Oliver Fromme wrote:
What's your problem? In your first mail you seemed to be
complaining that there isn't sufficient range and accuracy
in the time stamps. I explained to you that there is
indeed more accuracy than you thought, and now you complain
that there's too much of it?
I am in not complaining. Just wanted to talk about something, it's what
freebsd-chat is for. I raised a topic, we started talking about it. Let me
rework my comment, to get the more real meaning of it: IMO, that is redunant.
(Don't you think so?)
To answer your question: Modern hardware is already fast
enough that sub-microsecond accuracy is required. Also
keep in mind that it is undesirable to change the on-disk-
format of a file system every year. When the UFS2 format
was designed, it should be sufficient at least for the
needs of ten years in the future, possibly even more.
So the provision for nanosecond accuracy is not far off.
Don't know if I'm right, but in the hardware used nowadays, the time can change
every several hundred nanoseconds. That is, can represent every microsecond
with, say, 0.75 accuracy, for tens of microseconds that's 0.975, 0.9975 for
hundreds, and 0.99975 for milliseconds.
Ideally, two consecutive, non-parallel operations should
give two different timestamps. That applies to creating or
touching a file or other kind of resource, or even just
calling the gettimeofday() function from within the same
thread, or whatever. In reality that isn't the case today
for FreeBSD for other reasons, but the timestamp accuracy
of UFS2 would certainly be sufficient for that.
Actually, my intend wasn't to use it in filesystems, but server-client apps,
such as games, where 32bit integer timers must be restarted every 3 weeks
Giorgos Keramidas wrote:
> On 2007-03-25 01:36, [EMAIL PROTECTED] wrote:
>> Oliver Fromme wrote:
>>> FreeBSD's UFS2 already uses 96bit timestamps, where 64 bits are used
>>> for seconds and 32 bits are used for nanoseconds. Is that sufficient
>>> for you?
>> What the hell for?
>
> ``Just because it can.''
Good. :] 2x64bit for x64?
> Seriously now, please show some more respect to Oliver and the time he
> spent to research and write up a very informative reply. It's not very
> nice to post an original email like the one you posted, posing a
> relatively unintelligible question, and then reply ``what the hell
> for?'' to Oliver's email. At least *he* tried to find out something by
> reading the source, he wrote a reply with details pointers to places
> where you can find out more for yourself, and was enough of a gentleman
> to *avoid* using potentially offensive words.
>
> Let's be a little more cordial to the ones who help us, shall we?
And I appreciate your hard work trying to help me. Perhaps my comment was
somewhat offensive. I appologize.
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