linux-kernel - Re: [PATCH v7 09/24] x86/resctrl: Introduce bitmap mbm_cntr_free

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <e1e8dd73-7624-4b5b-a922-8b031b9c42fd@amd.com>
Date: Tue, 24 Sep 2024 12:01:14 -0500
From: "Moger, Babu" <babu.moger@....com>
To: Peter Newman <peternewman@...gle.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,
 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, 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 09/24] x86/resctrl: Introduce bitmap mbm_cntr_free_map
 to track assignable counters

Hi Peter,

On 9/24/24 11:25, Peter Newman wrote:
> Hi Babu,
> 
> On Wed, Sep 4, 2024 at 3:23 PM Babu Moger <babu.moger@....com> wrote:
> 
>> diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
>> index f11d6fdfd977..aab22ff8e0c1 100644
>> --- a/include/linux/resctrl.h
>> +++ b/include/linux/resctrl.h
>> @@ -187,12 +187,14 @@ enum resctrl_scope {
>>   * @num_rmid:          Number of RMIDs available
>>   * @num_mbm_cntrs:     Number of assignable monitoring counters
>>   * @mbm_cntr_assignable:Is system capable of supporting monitor assignment?
>> + * @mbm_cntr_free_map: bitmap of number of assignable MBM counters
>>   * @evt_list:          List of monitoring events
>>   */
>>  struct resctrl_mon {
>>         int                     num_rmid;
>>         int                     num_mbm_cntrs;
>>         bool                    mbm_cntr_assignable;
>> +       unsigned long           *mbm_cntr_free_map;
>>         struct list_head        evt_list;
>>  };
> 
> This looks global still. Will only all-domain (*=) operations be
> supported initially?

Yes. It is supported in this series.

We have one counter at global level and another at domain level.
https://lore.kernel.org/lkml/7a24bb182897acab3daaac1cadaabca3bcc73dc5.1725488488.git.babu.moger@amd.com/

Domain level counter is used for tracking the counters status in each domain.

Global counter is released once the counter is freed in all the domains.

-- 
Thanks
Babu Moger