From owner-freebsd-arch Fri Oct 26 15:29:35 2001 Delivered-To: freebsd-arch@freebsd.org Received: from marlborough.cnchost.com (marlborough.concentric.net [207.155.248.14]) by hub.freebsd.org (Postfix) with ESMTP id 37FB437B401 for ; Fri, 26 Oct 2001 15:29:33 -0700 (PDT) Received: from bitblocks.com (adsl-209-204-185-216.sonic.net [209.204.185.216]) by marlborough.cnchost.com id SAA07928; Fri, 26 Oct 2001 18:29:30 -0400 (EDT) [ConcentricHost SMTP Relay 1.14] Message-ID: <200110262229.SAA07928@marlborough.cnchost.com> To: Poul-Henning Kamp Cc: Peter Wemm , arch@FreeBSD.ORG Subject: Re: 64 bit times revisited.. In-reply-to: Your message of "Fri, 26 Oct 2001 21:46:51 +0200." <6790.1004125611@critter.freebsd.dk> Date: Fri, 26 Oct 2001 15:29:30 -0700 From: Bakul Shah 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 > The problem is that people tend to think of time as integers > instead of a floating point value. Precisely! So what I am suggesting is to count in the smallest unit that makes sense on a machine. Associate the number of zoptoseconds (or whatever) per tick and add that to your 96 bit kernel time. So adjtime() will change that zs/tick count. When you need to create a file timestamp, divide by appropriate 10^N number to map it to the correct unit. I just can't believe that this operation is so frequent so as to require a micro (1/2^20) optimization. The two are not very differen but there is a lot less of rounding error given the number of decimal clocks in use: 10/100/1000Mhz ethernet, SONET(where 8K frames are sent per second) and so on. Since they (1/2^64 versus a min. unit of zoptosecond) are so similar either is fine with me as far as the kernel time is concerned. I was really more interested in what gets stored in a file inode. For that I would very strongly argue for an integer multiple of a basic time unit of ns instead of timespec or timeval. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message