From owner-freebsd-arch Sun Feb 17 23:33:50 2002 Delivered-To: freebsd-arch@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 8120A37B400; Sun, 17 Feb 2002 23:33:48 -0800 (PST) Received: (from dillon@localhost) by apollo.backplane.com (8.11.6/8.9.1) id g1I7Xej12207; Sun, 17 Feb 2002 23:33:40 -0800 (PST) (envelope-from dillon) Date: Sun, 17 Feb 2002 23:33:40 -0800 (PST) From: Matthew Dillon Message-Id: <200202180733.g1I7Xej12207@apollo.backplane.com> To: Terry Lambert Cc: Bruce Evans , Poul-Henning Kamp , Julian Elischer , Alfred Perlstein , arch@FreeBSD.ORG, jhb@FreeBSD.ORG, peter@wemm.org, jake@locore.ca Subject: Re: gettimeofday() and crhold()/crfree() (was Re: gettimeofday()andcopyout().Is copyout() MPSAFE on non-i386 archs? ) References: <20020218151249.E4728-100000@gamplex.bde.org> <3C70AB8B.96589869@mindspring.com> 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 :.4nsec * 22,000 transactions/sec * 5 timestamps/transaction := 440us/sec spent on time stamps. : :Up that to 2uS and... = 220ms/sec on time stamps = ~1/4 of :all available time spent on time stamps. : :[ ... other stuff not really applicable; can discuss why : off list, if necessary ... ] : :-- Terry This is a meaningless exercise if you don't take into account everything the program in question is doing on a per transaction basis. To say that a single 2uS system call takes 25% of available resources also infers that all your other code requires only 6uS per transaction of overhead, which means it doesn't do very much eh? -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message