Massive load average spikes tracing the cause

From: Tyler Earman
Date: Sun Apr 24 2011 - 15:16:25 EST


Please CC me if you would.


Basically, I'm running a machine that will have massive load average
spikes (up into the 5-10 range on a 2 CPU machine) at seemingly random
intervals. I've tried most normal tracing conventions but now I'm
going to have to delve into the kernel to find out exactly what's
going on here.

The kernel does softlock occasionally on this event, but the CPU usage
stays very low (1-10%).

I'm guessing this is an I/O lockup somewhere, but the question is /where/.

So, in short, how would I go about hooking into the kernel directly to
try and find these problems? Is there a way to watch just about
everything going on when these events happen?

Thanks for the help,
Tyler
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