Re: uptime reset after about 45 days

Gene Heskett
2003-10-31T13:20:12Z

On Friday 31 October 2003 05:37, Jakob Oestergaard wrote:
>On Fri, Oct 31, 2003 at 12:09:25AM +0100, Maciej Zenczykowski wrote:
>...
>
>> Uptime is stored in jiffies which is 32bit on your arch, which
>> results in an overflow after 2^32 clock ticks. TTTicks were 100 HZ
>> till recently (overflow after 470 or so days) now, they're 1000 ->
>> overflows after 45 days. Doesn't wreck anything except for uptime
>> display - known problem, not worth the trouble fixing it would
>> cause (64 bit values are non-atomic, unless MMX/SSE which isn't
>> allowed in kernel) - however there is (if I'm not mistaken) a
>> patch available wihich fixes this 'problem'.
>>
>> However since it is only a matter of uptime display...
>
>For me it would mean that I got disturbed or woken up by an SMS
> every 45 / (number_of_servers) = (low_number) days, because the
> monitoring system sees that a server suddenly has a 'suspiciously
> low' uptime.
>
>Fix the monitoring system to detect uptime wraps?
>
>Perhaps. It would be needed for Windows 95 as well, anyway.

Win95 needs more than an uptime patch at that point because the
keyboard is dead and only a reboot fixes it. We've been rebooting a
Win95 wire capture machine every 45-46 days on a schedule because of
that.

>Still, it's pretty darn pathetic to be required to include
> workarounds in *Linux* apps that would otherwise only be needed for
> '95.
>
>All in my humble oppinion of course.

--
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz 512M
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Copyright 2003 by Maurice Eugene Heskett, all rights reserved.