to measure the load, so I just run vmstat -w1 (and calculated average idle) while pushing the data and also looked at the throughput at 100Mbit Full-Duplex. System was performing about 10000 interrupts and 15000 packets per second. I didn't notice any difference between using 32 bits non atomic operations (3 clocks per op) or 64 bit atomic (lock;cmpxchg8b - 50 clocks). I did also measure it on single Duron 800 with the same result. It was TCP traffic so there were at least three classes of counters updated - interface, ip and tcp. Interface counters were rather cheap because fxp does updating only once per second but protocol were I think worse. Just a dumb guess is that there were 5 adds per packet so it means losing 15000*47*5=3525000 clocks. Judge by yourself. -- Michal Mertl mime@traveller.cz To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message