[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <6030f4b8-6576-6ae9-ba8a-9f1e42dfe7d5@amd.com>
Date: Tue, 18 Jun 2024 16:04:48 -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 v4 06/19] x86/resctrl: Introduce interface to display
number of ABMC counters
Hi Reinette,
On 6/13/24 19:57, Reinette Chatre wrote:
> Hi Babu,
>
> On 5/24/24 5:23 AM, Babu Moger wrote:
>> The ABMC feature provides an option to the user to assign a hardware
>> counter to an RMID and monitor the bandwidth as long as the counter
>> is assigned. Number of assignments depend on number of ABMC counters
>> available.
>
> Take care that this interface will not just be used by ABMC. I assumed that
> when the user switches to "soft-RMID" then the value of "num_cntrs" will
> change?
It can be used by both ABMC and "soft-RMID". Will update the information
to be bit generic.
>
>>
>> Provide the interface to display the number of ABMC counters supported.
>>
>> Signed-off-by: Babu Moger <babu.moger@....com>
>> ---
>> v4: Changed the counter name to num_cntrs. And few text changes.
>>
>> v3: Changed the field name to mbm_assign_cntrs.
>>
>> v2: Changed the field name to mbm_assignable_counters from abmc_counters.
>> ---
>> Documentation/arch/x86/resctrl.rst | 4 ++++
>> arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
>> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 ++++++++++++++++
>> 3 files changed, 21 insertions(+)
>>
>> diff --git a/Documentation/arch/x86/resctrl.rst
>> b/Documentation/arch/x86/resctrl.rst
>> index 02790efaabcc..7ab8172ef208 100644
>> --- a/Documentation/arch/x86/resctrl.rst
>> +++ b/Documentation/arch/x86/resctrl.rst
>> @@ -257,6 +257,10 @@ with the following files:
>> # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
>> 0=0x30;1=0x30;3=0x15;4=0x15
>> +"num_cntrs":
>> + Available when ABMC feature is supported. The number of ABMC counters
>> + available for configuration.
>
> This can only be understood by folks already familiar with AMD's ABMC
> feature. There is
> no information about what "ABMC feature" is, what an "ABMC counter" is and
> what
> "configuration" can be done with it.
I can move this patch after 8/19. I will add details on ABMC feature in
Patch 8/19. Also, keep the details bit generic.
>
> Do you think this num_cntrs will only be used by ABMC? What will happen
> when user
> enables "soft-RMID" or some other mode?
This can be used by both the features. But we don't know how soft-RMID
will be implemented. But, I can make this explanation bit more generic.
>
> Reinette
>
--
Thanks
Babu Moger
Powered by blists - more mailing lists