Re: [PATCH v2] powerpc: VPHN topology change updates all siblings

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jul 24, 2013 at 10:00:05AM -0500, Robert Jennings wrote:
> When an associativity level change is found for one thread, the
> siblings threads need to be updated as well.  This is done today
> for PRRN in stage_topology_update() but is missing for VPHN in
> update_cpu_associativity_changes_mask().
> 
> All threads should be updated to move to the new node.  Without this
> patch, a single thread may be flagged for a topology change, leaving it
> in a different node from its siblings, which is incorrect.  This causes
> problems for the scheduler where overlapping scheduler groups are created
> and a loop is formed in those groups.
> 
> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
> ---
> cpu_sibling_mask is now defined for UP which fixes that build break.
> ---
>  arch/powerpc/include/asm/smp.h |  4 +++
>  arch/powerpc/mm/numa.c         | 59 +++++++++++++++++++++++++++++++-----------
>  2 files changed, 48 insertions(+), 15 deletions(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

</formletter>