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x86/topology: Document cpu_llc_id

PATCH In review Borislav Petkov 4 participants 8 messages Sep 7, 2016 – Dec 20, 2016 Documentation

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#0 lore raw

PATCH 1/1 x86/topology: Document cpu_llc_id

From: Borislav Petkov <[email protected]>

It means different things on Intel and AMD so write it down so that there's no confusion.

Cc Peter Zijlstra <[email protected]>
Cc Thomas Gleixner <[email protected]>
---
 Documentation/x86/topology.txt | 6 ++++++
 1 file changed, 6 insertions(+)
Documentation/x86/topology.txt +6 -0
index 06afac252f5b..7a5485730476 100644
@@ -63,6 +63,12 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
+  - cpu_llc_id:
+
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+    - On AMD, the Node ID containing the Last Level Cache.
 
 * Cores:
 
Signature · 1 line
2.10.0
#1 lore raw
Quoted 17 lines · Borislav Petkov

From: Borislav Petkov <[email protected]>

It means different things on Intel and AMD so write it down so that there's no confusion.

Cc Peter Zijlstra <[email protected]>
Cc Thomas Gleixner <[email protected]>
---
 Documentation/x86/topology.txt | 6 ++++++
 1 file changed, 6 insertions(+)
Documentation/x86/topology.txt +0 -0
index 06afac252f5b..7a5485730476 100644

Documentation/x86/topology.txt The topology of a system is described in the units of: · line 71

Quoted 9 lines
Documentation/x86/topology.txt +6 -0
@@ -63,6 +63,12 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
+  - cpu_llc_id:
+
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+    - On AMD, the Node ID containing the Last Level Cache.

And there are no AMD parts where there are multiple LLCs on a Node? Like where there isn't an L3 and the L2 is only per cluster?

#2 lore raw
Quoted 21 lines · Peter Zijlstra
Quoted 20 lines · Borislav Petkov

From: Borislav Petkov <[email protected]>

It means different things on Intel and AMD so write it down so that there's no confusion.

Cc Peter Zijlstra <[email protected]>
Cc Thomas Gleixner <[email protected]>
---
 Documentation/x86/topology.txt | 6 ++++++
 1 file changed, 6 insertions(+)
Documentation/x86/topology.txt +0 -0
index 06afac252f5b..7a5485730476 100644
@@ -63,6 +63,12 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
Quoted 9 lines

Documentation/x86/topology.txt The topology of a system is described in the units of: · line 71

Quoted 6 lines
Documentation/x86/topology.txt +6 -0
+  - cpu_llc_id:
+
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+    - On AMD, the Node ID containing the Last Level Cache.

And there are no AMD parts where there are multiple LLCs on a Node? Like where there isn't an L3 and the L2 is only per cluster?

Yes there are (now), see:

http://git.kernel.org/tip/b0b6e86846093c5f8820386bc01515f857dd8faa

But those LLC ID numbers are still increasing IDs of either nodes or core complexes in Zen's case. So I think the text should say:

"- On AMD, the Node ID or Core Complex ID containing the Last Level Cache. In
general, numbers identifying an LLC uniquely on the system."

How's that?

Signature · 4 lines
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.
#3 lore raw

PATCH 1/1 x86/topology: Document cpu_llc_id

It means different things on Intel and AMD so write it down so that there's no confusion.

Cc Peter Zijlstra <[email protected]>
Cc Thomas Gleixner <[email protected]>
Cc Yazen Ghannam <[email protected]>
---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)
Documentation/x86/topology.txt +9 -0
index 06afac252f5b..f3e9d7e9ed6c 100644
@@ -63,6 +63,15 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
+  - cpu_llc_id:
+
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+
+    - On AMD, the Node ID or Core Complex ID containing the Last Level
+    Cache. In general, it is a number identifying an LLC uniquely on the
+    system.
 
 * Cores:
 
Signature · 8 lines
2.10.0


-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.
#4 lore raw
Quoted 21 lines · Borislav Petkov

It means different things on Intel and AMD so write it down so that there's no confusion.

Cc Peter Zijlstra <[email protected]>
Cc Thomas Gleixner <[email protected]>
Cc Yazen Ghannam <[email protected]>
---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)
Documentation/x86/topology.txt +2 -0
index 06afac252f5b..f3e9d7e9ed6c 100644
@@ -63,6 +63,15 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
+  - cpu_llc_id:
+

Documentation/x86/topology.txt The topology of a system is described in the units of: · line 77

Quoted 10 lines
Documentation/x86/topology.txt +7 -0
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+
+    - On AMD, the Node ID or Core Complex ID containing the Last Level
+    Cache. In general, it is a number identifying an LLC uniquely on the
+    system.
 
 * Cores:
 

Look good to me.

Thanks,
Yazen

author Acked-by name
#5 lore raw
Quoted 1 line · Yazen Ghannam

Look good to me.

We normally say that with:

:-)

Thanks.

Signature · 4 lines
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.
#6 lore raw
In reply to Borislav Petkov
x86/topology: Document cpu_llc_id
Commit-ID:  dbf12ae564c022a741a6983b2bb4aeea5b8c0efd
Gitweb:     http://git.kernel.org/tip/dbf12ae564c022a741a6983b2bb4aeea5b8c0efd
Author:     Borislav Petkov <[email protected]>
AuthorDate: Thu, 17 Nov 2016 10:45:57 +0100
Committer:  Thomas Gleixner <[email protected]>
CommitDate: Mon, 19 Dec 2016 12:27:53 +0100

x86/topology: Document cpu_llc_id

It means different things on Intel and AMD so write it down so that there's no confusion.

---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)
Documentation/x86/topology.txt +9 -0
index 06afac2..f3e9d7e 100644
@@ -63,6 +63,15 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
+  - cpu_llc_id:
+
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+
+    - On AMD, the Node ID or Core Complex ID containing the Last Level
+    Cache. In general, it is a number identifying an LLC uniquely on the
+    system.
 
 * Cores:
 
#7 lore raw
In reply to Borislav Petkov
x86/topology: Document cpu_llc_id
Commit-ID:  a268b5f1d6e4639fa6d78fc8bdddaebaa032ab24
Gitweb:     http://git.kernel.org/tip/a268b5f1d6e4639fa6d78fc8bdddaebaa032ab24
Author:     Borislav Petkov <[email protected]>
AuthorDate: Thu, 17 Nov 2016 10:45:57 +0100
Committer:  Ingo Molnar <[email protected]>
CommitDate: Tue, 20 Dec 2016 09:36:29 +0100

x86/topology: Document cpu_llc_id

It means different things on Intel and AMD so write it down so that there's no confusion.

---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)
Documentation/x86/topology.txt +9 -0
index 06afac2..f3e9d7e 100644
@@ -63,6 +63,15 @@ The topology of a system is described in the units of:
     The maximum possible number of packages in the system. Helpful for per
     package facilities to preallocate per package information.
 
+  - cpu_llc_id:
+
+    A per-CPU variable containing:
+    - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
+    Cache
+
+    - On AMD, the Node ID or Core Complex ID containing the Last Level
+    Cache. In general, it is a number identifying an LLC uniquely on the
+    system.
 
 * Cores: