linux-kernel - Re: [PATCH v5 15/20] x86/resctrl: Assign/unassign counters by default when ABMC is enabled

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Message-ID: <c651e5f6-cf58-b75f-db21-61784007a201@amd.com>
Date: Fri, 26 Jul 2024 18:57:11 -0500
From: "Moger, Babu" <bmoger@....com>
To: Peter Newman <peternewman@...gle.com>, Babu Moger <babu.moger@....com>
Cc: corbet@....net, fenghua.yu@...el.com, reinette.chatre@...el.com,
 tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com,
 paulmck@...nel.org, rdunlap@...radead.org, tj@...nel.org,
 peterz@...radead.org, yanjiewtw@...il.com, kim.phillips@....com,
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 daniel.sneddon@...ux.intel.com, pbonzini@...hat.com, sandipan.das@....com,
 ilpo.jarvinen@...ux.intel.com, maciej.wieczor-retman@...el.com,
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 james.morse@....com
Subject: Re: [PATCH v5 15/20] x86/resctrl: Assign/unassign counters by default
 when ABMC is enabled

Hi Peter,

On 7/26/2024 6:22 PM, Peter Newman wrote:
> Hi Babu,
> 
> On Wed, Jul 3, 2024 at 2:50 PM Babu Moger <babu.moger@....com> wrote:
> 
>> @@ -3894,6 +3956,17 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
>>          if (ret)
>>                  goto out_closid_free;
>>
>> +       /*
>> +        * Assign the counters if ABMC is already enabled.
>> +        * With the limited number of counters, there can be cases
>> +        * only on assignment succeed. It is not required to fail
>> +        * here in that case. Users have the option to assign the
>> +        * counter later.
>> +        */
>> +
>> +       if (rdtgroup_assign_cntrs(rdtgrp) < 0)
>> +               rdt_last_cmd_puts("Monitor assignment failed\n");
> 
> Supposing rdtgroup_init_alloc() below fails, would you want to release
> the counters allocated here?

Yes. Sure. Fix it in v6.
> 
>> +
>>          kernfs_activate(rdtgrp->kn);
>>
>>          ret = rdtgroup_init_alloc(rdtgrp);
> 
> -Peter
> 

-- 
- Babu Moger