From owner-freebsd-arch Fri Oct 26 11: 0:19 2001 Delivered-To: freebsd-arch@freebsd.org Received: from agamemnon.cnchost.com (agamemnon.cnchost.com [207.155.252.31]) by hub.freebsd.org (Postfix) with ESMTP id E037837B405 for ; Fri, 26 Oct 2001 11:00:17 -0700 (PDT) Received: from bitblocks.com (adsl-209-204-185-216.sonic.net [209.204.185.216]) by agamemnon.cnchost.com id NAA14223; Fri, 26 Oct 2001 13:59:53 -0400 (EDT) [ConcentricHost SMTP Relay 1.14] Message-ID: <200110261759.NAA14223@agamemnon.cnchost.com> To: Alfred Perlstein Cc: Poul-Henning Kamp , Julian Elischer , Terry Lambert , Peter Wemm , arch@FreeBSD.ORG Subject: Re: 64 bit times revisited.. In-reply-to: Your message of "Fri, 26 Oct 2001 12:35:26 CDT." <20011026123526.F15052@elvis.mu.org> Date: Fri, 26 Oct 2001 10:59:53 -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 > Excuse me for being daft, but isn't some of the resolution currently > in the on-disk portion more than the time it takes to write and > re-read the data from most media? Are you concerned with faster > media? Perhaps MFS? Depends on *when* a file is timestamped. If the timestamp is done after the write has been pushed to the disk and confirmed as having written then you are right. If it is timestamped when a file operation has been completed and write queued to the disk driver, it is conceivable timestamps may be just a few hundreds of ns apart on even today's machines. If files are written by two different machines to two different filesystems (but they are related in make's eyes) their timestamps may be arbitrarily close but as I indicated in my previous email distributed systems bring their own set of problems which get exacerbated as you use finer time resolution. -- bakul To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message