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Date:      Fri, 26 Oct 2001 15:29:30 -0700
From:      Bakul Shah <bakul@bitblocks.com>
To:        Poul-Henning Kamp <phk@critter.freebsd.dk>
Cc:        Peter Wemm <peter@wemm.org>, arch@FreeBSD.ORG
Subject:   Re: 64 bit times revisited.. 
Message-ID:  <200110262229.SAA07928@marlborough.cnchost.com>
In-Reply-To: Your message of "Fri, 26 Oct 2001 21:46:51 %2B0200." <6790.1004125611@critter.freebsd.dk> 

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> 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.

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