Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) client-ip=2620:137:e000::3:2;
MIME-Version: 1.0
References: <20230915224227.1336967-1-babu.moger@amd.com> <20230915224227.1336967-11-babu.moger@amd.com>
In-Reply-To: <20230915224227.1336967-11-babu.moger@amd.com>
From:   Peter Newman <peternewman@google.com>
Date:   Fri, 22 Sep 2023 16:36:20 +0200
Message-ID: <CALPaoCj46dDCFruHW3EcqRQ90SZpOsKK2UVPzb+88rzs5aTTJg@mail.gmail.com>
Subject: Re: [PATCH v10 10/10] x86/resctrl: Display RMID of resource group
To:     Babu Moger <babu.moger@amd.com>
Cc:     corbet@lwn.net, reinette.chatre@intel.com, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de, 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,
        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
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi Babu,

On Sat, Sep 16, 2023 at 12:42=E2=80=AFAM Babu Moger <babu.moger@amd.com> wr=
ote:
>
> In x86, hardware uses RMID to identify a monitoring group. When a user
> creates a monitor group these details are not visible. These details
> can help resctrl debugging.
>
> Add RMID(mon_hw_id) to the monitor groups display in resctrl interface.
> Users can see these details when resctrl is mounted with "-o debug" optio=
n.

When I reviewed this, I went through the whole series second-guessing
the wording above and wondering whether "monitoring groups" applied to
CTRL_MON groups.

I was able to confirm that mon_hw_id did appear and had a believable
value in CTRL_MON groups which had allocated monitors. (and I added
some comma-separated PID lists to the tasks node)

for the series:
Tested-By: Peter Newman <peternewman@google.com>

> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu=
/resctrl/internal.h
> index a07fa4329b65..b4910892b0a6 100644
> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -296,6 +296,11 @@ struct rdtgroup {
>   *     --> RFTYPE_BASE (Files common for both MON and CTRL groups)
>   *         Files: cpus, cpus_list, tasks
>   *
> + *             --> RFTYPE_MON (Files only for MON group)

If monitoring is supported, all groups are MON groups. I think the
"only" above caused me to second guess whether this takes into account
CTRL_MON groups getting the RFTYPE_MON flag set dynamically.

However, I think the documentation above is still technically accurate.

for the series:
Reviewed-By: Peter Newman <peternewman@google.com>

Thanks!
-Peter