linux-kernel - Re: [PATCH v9 17/26] x86/resctrl: Implement resctrl_arch_config

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Message-ID: <9b510a12-b0de-4143-806b-493c29f4ff00@intel.com>
Date: Fri, 22 Nov 2024 13:52:23 -0800
From: Reinette Chatre <reinette.chatre@...el.com>
To: <babu.moger@....com>, <corbet@....net>, <tglx@...utronix.de>,
	<mingo@...hat.com>, <bp@...en8.de>, <dave.hansen@...ux.intel.com>
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Subject: Re: [PATCH v9 17/26] x86/resctrl: Implement
 resctrl_arch_config_cntr() to assign a counter with ABMC

Hi Babu,

On 11/22/24 10:54 AM, Moger, Babu wrote:
> Hi Reinette,
> 
> On 11/21/2024 2:18 PM, Reinette Chatre wrote:
>> Hi Babu,
>>
>> On 11/19/24 12:12 PM, Moger, Babu wrote:
>>> Hi Reinette,
>>>
>>> On 11/15/24 18:44, Reinette Chatre wrote:
>>>> Hi Babu,
>>>>
>>>> On 10/29/24 4:21 PM, Babu Moger wrote:
>>>>> The ABMC feature provides an option to the user to assign a hardware
>>>>> counter to an RMID, event pair and monitor the bandwidth as long as it is
>>>>> assigned. The assigned RMID will be tracked by the hardware until the user
>>>>> unassigns it manually.
>>>>>
>>>>> Counters are configured by writing to L3_QOS_ABMC_CFG MSR and
>>>>> specifying the counter id, bandwidth source, and bandwidth types.
>>>>
>>>> needs imperative tone
>>>
>>> How about this?
>>>
>>> Configure the counters by writing to the L3_QOS_ABMC_CFG MSR and
>>> specifying the counter ID, bandwidth source, and bandwidth types.
>>>
>>
>> ok with me. Exactly what ChatGPT suggests.
> 
> Hmm. ):
> 
>>
>> Please do note that that first paragraph informs reader that
>> a counter is assigned by user to "an RMID, event pair" while the hardware is configured with
>> "the counter ID, bandwidth source, and bandwidth types". There thus does not seem
>> to be a clear connection between what user assigns and what is programmed to hardware.
>>
> 
> Adding RMID in the text might help.
> 
> Configure the counters by writing to the L3_QOS_ABMC_CFG MSR and specifying the counter ID, RMID, bandwidth source, and bandwidth types.
> 

Isn't the bandwidth source and the RMID the same thing? How about something like:
"Configure the counters by writing to the L3_QOS_ABMC_CFG MSR and specifying
 the counter ID, bandwidth source (RMID), and bandwidth event configuration."

Please feel free to improve.

Reinette