Re: Regression in 2.6.23-rc2-mm2, mounting cpusets causes a hang

[Lee Schermerhorn <Lee.Schermerhorn@hp.com>]

On Tue, 2007-08-14 at 13:03 -0500, Serge E. Hallyn wrote:
> Quoting Lee Schermerhorn (Lee.Schermerhorn@hp.com):
> > On Mon, 2007-08-13 at 15:12 -0500, Serge E. Hallyn wrote:
> > > Quoting Dhaval Giani (dhaval@linux.vnet.ibm.com):
> > > > Hi,
> > > > 
> > > > On mounting cpusets using containers, I have been hitting the following
> > > > bug.
> > > > 
> > > > 
> > > > -----------[ cut here ]------------
> > > > kernel BUG at kernel/cpuset.c:331!
> > <snip>
> > > > CONFIG_HIGHMEM=y
> > > > CONFIG_X86_PAE=y
> > > > # CONFIG_NUMA is not set
> > > > CONFIG_ARCH_POPULATES_NODE_MAP=y
> > > > CONFIG_SELECT_MEMORY_MODEL=y
> > > > CONFIG_FLATMEM_MANUAL=y
> > > > # CONFIG_DISCONTIGMEM_MANUAL is not set
> > > > # CONFIG_SPARSEMEM_MANUAL is not set
> > > > CONFIG_FLATMEM=y
> > > > CONFIG_FLAT_NODE_MEM_MAP=y
> > > > # CONFIG_SPARSEMEM_STATIC is not set
> > > > CONFIG_SPLIT_PTLOCK_CPUS=4
> > > > CONFIG_RESOURCES_64BIT=y
> > > > CONFIG_ZONE_DMA_FLAG=1
> > <snip>
> > > 
> > > Yeah, I'm seeing the same thing.  Oddly, my node_states[N_NORMAL_MEMORY]
> > > and node_states[N_HIGH_MEMORY] are empty, while node_states[N_ONLINE]
> > > contains my single cpu (on i386 kvm image).
> > > 
> > > -serge
> > 
> > Yes, you'll definitely hit that BUG if the N_HIGH_MEMORY mask is empty.
> > So far, I can't see how this could be, tho'.  __build_all_zonelists()
> > should be called for non-NUMA as well as NUMA.  It iterates over "all
> 
> Yup, and it is, and some debug statements insist that
> node_set_state(nid, N_HIGH_MEMORY) is being called for cpu 0,
> and the state is in fact being correctly set.
> 
> So it must get cleared later...

OK.  That helps.  I'll see what I can find...

Thanks,
Lee