Re: settimeofday function taking 24 - 30 minutes to complete

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

M. Warner Losh wrote:
> In message: <45889598.3030408_at_u.washington.edu>
>             Garrett Cooper <youshi10_at_u.washington.edu> writes:
> : Scot Hetzel wrote:
> : > On 12/19/06, Mark Kirkwood <markir_at_paradise.net.nz> wrote:
> : >> Mark Kirkwood wrote:
> : >>
> : >> > Just tried out this on 6-STABLE
> : >>
> : >> > I can't get the hang at all (with or without thee extra includes):
> : >> >
> : >> > # time ./settimetest
> : >> > INFO: Saved current time
> : >> > INFO: settimeofday completed sucessfully
> : >> > INFO: Reset time to original value
> : >> > 0.000u 0.002s 0:00.00 0.0%      0+0k 0+0io 0pf+0w
> : >> >
> : >>
> : >> Oops - thought I was reading -stable instead of -current list
> : >> (doh).. sorry! Well at least you know it can work on *some* version of
> : >> FreeBSD!....(I don't have any machines running -current at the moment to
> : >> test).
> : >>
> : >
> : > Here's the time for the test on FreeBSD/amd64 -CURRENT, update yesterday.
> : >
> : > hp010# date ; time ./t1 ; date
> : > Tue Dec 19 19:07:33 CST 2006
> : > INFO: Saved current time
> : > INFO: settimeofday completed sucessfully
> : > INFO: Reset time to original value
> : > 0.000u 1469.241s 0:00.00 0.0%   5+175k 0+0io 0pf+0w
> : > Tue Dec 19 19:07:33 CST 2006
> : > hp010# date 200612191933
> : > Tue Dec 19 19:33:00 CST 2006
> : >
> : > Scot
> : Well, I'll find a random unused machine, setup FreeBSD on it with vmware 
> : and then try that out. Seems interesting that it takes 30 minutes to run 
> : instead of being done almost instantaneously.
> 
> It does run almost instantly if you use a time from 2000.  The date
> command also causes the lockup if you say 'date 1970010100140' as
> well.  Looks like there's a loop in the kernel to do division, but I
> can't quite find where it is.
> 
> If you have a good test setup, maybe you can do a binary search in the
> settimeofday code to find why a large leap backwards causes problems. 
> 
> Warner

	Why not just enabling debugging in the kernel and your source, and step
through a much as possible using gdb to find the problem?
	Finally got back to installing FBSD in a virtual machine, so I could
figure out where you are in current :D. The only other problem is that I
don't have a 64-bit box and you do..
- -Garrett
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (FreeBSD)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFFigGTEnKyINQw/HARAmy4AJ46UUe0d4czoqWn0o8nUSCgFQXhawCfV4pv
lbsH583vT7zn9VGSUSa+9TI=
=SCBA
-----END PGP SIGNATURE-----