Groups > comp.os.linux.development.system > #354

Re: Getting time of last reboot on Linux

From	Ivan Shmakov <oneingray@gmail.com>
Newsgroups	comp.os.linux.development.system, comp.unix.programmer
Subject	Re: Getting time of last reboot on Linux
Date	2011-12-20 11:48 +0700
Organization	Aioe.org NNTP Server
Message-ID	<86zken7ssd.fsf@gray.siamics.net> (permalink)
References	<4c0afddf-5e6e-41f5-b8d2-b65afcc4ee29@z1g2000vbx.googlegroups.com> <RjqHq.27421$c27.19904@newsfe22.iad> <k5t4s8-sr2.ln1@wilbur.25thandClement.com>

Cross-posted to 2 groups.

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>>>>> William Ahern <william@wilbur.25thandClement.com> writes:

[...]

 > However, last time I inquired with Google, 32-bit Linux had a
 > wrapping issue with /proc/uptime (and presumably uptime(3)). The
 > uptime gives seconds, but is computed in jiffies, which has a much
 > higher resolution but overflows much faster--400-something days on
 > some 2.4 kernels.

	Indeed, I've had such a problem on one of my home systems once.

	Assuming the rate of 100 jiffies per second, it gives some 497
	days before the overflow.

(/ (expt 2 32)
   100.0 60 60 24)
=> 497.1026(962)

[...]

-- 
FSF associate member #7257

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Getting time of last reboot on Linux Alex Vinokur <alex.vinokur@gmail.com> - 2011-12-18 09:35 -0800
  Re: Getting time of last reboot on Linux Steve Thompson <smt@vgersoft.com> - 2011-12-18 12:46 -0500
    Re: Getting time of last reboot on Linux Alex Vinokur <alex.vinokur@gmail.com> - 2011-12-18 10:12 -0800
      Re: Getting time of last reboot on Linux Volker Birk <bumens@dingens.org> - 2011-12-18 18:19 +0000
        Re: Getting time of last reboot on Linux Andrew Smallshaw <andrews@sdf.lonestar.org> - 2011-12-21 16:01 +0000
  Re: Getting time of last reboot on Linux Volker Birk <bumens@dingens.org> - 2011-12-18 18:18 +0000
  Re: Getting time of last reboot on Linux Lew Pitcher <lpitcher@teksavvy.com> - 2011-12-18 13:31 -0500
    Re: Getting time of last reboot on Linux Stephane CHAZELAS <stephane_chazelas@yahoo.fr> - 2011-12-18 21:48 +0000
      Re: Getting time of last reboot on Linux Barry Margolin <barmar@alum.mit.edu> - 2011-12-18 21:29 -0500
        Re: Getting time of last reboot on Linux Stephane CHAZELAS <stephane_chazelas@yahoo.fr> - 2011-12-19 12:59 +0000
    Re: Getting time of last reboot on Linux William Ahern <william@wilbur.25thandClement.com> - 2011-12-19 15:15 -0800
      Re: Getting time of last reboot on Linux Lew Pitcher <lpitcher@teksavvy.com> - 2011-12-19 19:20 -0500
        Re: Getting time of last reboot on Linux William Ahern <william@wilbur.25thandClement.com> - 2011-12-19 18:32 -0800
        Re: Getting time of last reboot on Linux gordonb.xm1tg@burditt.org (Gordon Burditt) - 2011-12-22 00:16 -0600
          Re: Getting time of last reboot on Linux Stefan Monnier <monnier@iro.umontreal.ca> - 2012-01-09 09:18 -0500
      Re: Getting time of last reboot on Linux Ivan Shmakov <oneingray@gmail.com> - 2011-12-20 11:48 +0700
  Re: Getting time of last reboot on Linux Richard Kettlewell <rjk@greenend.org.uk> - 2011-12-21 17:06 +0000
    Re: Getting time of last reboot on Linux gazelle@shell.xmission.com (Kenny McCormack) - 2012-02-09 17:25 +0000
      Re: Getting time of last reboot on Linux Richard Kettlewell <rjk@greenend.org.uk> - 2012-02-09 21:11 +0000

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