From owner-freebsd-arch Fri Oct 26 9:11:54 2001 Delivered-To: freebsd-arch@freebsd.org Received: from InterJet.elischer.org (c421509-a.pinol1.sfba.home.com [24.7.86.9]) by hub.freebsd.org (Postfix) with ESMTP id 6E6E337B406 for ; Fri, 26 Oct 2001 09:11:51 -0700 (PDT) Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id KAA10933; Fri, 26 Oct 2001 10:34:35 -0700 (PDT) Date: Fri, 26 Oct 2001 10:34:33 -0700 (PDT) From: Julian Elischer To: Poul-Henning Kamp Cc: Peter Wemm , arch@FreeBSD.ORG Subject: Re: 64 bit times revisited.. In-Reply-To: <24137.1004080687@critter.freebsd.dk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 ok, so take 2 bits. that leaves you with 30 bits (1 nanosecond) resolution... or to be compatible... take it from the top 2 bits.. that leaves us with 400 years either way.. enough I'd say.. for file access times.. On Fri, 26 Oct 2001, Poul-Henning Kamp wrote: > In message , Jul > ian Elischer writes: > > >ufs has enough room to fix this.. > >there has been a field defined in the on disk inode for nanosecs > >in each of the time values... > >if we take the lowest 8 bits of that field and re-assign it to be > >the highest 8 bits of the seconds, then we have time accuracy down to > >microseconds still and we expand file times by a factor > >of 256 (which is all of recorded history plus some) > > > >we just always set those bits to 0 for the next 37 years and we don;t > >really lose time resolution and we gain compatibility with the future.. > >nothing these days has nonosecond resolution there anyhow.... > > "640K is enough for anybody" > > "There is no harm in tobacco" > > "Of course I'll respect you in the morning" > > etc > > etc > > Your proposal would leave us with quarter-microsecond resolution, > and I'm pretty sure I can beat that to pulp in the next 10 years > on a RAM disk... > > There is no harm in having to run a rev on the UFS/FFS on-disk format, > when you hav 37 years to complete it. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > phk@FreeBSD.ORG | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message