Re: Wild CPU usage times on NetBSD 5

[David Holland <dholland-tech%netbsd.org@localhost>]

On Wed, Nov 25, 2009 at 10:12:54AM -0800, Brian Buhrow wrote:
 >      Hello.  In reading this message, it looks to me like you're getting
 > stuck in the tstile bug, or, at least, something similar.  

He can't be seeing "the tstile bug", because "the tstile bug" is any
generic deadlock, and he's not seeing a deadlock.

What it reminds me of is the bizarre degenerate performance problem
WAPBL had a year or so ago, except that it was fixed and he's not
using WAPBL anyway.

My guess is that it's some kind of adverse dynamic behavior in the
syncer or some similar entity. Tracking such things down is *so* much
fun...

(But I'd expect it to be burning cpu in the kernel, not in userspace.
Maybe it's getting into some kind of signal loop? Any chance of
catching it under ktrace?)

-- 
David A. Holland
dholland%netbsd.org@localhost