Re: [PATCH] pseries/lparcfg: Add resource group monitoring

[Shrikanth Hegde <sshegde@linux.ibm.com>]

On 8/5/25 11:13, Srikar Dronamraju wrote:
> * Shrikanth Hegde <sshegde@linux.ibm.com> [2025-08-01 19:27:22]:
> 

>>
>> Could you please add a link to patch on power utils on how it is being consumed?
> 
> I am not sure I understood your query, it looks a bit ambiguous.
> 
> If your query is on how lparcfg data is being consumed.
> All tools that are consuming lparcfg will continue to use the same way.
> Since this is not changing the way lparcfg is being consumed, I think it is
> redundant information that need not be carried in all the changes/commits to
> lparcfg. Such an information would be required when lparcfg file was
> created.

I was saying you could point to power utils patch that you have sent which says how
one would consume this.

https://groups.google.com/g/powerpc-utils-devel/c/8b2Ixk8vk2w

> 
> If your query is on how resource group data is being consumed by users.

>>
>> Does MODULE_VERS need to increased?
> 
> All tools that are consuming lparcfg will continue to use the same way.
> If there was some conditional changes that need to be done by the tools,
> then we should have updated the same.
> Hence there is not need to update MODULE_VERS.
> 

Since there are two new fields user scripts might need change is why i was suggesting
we might need to increase MODULE_VERS

>>
>>> @@ -78,6 +78,8 @@ struct hvcall_ppp_data {
>>>    	u8	capped;
>>>    	u8	weight;
>>>    	u8	unallocated_weight;
>>> +	u8      resource_group_index;
>>> +	u16     active_procs_in_resource_group;
>>>    	u16	active_procs_in_pool;
>>>    	u16	active_system_procs;
>>>    	u16	phys_platform_procs;
>>> @@ -86,7 +88,7 @@ struct hvcall_ppp_data {
>>>    };
>>>    /*
>>> - * H_GET_PPP hcall returns info in 4 parms.
>>> + * H_GET_PPP hcall returns info in 5 parms.
>>>     *  entitled_capacity,unallocated_capacity,
>>>     *  aggregation, resource_capability).
>>>     *
>>> @@ -94,11 +96,11 @@ struct hvcall_ppp_data {
>>>     *  R5 = Unallocated Processor Capacity Percentage.
>>>     *  R6 (AABBCCDDEEFFGGHH).
>>>     *      XXXX - reserved (0)
>>> - *          XXXX - reserved (0)
>>> + *          XXXX - Active Cores in Resource Group
>>>     *              XXXX - Group Number
>>>     *                  XXXX - Pool Number.
>>>     *  R7 (IIJJKKLLMMNNOOPP).
>>> - *      XX - reserved. (0)
>>> + *      XX - Resource group Number
>>>     *        XX - bit 0-6 reserved (0).   bit 7 is Capped indicator.
>>>     *          XX - variable processor Capacity Weight
>>>     *            XX - Unallocated Variable Processor Capacity Weight.
>>> @@ -120,9 +122,11 @@ static unsigned int h_get_ppp(struct hvcall_ppp_data *ppp_data)
>>>    	ppp_data->entitlement = retbuf[0];
>>>    	ppp_data->unallocated_entitlement = retbuf[1];
>>> +	ppp_data->active_procs_in_resource_group = (retbuf[2] >> 4 * 8) & 0xffff;
>>>    	ppp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
>>>    	ppp_data->pool_num = retbuf[2] & 0xffff;
>>> +	ppp_data->resource_group_index = (retbuf[3] >> 7 *  8) & 0xff;
>>>    	ppp_data->capped = (retbuf[3] >> 6 * 8) & 0x01;
>>>    	ppp_data->weight = (retbuf[3] >> 5 * 8) & 0xff;
>>>    	ppp_data->unallocated_weight = (retbuf[3] >> 4 * 8) & 0xff;
>>> @@ -236,6 +240,13 @@ static void parse_ppp_data(struct seq_file *m)
>>>    	seq_printf(m, "unallocated_capacity=%lld\n",
>>>    		   ppp_data.unallocated_entitlement);
>>> +	if (ppp_data.active_procs_in_resource_group)  {
>>
>> ppp_data.active_procs_in_resource_group can ever be zero?
>>
>> If the entry is absent in lparcfg, then lparstat will print it as 0 (which happens to be
>> default RG, while default RG may have processors)
> 
> If active_procs_in_resource_group is 0, then we are not printing the
> resource group information. If active_procs_in_resource_group is non-zero
> and resource_group_index is wrong, we need to report a bug to the firmware
> to update it. Kernel is very transparent with respect to this information.
> It can neither verify the information received nor should we even be doing
> this.
> 
>>
The comment was more on the necessity of if statement there.

+	if (ppp_data.active_procs_in_resource_group)  {

If one runs lparstat in the LPAR, that means ppp_data.active_procs_in_resource_group is non zero. and when
ppp_data.active_procs_in_resource_group is zero, i don't think one can run lparstat in any of such LPAR.

btw, ppp_data.active_procs_in_resource_group can be fraction between 0,1 or is it always an integer number?