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

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Message-ID: <791e12c1-ddb4-4d65-877c-a7d887d3ef6c@amd.com>
Date: Thu, 26 Sep 2024 11:28:52 -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 9/19/24 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.

> 
>>  +{
>> +	int index = MBM_EVENT_ARRAY_INDEX(evtid);
>> +	int cntr_id = rdtgrp->mon.cntr_id[index];
>> +
>> +	/*
>> +	 * Allocate a new counter id to the group if the counter id is not
>> +	 * is not assigned already.
> 
> "is not is not" -> "is not"
> 

Sure.

-- 
Thanks
Babu Moger