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From:   Tony Luck <tony.luck@intel.com>
To:     Fenghua Yu <fenghua.yu@intel.com>,
        Reinette Chatre <reinette.chatre@intel.com>,
        Peter Newman <peternewman@google.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Shuah Khan <skhan@linuxfoundation.org>, x86@kernel.org
Cc:     Shaopeng Tan <tan.shaopeng@fujitsu.com>,
        James Morse <james.morse@arm.com>,
        Jamie Iles <quic_jiles@quicinc.com>,
        Babu Moger <babu.moger@amd.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        patches@lists.linux.dev, Tony Luck <tony.luck@intel.com>
Subject: [PATCH v4 6/7] x86/resctrl: Update documentation with Sub-NUMA cluster changes
Date:   Sat, 22 Jul 2023 12:07:39 -0700
Message-Id: <20230722190740.326190-7-tony.luck@intel.com>
In-Reply-To: <20230722190740.326190-1-tony.luck@intel.com>
References: <20230713163207.219710-1-tony.luck@intel.com>
 <20230722190740.326190-1-tony.luck@intel.com>
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With Sub-NUMA Cluster mode enabled the scope of monitoring resources is
per-NODE instead of per-L3 cache. Suffixes of directories with "L3" in
their name refer to Sub-NUMA nodes instead of L3 cache ids.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Peter Newman <peternewman@google.com>
---
 Documentation/arch/x86/resctrl.rst | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index cb05d90111b4..4d9ddb91751d 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -345,9 +345,13 @@ When control is enabled all CTRL_MON groups will also contain:
 When monitoring is enabled all MON groups will also contain:
 
 "mon_data":
-	This contains a set of files organized by L3 domain and by
-	RDT event. E.g. on a system with two L3 domains there will
-	be subdirectories "mon_L3_00" and "mon_L3_01".	Each of these
+	This contains a set of files organized by L3 domain or by NUMA
+	node (depending on whether Sub-NUMA Cluster (SNC) mode is disabled
+	or enabled respectively) and by RDT event. E.g. on a system with
+	SNC mode disabled with two L3 domains there will be subdirectories
+	"mon_L3_00" and "mon_L3_01". The numerical suffix refers to the
+	L3 cache id.  With SNC enabled the directory names are the same,
+	but the numerical suffix refers to the node id.  Each of these
 	directories have one file per event (e.g. "llc_occupancy",
 	"mbm_total_bytes", and "mbm_local_bytes"). In a MON group these
 	files provide a read out of the current value of the event for
-- 
2.40.1