Subject: Re: [PATCH] Correct cpu affinity for dlpar added cpus

From: Nathan Fontenot <[email-masked]>
Date: Wed, 29 Apr 2015 10:33:50 -0500

On 04/28/2015 11:53 PM, Michael Ellerman wrote:
> Subject should be "powerpc/pseries: ..." please.

ok

> 
> On Tue, 2015-04-28 at 10:37 -0500, Nathan Fontenot wrote:
>> The incorrect ordering of operations during cpu dlpar causes the affinity
>> of cpus being added to be invalid. Phyp does not assign affinity information
>> for a cpu until the rtas set-indicator calls are made to set the isolation
>> and allocation state. In the current code we call rtas configure-connector
>> before making the set-indicator calls which results in invalid data in the
>> ibm,associativity property for the cpu we're adding.
> 
> Invalid and benign? Or invalid and causes an oops or ..?
>

Invalid and benign. I'll add this to the description.
 
>> This patch corrects the order of operations to make the set-indicator
>> calls (done in acquire_drc) before calling configure-connector.
> 
> Which commit added the code and/or caused it to be wrong?
> 
>   https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/SubmittingPatches#n187
> 

And the commit that this fixes..

> 
> While looking at the code I notice it looks like we leak a reference if
> dlpar_configure_connector() fails:
> 
> 	parent = of_find_node_by_path("/cpus");
> 	if (!parent)
> 		return -ENODEV;
> 
> 	dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
> 	if (!dn)
> 		return -EINVAL;
> 
> 	of_node_put(parent);
> 
> 
> Please send a separate patch to fix that.

Yep, saw that too.

New patches on their way.

Thanks for the feedback,
-Nathan