Intermittent system hangs on 7.2-RELEASE-p1
linda.messerschmidt at gmail.com
Thu Aug 27 20:14:40 UTC 2009
On Wed, Aug 26, 2009 at 4:42 PM, John Baldwin<jhb at freebsd.org> wrote:
> One thing to note is that ktrace only logs voluntary context switches (i.e.
> call to tsleep or waiting on a condition variable). It specifically does not
> log preemptions or blocking on a mutex,
I was not aware, thanks.
> so in theory if your machine was
> livelocked temporarily that might explain this.
How would we determine that?
We are now able to reproduce this on a test machine, even after
slipping in a 7.2-STABLE kernel with KTR enabled. So we have a lot
more options now.
Unfortunately, I don't really "get" KTR yet. It looks like it has
relevant info, but I was unable to correlate its huge timestamps (e.g.
6795522404430562) to ktrace output times (e.g. 1251387606.225544)
showing problem areas.
What's my best bet from here?
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