Re: [PATCH v5] pseries: prevent free CPU ids to be reused on another node

From: Michael Ellerman
Date: Wed Aug 18 2021 - 09:46:27 EST


On Thu, 29 Apr 2021 19:49:08 +0200, Laurent Dufour wrote:
> When a CPU is hot added, the CPU ids are taken from the available mask from
> the lower possible set. If that set of values was previously used for CPU
> attached to a different node, this seems to application like if these CPUs
> have migrated from a node to another one which is not expected in real
> life.
>
> To prevent this, it is needed to record the CPU ids used for each node and
> to not reuse them on another node. However, to prevent CPU hot plug to
> fail, in the case the CPU ids is starved on a node, the capability to reuse
> other nodes’ free CPU ids is kept. A warning is displayed in such a case
> to warn the user.
>
> [...]

Applied to powerpc/next.

[1/1] pseries: prevent free CPU ids to be reused on another node
https://git.kernel.org/powerpc/c/bd1dd4c5f5286df0148b5b316f37c583b8f55fa1

cheers