Re: [PATCH V6 0/2] powerpc/dlpar: Correct display of hot-add/hot-remove CPUs and memory

From: Michael Bringmann
Date: Wed Jun 21 2017 - 10:19:03 EST

One of the patches was doubled and sent twice yesterday.
Will update number regardless in future.

On 06/21/2017 04:54 AM, Michael Ellerman wrote:
> Michael Bringmann <mwb@xxxxxxxxxxxxxxxxxx> writes:
>> On Power systems with shared configurations of CPUs and memory, there
>> are some issues with association of additional CPUs and memory to nodes
>> when hot-adding resources. These patches address some of those problems.
>> powerpc/hotplug: On systems like PowerPC which allow 'hot-add' of CPU
>> or memory resources, it may occur that the new resources are to be
>> inserted into nodes that were not used for these resources at bootup.
>> In the kernel, any node that is used must be defined and initialized
>> at boot. In order to meet both needs, this patch adds a new kernel
>> command line option (numnodes=<int>) for use by the PowerPC
>> architecture-specific code that defines the maximum number of nodes
>> that the kernel will ever need in its current hardware environment.
>> The boot code that initializes nodes for PowerPC will read this value
>> and use it to ensure that all of the desired nodes are setup in the
>> 'node_possible_map', and elsewhere.
>> powerpc/numa: Correct the currently broken capability to set the
>> topology for shared CPUs in LPARs. At boot time for shared CPU
>> lpars, the topology for each shared CPU is set to node zero, however,
>> this is now updated correctly using the Virtual Processor Home Node
>> (VPHN) capabilities information provided by the pHyp. The VPHN handling
>> in Linux is disabled, if PRRN handling is present.
>> Signed-off-by: Michael Bringmann <mwb@xxxxxxxxxxxxxxxxxx>
>> Michael Bringmann (2):
>> powerpc/hotplug: Add option to define max nodes allowing dynamic
>> growth of resources.
>> powerpc/numa: Update CPU topology when VPHN enabled
>> ---
>> Changes in V6:
>> -- Reorder some code to better eliminate unused functions in
>> conditional builds.
> What changed between yesterday's V6 and this V6?
> If you're going to resend, please bump the version number, we have tools
> that parse the subject and version, and resending multiple times with
> the same number breaks those.
> cheers

Michael W. Bringmann
Linux Technology Center
IBM Corporation
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External: (512) 286-5196
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