On 03/27/2010 08:43 AM, Kent Overstreet wrote:commit 5beb49305251e5669852ed541e8e2f2f7696c53e
Author: Rik van Riel <riel@xxxxxxxxxx>
Date: Fri Mar 5 13:42:07 2010 -0800
mm: change anon_vma linking to fix multi-process server scalability issue
I get this when starting kvm. The warning hasn't caused me problems, but
I've also been getting a scheduling while atomic panic when I start kvm
that I can only reproduce when I don't want to. It's definitely config
dependent, I'd guess preempt might have something to do with it.
From your trace, it looks like mm_take_all_locks is taking close
to 256 locks, which is where the preempt_count could overflow into
the softirq count.
Since kvm-qemu is exec'd, I am guessing you have a very large
number of VMAs in your qemu process. Is that correct?
Peter, would it be safe to increase PREEMPT_BITS to eg. 10?