From owner-freebsd-questions  Wed May 16  1:28:57 2001
Delivered-To: freebsd-questions@freebsd.org
Received: from tisch.mail.mindspring.net (tisch.mail.mindspring.net [207.69.200.157])
	by hub.freebsd.org (Postfix) with ESMTP
	id 96D7837B423; Wed, 16 May 2001 01:28:51 -0700 (PDT)
	(envelope-from tlambert2@mindspring.com)
Received: from mindspring.com (pool0141.cvx7-bradley.dialup.earthlink.net [209.178.164.141])
	by tisch.mail.mindspring.net (8.9.3/8.8.5) with ESMTP id EAA19088;
	Wed, 16 May 2001 04:28:48 -0400 (EDT)
Message-ID: <3B023A55.D8E21C03@mindspring.com>
Date: Wed, 16 May 2001 01:29:09 -0700
From: Terry Lambert <tlambert2@mindspring.com>
Reply-To: tlambert2@mindspring.com
X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony}  (Win98; U)
X-Accept-Language: en
MIME-Version: 1.0
To: Matt Dillon <dillon@earth.backplane.com>
Cc: dave <dleimbac@earthlink.net>, freebsd-questions@FreeBSD.ORG,
	arch@FreeBSD.ORG
Subject: Re: Gettimeofday Again...
References: <200105150337.UAA19677@gull.mail.pas.earthlink.net> <200105150346.f4F3kLE45720@earth.backplane.com> <3B00EF40.A1232B75@mindspring.com> <200105151737.f4FHbBL55271@earth.backplane.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: owner-freebsd-questions@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

Matt Dillon wrote:
> :The gettimeofday() calls were _the_ major useless overhead,
> :until I eliminated them by creating a zero system call version
> 
>     Terry, to be blunt... if you need performance you don't go
>     making superfluous system calls for every transaction.  If
>     you want marketing eye candy, all you need to do is a
>     statistical measurement... do fine measurement of 10% of
>     the transactions rather then fine measurement of 100% of
>     the transaction, and you are done.
> 
>     Also, using gettimeofday() is a ridiculous way to measure
>     fine grained time billions of times in production code.  I
>     mean, sure, it works... but getitimer() is about 5 times
>     faster.

I didn't need it for elapsed time measurements, I needed
it for log timestamps, so getitimer() would be useless.

BTW... to be blunt, gettimeofday() wouldn't be _the_ major
useless overhead, if I were making superfluous system calls.

;^).

-- Terry

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message