On 1/29/19 3:37 AM, Michael Ellerman wrote:

Michael Bringmann [off-list ref] writes:

quoted

On 10/29/18 1:43 PM, Nathan Fontenot wrote:

quoted

On pseries systems, performing a partition migration can result in
altering the nodes a CPU is assigned to on the destination system. For
exampl, pre-migration on the source system CPUs are in node 1 and 3,
post-migration on the destination system CPUs are in nodes 2 and 3.

Handling the node change for a CPU can cause corruption in the slab
cache if we hit a timing where a CPUs node is changed while cache_reap()
is invoked. The corruption occurs because the slab cache code appears
to rely on the CPU and slab cache pages being on the same node.

The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c
does not prevent us from hitting this scenario.

Changing the device tree property update notification handler that
recognizes an affinity change for a CPU to do a full DLPAR remove and
add of the CPU instead of dynamically changing its node resolves this
issue.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com

Signed-off-by: Michael W. Bringmann <redacted>

Tested-by: Michael W. Bringmann <redacted>

Are you sure that's what you meant? ie. you wrote some of the patch?

What I'd like is to get a Tested-by from you.

cheers

-- 
Michael W. Bringmann
Linux Technology Center
IBM Corporation
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External: (512) 286-5196
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mwb@linux.vnet.ibm.com