[AMD Official Use Only - General]

Hi Reinette,

> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@intel.com>
> Sent: Thursday, May 4, 2023 1:54 PM
> To: Moger, Babu <Babu.Moger@amd.com>; corbet@lwn.net;
> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de
> Cc: fenghua.yu@intel.com; dave.hansen@linux.intel.com; x86@kernel.org;
> hpa@zytor.com; paulmck@kernel.org; akpm@linux-foundation.org;
> quic_neeraju@quicinc.com; rdunlap@infradead.org;
> damien.lemoal@opensource.wdc.com; songmuchun@bytedance.com;
> peterz@infradead.org; jpoimboe@kernel.org; pbonzini@redhat.com;
> chang.seok.bae@intel.com; pawan.kumar.gupta@linux.intel.com;
> jmattson@google.com; daniel.sneddon@linux.intel.com; Das1, Sandipan
> <Sandipan.Das@amd.com>; tony.luck@intel.com; james.morse@arm.com;
> linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org;
> bagasdotme@gmail.com; eranian@google.com; christophe.leroy@csgroup.eu;
> jarkko@kernel.org; adrian.hunter@intel.com; quic_jiles@quicinc.com;
> peternewman@google.com
> Subject: Re: [PATCH v4 0/7] x86/resctrl: Miscellaneous resctrl features
> 
> Hi Babu,
> 
> On 4/17/2023 4:33 PM, Babu Moger wrote:
> > These series adds support few minor features.
> > 1. Support assigning multiple tasks to control/mon groups in one command.
> > 2. Add debug mount option for resctrl interface.
> > 3. Add RMID and CLOSID in resctrl interface when mounted with debug
> option.
> > 4. While doing these above changes, found that rftype flags needed some
> cleanup.
> >    They were named inconsistently. Re-arranged them much more cleanly
> now.
> >    Hope it can help future additions.
> >
> > ---
> > v4: Changes since v3
> >     Addressed comments from Reinette and others.
> >     Removed newline requirement when adding tasks.
> >     Dropped one of the changes on flags. Kept the flag names mostly same.
> >     Changed the names of closid and rmid to ctrl_hw_id and mon_hw_id
> respectively.
> >     James had some concerns about adding these files. But I thing it is big
> problem.
> >     Please comment back if we can do better.
> 
> From what I understand the primary concern was the naming of the files, which
> you address in this version.
> 
> A second point I saw was a request for insight into why user space may need
> this (James recommended obfuscation when value is only shared between
> kernel interfaces).
> You did answer this in your response and since there was no follow-up I
> currently assume that this has been answered.
> 
> Unless we hear otherwise from James I thus believe that his feedback is
> addressed.

Ok. Sounds good.

> 
> >     Tried to address Reinette's comment on patch 7. But due to current code
> design
> >     I could not do it exact way. But changed it little bit to make it easy debug
> >     file additions in the future.
> 
> Could you please elaborate? It actually looks like you may be headed there next
> according to:
> https://lore.kernel.org/lkml/933d8ae2-d8b7-7436-5918-
> f639405c9ecb@amd.com/

Sorry, I was talking about this comment.
https://lore.kernel.org/lkml/fef12c9e-7d6f-bcd4-f92e-e776eb9e673b@intel.com/

I tried to address it here. 
https://lore.kernel.org/lkml/168177451010.1758847.568218491528297451.stgit@bmoger-ubuntu/

This may not be the exact way you mentioned.  Reason is, adding the flags before rdtgroup_add_files cannot be done. It does not update the resctrl root filesystem.
These files have to added by calling rdtgroup_add_file and kernfs_activate in rdt_enable_ctx.
Thanks
Babu

Hi Babu,

On 5/5/2023 8:43 AM, Moger, Babu wrote:
> [AMD Official Use Only - General]
> 
> Hi Reinette,
> 
>> -----Original Message-----
>> From: Reinette Chatre <reinette.chatre@intel.com>
>> Sent: Thursday, May 4, 2023 1:54 PM
>> To: Moger, Babu <Babu.Moger@amd.com>; corbet@lwn.net;
>> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de
>> Cc: fenghua.yu@intel.com; dave.hansen@linux.intel.com; x86@kernel.org;
>> hpa@zytor.com; paulmck@kernel.org; akpm@linux-foundation.org;
>> quic_neeraju@quicinc.com; rdunlap@infradead.org;
>> damien.lemoal@opensource.wdc.com; songmuchun@bytedance.com;
>> peterz@infradead.org; jpoimboe@kernel.org; pbonzini@redhat.com;
>> chang.seok.bae@intel.com; pawan.kumar.gupta@linux.intel.com;
>> jmattson@google.com; daniel.sneddon@linux.intel.com; Das1, Sandipan
>> <Sandipan.Das@amd.com>; tony.luck@intel.com; james.morse@arm.com;
>> linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org;
>> bagasdotme@gmail.com; eranian@google.com; christophe.leroy@csgroup.eu;
>> jarkko@kernel.org; adrian.hunter@intel.com; quic_jiles@quicinc.com;
>> peternewman@google.com
>> Subject: Re: [PATCH v4 0/7] x86/resctrl: Miscellaneous resctrl features
>>

...

