From owner-freebsd-hackers Thu Aug 9 4:22:23 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from iona.dcs.gla.ac.uk (iona.dcs.gla.ac.uk [130.209.240.35]) by hub.freebsd.org (Postfix) with ESMTP id 1FC5737B401 for ; Thu, 9 Aug 2001 04:22:21 -0700 (PDT) (envelope-from neugebar@dcs.gla.ac.uk) Received: from therese.dcs.gla.ac.uk ([130.209.241.134] helo=therese.dcs.gla.ac.uk.dcs.gla.ac.uk) by iona.dcs.gla.ac.uk with esmtp (Exim 3.13 #1) id 15UntM-0002eH-00; Thu, 09 Aug 2001 12:22:20 +0100 Received: by therese.dcs.gla.ac.uk.dcs.gla.ac.uk (8.11.3/Dumb) id f79BMFQ35472; Thu, 9 Aug 2001 12:22:15 +0100 (BST) To: Jeff Behl Cc: "'freebsd-hackers@freebsd.org'" Subject: Re: timing question References: <0307F3737A2AD511A42200D0B7A071919A4043@dopey.corp.expertcity.com> From: Rolf Neugebauer Date: 09 Aug 2001 12:22:14 +0100 In-Reply-To: Jeff Behl's message of "Wed, 8 Aug 2001 10:21:20 -0700" Message-ID: Lines: 15 User-Agent: Gnus/5.0805 (Gnus v5.8.5) Emacs/20.7 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Jeff Behl writes: > thanks to all for the help with the timing question. Increasing the hz to > 400 (in param.c) allowed for granularity of 5ms, which is what we needed. > For those as unknowing as I was about unix timing, I ran across the > following url which explained why a setting of 400hz allows for a max > resolution of twice the tick amount (2.5ms).: > http://www.ripe.net/ripencc/mem-services/ttm/Notes/PAM2001/node6.html#SECTIO > N00061000000000000000 You don't need to modify param.c. Just add options HZ=400 # increase timer frequency to your kernel config file. Rolf To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message