linux-kernel - Re: [PATCH v7 16/24] x86/resctrl: Add the interface to assign/update counter assignment

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Message-ID: <9573dd90-a028-493f-9957-83ef787badda@amd.com>
Date: Thu, 26 Sep 2024 11:59:32 -0500
From: "Moger, Babu" <babu.moger@....com>
To: Reinette Chatre <reinette.chatre@...el.com>, corbet@....net,
 fenghua.yu@...el.com, tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com
Cc: x86@...nel.org, hpa@...or.com, paulmck@...nel.org, rdunlap@...radead.org,
 tj@...nel.org, peterz@...radead.org, yanjiewtw@...il.com,
 kim.phillips@....com, lukas.bulwahn@...il.com, seanjc@...gle.com,
 jmattson@...gle.com, leitao@...ian.org, jpoimboe@...nel.org,
 rick.p.edgecombe@...el.com, kirill.shutemov@...ux.intel.com,
 jithu.joseph@...el.com, kai.huang@...el.com, kan.liang@...ux.intel.com,
 daniel.sneddon@...ux.intel.com, pbonzini@...hat.com, sandipan.das@....com,
 ilpo.jarvinen@...ux.intel.com, peternewman@...gle.com,
 maciej.wieczor-retman@...el.com, linux-doc@...r.kernel.org,
 linux-kernel@...r.kernel.org, eranian@...gle.com, james.morse@....com
Subject: Re: [PATCH v7 16/24] x86/resctrl: Add the interface to assign/update
 counter assignment

Hi Reinette,

On 9/26/24 11:46, Reinette Chatre wrote:
> Hi Babu,
> 
> On 9/26/24 9:28 AM, Moger, Babu wrote:
>> Hi Reinette,
>>
>>
>> On 9/19/24 12:20, Reinette Chatre wrote:
>>> Hi Babu,
>>>
>>> On 9/4/24 3:21 PM, Babu Moger wrote:
>>>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>>>> index 7ad653b4e768..1d45120ff2b5 100644
>>>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>>>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>>>> @@ -864,6 +864,13 @@ static int rdtgroup_rmid_show(struct kernfs_open_file *of,
>>>>  	return ret;
>>>>  }
>>>>  
>>>> +/*
>>>> + * Get the counter index for the assignable counter
>>>> + * 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID
>>>> + * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
>>>> + */
>>>> +#define MBM_EVENT_ARRAY_INDEX(_event) ((_event) - 2)
>>>> +
>>>>  static int rdtgroup_mbm_assign_mode_show(struct kernfs_open_file *of,
>>>>  					 struct seq_file *s, void *v)
>>>>  {
>>>> @@ -1898,6 +1905,45 @@ int resctrl_arch_assign_cntr(struct rdt_resource *r, struct rdt_mon_domain *d,
>>>>  	return 0;
>>>>  }
>>>>  
>>>> +/*
>>>> + * Assign a hardware counter to the group.
>>>> + * Counter will be assigned to all the domains if rdt_mon_domain is NULL
>>>> + * else the counter will be allocated to specific domain.
>>>> + */
>>>> +int rdtgroup_assign_cntr(struct rdt_resource *r, struct rdtgroup *rdtgrp,
>>>> +			 struct rdt_mon_domain *d, enum resctrl_event_id evtid)
>>>
>>> Could we please review the naming of function as this series progresses? Using such a generic
>>> name for this specific function seems to result in its callers later in series having even more
>>> generic names that are hard to decipher. For example, later (very generic) "rdtgroup_assign_grp()"
>>> calls this function and I find rdtgroup_assign_grp() to be very vague making the code more difficult
>>> to follow. For example, rdtgroup_assign_cntr() could be rdtgroup_assign_cntr_event() and
>>> rdtgroup_assign_grp() could instead be rdtgroup_assign_cntr()?  Please feel free to improve.
>>
>> Sure.
>>
>> How about rdtgroup_assign_cntr_event() and rdtgroup_assign_cntr_grp() ?
>>
>> Added grp extension for the second one.
> 
> Is the "grp" extension needed? The function already has "rdtgroup_" as prefix so
> the "grp" extension does not seem necessary to me since I think "rdtgroup_" and "grp"
> intend to refer to the same?

How about rdtgroup_assign_cntrs() ?  Added 's' in the end.

We are assigning multiple counters here.

-- 
Thanks
Babu Moger