Re: [PATCH v5 21/40] x86/resctrl: Change mon_event_config_{read,write}() to be arch helpers

[James Morse]

Hi Reinette,

On 23/10/2024 23:19, Reinette Chatre wrote:
> On 10/4/24 11:03 AM, James Morse wrote:
>> @@ -315,6 +322,24 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
>>  
>>  bool __init resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);
>>  
>> +/**
>> + * resctrl_arch_mon_event_config_write() - Write the config for a counter.
> 
> Please avoid the term "counter" for events ... the upcoming AMD work adds support
> for counters*. 

Fixed.


>> + * @info:	struct resctrl_mon_config_info describing the resource, domain
>> + *		and event.
> 
> Expected "config" to appear as part of information about function
> that claims to writes config?

I'll rename the variable.


>> + *
>> + * Must be called on a CPU that is a member of the specified domain.

> I am not sure about this. Is this documentation intended to support authors of
> arch code? In that case it may be instead useful to know that this function will be
> called on a CPU that is a member of the specified domain to avoid confusion from arch
> side whether it needs to take some action to ensure function is called on right CPU.
> 
> 	Called on a CPU that is a member of the specified domain.

I don't think we have clear idea who this documentation is for - I'm assuming its for the
caller...

I'll change this to "Called via IPI to reach a CPU that is a member of the specified
domain", as that covers both views, and adds that its called in irq context.


>> + */
>> +void resctrl_arch_mon_event_config_write(void *info);
>> +
>> +/**
>> + * resctrl_arch_mon_event_config_read() - Read the config for a counter.
> 
> counter -> event
> 
>> + * @info:	struct resctrl_mon_config_info describing the resource, domain
>> + *		and event.
> 
> Copy&paste? No information on how config is returned.

Laziness - there is only one possible place it could be! I've added:
| * Reads resource, domain and eventid from @config_info and reads the
|  * hardware config value into config_info->mon_config.

and similar on the other function.


Thanks,

James