>>>     Tried to address Reinette's comment on patch 7. But due to current code
>> design
>>>     I could not do it exact way. But changed it little bit to make it easy debug
>>>     file additions in the future.
>>
>> Could you please elaborate? It actually looks like you may be headed there next
>> according to:
>> https://lore.kernel.org/lkml/933d8ae2-d8b7-7436-5918-
>> f639405c9ecb@amd.com/
> 
> Sorry, I was talking about this comment.
> https://lore.kernel.org/lkml/fef12c9e-7d6f-bcd4-f92e-e776eb9e673b@intel.com/
> 
> I tried to address it here. 
> https://lore.kernel.org/lkml/168177451010.1758847.568218491528297451.stgit@bmoger-ubuntu/
> 
> This may not be the exact way you mentioned.  Reason is, adding the
> flags before rdtgroup_add_files cannot be done. It does not update
> the resctrl root filesystem. These files have to added by calling
> rdtgroup_add_file and kernfs_activate in rdt_enable_ctx.
I think what you are referring to is files not appearing in the default
resource group? From what I can tell the files should appear when new resource
groups are created. Could the default resource group's files not also
be added on resctrl mount (moved from rdtgroup_setup_root() to rdt_get_tree())?
I do not see why the files belonging to the default group are required to be
added before resctrl mount and with the move the resctrl_debug flag can
continue to be set in rdt_enable_ctx() and available to rdtgroup_add_files()
when adding the default resource group's files.

To me this sounds simpler since there is no duplicate file add/remove code,
and the debug files are just another file type.

Reinette

[AMD Official Use Only - General]

Hi Reinette,

> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@intel.com>
> Sent: Friday, May 5, 2023 12:47 PM
> To: Moger, Babu <Babu.Moger@amd.com>; corbet@lwn.net;
> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de
> Cc: fenghua.yu@intel.com; dave.hansen@linux.intel.com; x86@kernel.org;
> hpa@zytor.com; paulmck@kernel.org; akpm@linux-foundation.org;
> quic_neeraju@quicinc.com; rdunlap@infradead.org;
> damien.lemoal@opensource.wdc.com; songmuchun@bytedance.com;
> peterz@infradead.org; jpoimboe@kernel.org; pbonzini@redhat.com;
> chang.seok.bae@intel.com; pawan.kumar.gupta@linux.intel.com;
> jmattson@google.com; daniel.sneddon@linux.intel.com; Das1, Sandipan
> <Sandipan.Das@amd.com>; tony.luck@intel.com; james.morse@arm.com;
> linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org;
> bagasdotme@gmail.com; eranian@google.com; christophe.leroy@csgroup.eu;
> jarkko@kernel.org; adrian.hunter@intel.com; quic_jiles@quicinc.com;
> peternewman@google.com
> Subject: Re: [PATCH v4 0/7] x86/resctrl: Miscellaneous resctrl features
> 
> Hi Babu,
> 
> On 5/5/2023 8:43 AM, Moger, Babu wrote:
> > [AMD Official Use Only - General]
> >
> > Hi Reinette,
> >
> >> -----Original Message-----
> >> From: Reinette Chatre <reinette.chatre@intel.com>
> >> Sent: Thursday, May 4, 2023 1:54 PM
> >> To: Moger, Babu <Babu.Moger@amd.com>; corbet@lwn.net;
> >> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de
> >> Cc: fenghua.yu@intel.com; dave.hansen@linux.intel.com;
> >> x86@kernel.org; hpa@zytor.com; paulmck@kernel.org;
> >> akpm@linux-foundation.org; quic_neeraju@quicinc.com;
> >> rdunlap@infradead.org; damien.lemoal@opensource.wdc.com;
> >> songmuchun@bytedance.com; peterz@infradead.org;
> jpoimboe@kernel.org;
> >> pbonzini@redhat.com; chang.seok.bae@intel.com;
> >> pawan.kumar.gupta@linux.intel.com;
> >> jmattson@google.com; daniel.sneddon@linux.intel.com; Das1, Sandipan
> >> <Sandipan.Das@amd.com>; tony.luck@intel.com; james.morse@arm.com;
> >> linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org;
> >> bagasdotme@gmail.com; eranian@google.com;
> >> christophe.leroy@csgroup.eu; jarkko@kernel.org;
> >> adrian.hunter@intel.com; quic_jiles@quicinc.com;
> >> peternewman@google.com
> >> Subject: Re: [PATCH v4 0/7] x86/resctrl: Miscellaneous resctrl
> >> features
> >>
> 
> ...
> 
> >>>     Tried to address Reinette's comment on patch 7. But due to
> >>> current code
> >> design
> >>>     I could not do it exact way. But changed it little bit to make it easy debug
> >>>     file additions in the future.
> >>
> >> Could you please elaborate? It actually looks like you may be headed
> >> there next according to:
> >> https://lore.kernel.org/lkml/933d8ae2-d8b7-7436-5918-
> >> f639405c9ecb@amd.com/
> >
> > Sorry, I was talking about this comment.
> > https://lore.kernel.org/lkml/fef12c9e-7d6f-bcd4-f92e-e776eb9e673b@inte
> > l.com/
> >
> > I tried to address it here.
> > https://lore.kernel.org/lkml/168177451010.1758847.568218491528297451.s
> > tgit@bmoger-ubuntu/
> >
> > This may not be the exact way you mentioned.  Reason is, adding the
> > flags before rdtgroup_add_files cannot be done. It does not update the
> > resctrl root filesystem. These files have to added by calling
> > rdtgroup_add_file and kernfs_activate in rdt_enable_ctx.
> I think what you are referring to is files not appearing in the default resource
> group? From what I can tell the files should appear when new resource groups
> are created. Could the default resource group's files not also be added on
> resctrl mount (moved from rdtgroup_setup_root() to rdt_get_tree())?

Yes. I can try that.

> I do not see why the files belonging to the default group are required to be
> added before resctrl mount and with the move the resctrl_debug flag can
> continue to be set in rdt_enable_ctx() and available to rdtgroup_add_files()
> when adding the default resource group's files.
> 
> To me this sounds simpler since there is no duplicate file add/remove code, and
> the debug files are just another file type.

Yes. If it works then It will make code simple. Will try and let you know.
Thanks
Babu