linux-kernel - Re: [PATCH v13 00/27] x86/resctrl : Support AMD Assignable Bandwidth Monitoring Counters (ABMC)

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <9b08ab86-22d2-40c1-be20-fcc73ee98b3d@amd.com>
Date: Tue, 10 Jun 2025 18:19:25 -0500
From: "Moger, Babu" <bmoger@....com>
To: Reinette Chatre <reinette.chatre@...el.com>, babu.moger@....com,
 Peter Newman <peternewman@...gle.com>
Cc: corbet@....net, tony.luck@...el.com, tglx@...utronix.de,
 mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
 james.morse@....com, dave.martin@....com, fenghuay@...dia.com,
 x86@...nel.org, hpa@...or.com, paulmck@...nel.org,
 akpm@...ux-foundation.org, thuth@...hat.com, rostedt@...dmis.org,
 ardb@...nel.org, gregkh@...uxfoundation.org, daniel.sneddon@...ux.intel.com,
 jpoimboe@...nel.org, alexandre.chartre@...cle.com,
 pawan.kumar.gupta@...ux.intel.com, thomas.lendacky@....com,
 perry.yuan@....com, seanjc@...gle.com, kai.huang@...el.com,
 xiaoyao.li@...el.com, kan.liang@...ux.intel.com, xin3.li@...el.com,
 ebiggers@...gle.com, xin@...or.com, sohil.mehta@...el.com,
 andrew.cooper3@...rix.com, mario.limonciello@....com,
 linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
 maciej.wieczor-retman@...el.com, eranian@...gle.com, Xiaojian.Du@....com,
 gautham.shenoy@....com
Subject: Re: [PATCH v13 00/27] x86/resctrl : Support AMD Assignable Bandwidth
 Monitoring Counters (ABMC)

Hi Reinette,

On 5/22/2025 11:33 AM, Reinette Chatre wrote:
> Hi Babu,
> 
> On 5/22/25 8:44 AM, Moger, Babu wrote:
>> On 5/21/25 18:03, Reinette Chatre wrote:
> 
> ...
> 
>>> This is why I proposed in [3] that the name of the mode reflects how user can interact
>>> with the system. Instead of one "mbm_cntr_assign" mode there can be "mbm_cntr_event_assign"
>>> that is used for ABMC and "mbm_cntr_group_assign" that is used for soft-ABMC. The mode should
>>> make it clear what the system is capable of wrt counter assignments.
>>
>> Yes, that makes sense. Perhaps we can also simplify it further:
>>
>> # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode:
>> [mbm_cntr_evt_assign] <- for ABMC
>>   mbm_cntr_grp_assign  <- for soft-ABMC
> 
> Looks good to me. Thank you.

I am actually ready with v14 series. I have good feeling that we are 
getting closer to making these changes final.

So, Looking back again, it might make more sense to rename few user 
visible interfaces.

1. # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode.
    [mbm_assign_event] <- for ABMC
     mbm_assign_group  <- for soft-ABMC

    This looks much more cleaner.  It matches with "mbm_assign_mode"

Similarly, we can rename few functions and variable names to make little 
more readable.

2. mbm_cntr_assignable -> mbm_assignable

3. resctrl_arch_mbm_cntr_assign_enabled
  -> >resctrl_arch_mbm_assign_enabled

4. mbm_cntr_assign_enabled -> mbm_assign_enabled

5. resctrl_arch_mbm_cntr_assign_set_one ->

    resctrl_arch_mbm_assign_set_one.

6. There will few more functions. I will look into that if you agree 
with approach.

7. No need to change few of these below. These are related to actual 
counters.
    num_mbm_cntrs
    available_mbm_cntrs

What do you think?

Thanks
Babu Moger