Re: 2.6.21-mm2 - 100% CPU on ksoftirqd/1

[Valdis.Kletnieks@vt.edu]

On Wed, 09 May 2007 12:08:43 EDT, Valdis.Kletnieks@vt.edu said:

> On Wed, 09 May 2007 01:23:22 PDT, Andrew Morton said:
> > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21/2.6.21-mm2/
> 
> Boots up to multiuser mostly OK.  However...
> 
> It comes up with a screaming ksoftirqd - usually /1 but one boot had /0.
> Just sitting there, 100% CPU according to 'top'.  Tried 'echo t > /proc/sysrq-trigger' to get
> a trace, but it was always running on the other CPU - even after I reniced
> it down to 19 and launched 2 'for(;;)' C programs to suck the cycles.  It would
> be failing to get any CPU - until I did the 'echo t' and then it would be
> "running" again.  Anybody got any good debugging ideas here?

OK, finally tracked this one down - the out-of-tree iwlwifi git tree for the
Intel 3945ABG card had some disagreements with the 2.6.21-mm2 git-wireless.patch

Unfortunately, the last known-working for this was -r5-mm2, as I didn't test
-rc6-mm* or -rc7-mm* for this (I hit other issues with those so I didn't
notice this one).  I'll try to work up some of those tomorrow and see if
I can narrow it down at least a *little* bit.

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