[lug] uptimes

[Tkil]

>>>>> "Doug" == shawd  <shawd at pcisys.net> writes:

>> ralf at www:~$ uptime 
>> 4:11pm  up 90 days, 20:41,  3 users,  load average: 0.00, 0.00, 0.00
>> ralf at www:~$ ^D
>> 
>> the last one wrapped arround once!

Doug> What is it the overflow value for uptime in Linux?

it's about 500 days, IIRC.  it is a 32-bit unsigned value and it
counts jiffies (at 100Hz by default on x86).  which gives us:

| $ echo '2^32/(100*60*60*24)' | bc
| 497

Doug> I've seen RS/6000 AIX nodes that have been up for three years or
Doug> longer without overflowing their data types for uptime.

this might have been fixed in more recent versions of the kernel.