linux-kernel - Re: [PATCH v16 00/34] x86,fs/resctrl: Support AMD Assignable Bandwidth Monitoring Counters (ABMC)

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Message-ID: <85069db7-63bb-40a2-bd03-0fe7e2e82d4f@amd.com>
Date: Thu, 31 Jul 2025 09:17:36 -0500
From: "Moger, Babu" <bmoger@....com>
To: Reinette Chatre <reinette.chatre@...el.com>,
 Babu Moger <babu.moger@....com>, corbet@....net, tony.luck@...el.com,
 james.morse@....com, tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com
Cc: Dave.Martin@....com, x86@...nel.org, hpa@...or.com,
 akpm@...ux-foundation.org, paulmck@...nel.org, rostedt@...dmis.org,
 Neeraj.Upadhyay@....com, david@...hat.com, arnd@...db.de, fvdl@...gle.com,
 seanjc@...gle.com, jpoimboe@...nel.org, pawan.kumar.gupta@...ux.intel.com,
 xin@...or.com, manali.shukla@....com, tao1.su@...ux.intel.com,
 sohil.mehta@...el.com, kai.huang@...el.com, xiaoyao.li@...el.com,
 peterz@...radead.org, xin3.li@...el.com, kan.liang@...ux.intel.com,
 mario.limonciello@....com, thomas.lendacky@....com, perry.yuan@....com,
 gautham.shenoy@....com, chang.seok.bae@...el.com, linux-doc@...r.kernel.org,
 linux-kernel@...r.kernel.org, peternewman@...gle.com, eranian@...gle.com
Subject: Re: [PATCH v16 00/34] x86,fs/resctrl: Support AMD Assignable
 Bandwidth Monitoring Counters (ABMC)

Hi Reinette,

On 7/30/2025 6:57 PM, Reinette Chatre wrote:
> Hi Babu,
> 
> On 7/30/25 4:31 PM, Moger, Babu wrote:
>> Hi Reinette,,
>>
>> On 7/30/2025 2:47 PM, Reinette Chatre wrote:
>>> Hi Babu,
>>>
>>> On 7/25/25 11:29 AM, Babu Moger wrote:
>>>> i. Change the event configuration for mbm_local_bytes.
>>>>
>>>>      # echo "local_reads, local_non_temporal_writes, local_reads_slow_memory, remote_reads" >
>>>>      /sys/fs/resctrl/info/L3_MON/counter_configs/mbm_local_bytes/event_filter
>>>>
>>>>      # cat /sys/fs/resctrl/info/L3_MON/counter_configs/mbm_local_bytes/event_filter
>>>>      local_reads,local_non_temporal_writes,local_reads_slow_memory,remote_reads
>>>
>>> Above are some more "counter_configs" stragglers.
>>
>> Yea. Sure. Missed that.
>>
>>>
>>> Also, while considering our exchange in [1], I encountered quite a few functions doing
>>> counter management work for which I believe monitor.c would be more appropriate. Centralizing
>>> MBM counter management code to monitor.c was something that you planned for this version
>>> so I may be missing why you decided to keep some of these functions in rdtgroup.c? I
>>> highlighted these functions as I noticed them.
>>>
>>
>> I looked at them. Most of the functions you mentioned are directly referenced in res_common_files[] (show or write) and some of them are even named as rdtgroup_<>. So, was not sure about moving them.
> 
> If you prefer a precedent you can compare with rdtgroup_schemata_write()/rdtgroup_schemata_show()
> that is directly referenced in res_common_files[] while the implementation can be found in
> ctrlmondata.c that is intended to contain the "Cache allocation code".
> 
> I assumed we agreed on this since I specifically highlighted the topic of the handlers in [1] and you
> responded to referring to the handler event_filter_show() and mentioned that you plan to consider the
> others. This version thus looks different from what I thought we agreed on :/

Looks like I misunderstood few things here.  Will take care of it in 
next revision.

Thanks
Babu

> 
>> Sure, I will move them one by one to monitor.c
> 
> [1] https://lore.kernel.org/lkml/0fa9a12b-e900-4ceb-b59c-e653ec3db0ca@intel.com/
>