Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 19 Dec 2014 19:49:28 +0000
From:      "Poul-Henning Kamp" <phk@phk.freebsd.dk>
To:        Jilles Tjoelker <jilles@stack.nl>
Cc:        "freebsd-arch@freebsd.org" <arch@freebsd.org>, Adrian Chadd <adrian@freebsd.org>
Subject:   Re: Change default VFS timestamp precision?
Message-ID:  <82507.1419018568@critter.freebsd.dk>
In-Reply-To: <20141219194800.GA29107@stack.nl>
References:  <201412161348.41219.jhb@freebsd.org> <77322.1418933100@critter.freebsd.dk> <77371.1418933642@critter.freebsd.dk> <7567696.mqJ3jgzJgL@ralph.baldwin.cx> <82135.1419010861@critter.freebsd.dk> <20141219194800.GA29107@stack.nl>

next in thread | previous in thread | raw e-mail | index | archive | help
--------
In message <20141219194800.GA29107@stack.nl>, Jilles Tjoelker writes:
>On Fri, Dec 19, 2014 at 05:41:01PM +0000, Poul-Henning Kamp wrote:
>> In message <7567696.mqJ3jgzJgL@ralph.baldwin.cx>, John Baldwin writes:
>
>> >Yes, and multiplication is cheaper than division.  It's not a power of
>> >two (so more than a single bitshift), but possibly in the noise compared
>> >to the work in bintime() itself.
>
>> But why not use nanosecond resolution given that the cost is cheaper ?
>
>Because there is no API to set timestamps with nanosecond resolution,
>and therefore a cp -p copy of a file will appear older than the original
>with 99.9% probability. I think that is undesirable.

Hmm, good point, I forgot about that screwup...

-- 
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.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?82507.1419018568>