[LEAPSECS] Good description of Linux kernel bugs related to leap seconds

[Hal Murray]

>From Steven Bellovin, on NANOG:

  See http://landslidecoding.blogspot.com/2012/07/linuxs-leap-second-deadlocks
.html

I've been hoping somebody would post a good summary like that.  It covers 5 
different bugs.

I'd split them into 3 clumps.  The first clump is kernel deadlocks.  As often 
happens with hard problems, fixing it here breaks it over there.  That's the 
first 3 bugs.

The 4th bug explains the CPU load spikes.  A kernel bug broke futex-es.  They 
are typically used in spin-lock like loops from user code.  I don't 
understand the details.  Setting the time (to any value) fixes the kernel 
problem so everything starts to work normally again.  (No need to reboot.)

The 5th bug is still a mystery.


Also from NANOG:

> If folks have not read it, I would suggest reading Normal Accidents by

> Charles Perrow.


I agree.  This is a good excuse to find my copy and read it again.  Yes, it's 
very good, but not directly related to leap seconds.



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