RE: [PATCH v4 0/7] x86/resctrl: Miscellaneous resctrl features

Moger, Babu
2023-05-05T18:03:30Z

[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