From owner-freebsd-arch Fri Oct 26 14:13:18 2001 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 41DE637B406; Fri, 26 Oct 2001 14:13:12 -0700 (PDT) Received: (from dillon@localhost) by apollo.backplane.com (8.11.6/8.9.1) id f9QLDBJ38657; Fri, 26 Oct 2001 14:13:11 -0700 (PDT) (envelope-from dillon) Date: Fri, 26 Oct 2001 14:13:11 -0700 (PDT) From: Matthew Dillon Message-Id: <200110262113.f9QLDBJ38657@apollo.backplane.com> To: John Baldwin , Poul-Henning Kamp , arch@FreeBSD.ORG, Peter Wemm , Bakul Shah Subject: Re: 64 bit times revisited.. References: <200110262108.f9QL8n238592@apollo.backplane.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 : : ::> ::> If you look in sys/kern/kern_tc.c you can see how much extra ::> gunk that results in, checking for overruns on the middle part and ::> whats not. ::> ::> There can be no doubt that the best timestamp representation is ::> pure binary, originating at the second, and that is how my proposal ::> is constructed: ::> ::> <-- 32bit --><-- 32bit --> . <-- 32bit --><-- 32bit --> ::> 1 2 3 4 :: ::IOW, a fixed-point number. This is definitely the optimal solution presented ::so far for the in-kernel time keeping, IMO. And I will also note that trying to represent both seconds and sub-seconds in a single fixed point integer is a real bad idea. It makes life unnecessarily difficult for the 95% of the code that only needs the seconds portion. Any fractional representation should be a SEPARATE field. We will have time_t, in seconds, and we can have struct ntm representing both the seconds and fractional portions (as separate fields). -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message