[PATCH] x86/topology: Document cpu_llc_id

[PATCH] x86/topology: Document cpu_llc_id

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

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

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 Documentation/x86/topology.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
index 06afac252f5b..7a5485730476 100644
--- a/Documentation/x86/topology.txt
+++ b/Documentation/x86/topology.txt
@@ -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:
 
-- 
2.10.0

Re: [PATCH] x86/topology: Document cpu_llc_id

[Peter Zijlstra]

On Wed, Sep 07, 2016 at 11:22:19AM +0200, Borislav Petkov wrote:
> From: Borislav Petkov <bp@suse.de>
> 
> It means different things on Intel and AMD so write it down so that
> there's no confusion.
> 
> Signed-off-by: Borislav Petkov <bp@suse.de>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> ---
>  Documentation/x86/topology.txt | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
> index 06afac252f5b..7a5485730476 100644
> --- a/Documentation/x86/topology.txt
> +++ b/Documentation/x86/topology.txt
> @@ -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?

Re: [PATCH] x86/topology: Document cpu_llc_id

[Borislav Petkov]

On Wed, Sep 07, 2016 at 12:36:41PM +0200, Peter Zijlstra wrote:
> On Wed, Sep 07, 2016 at 11:22:19AM +0200, Borislav Petkov wrote:
> > From: Borislav Petkov <bp@suse.de>
> > 
> > It means different things on Intel and AMD so write it down so that
> > there's no confusion.
> > 
> > Signed-off-by: Borislav Petkov <bp@suse.de>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > ---
> >  Documentation/x86/topology.txt | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
> > index 06afac252f5b..7a5485730476 100644
> > --- a/Documentation/x86/topology.txt
> > +++ b/Documentation/x86/topology.txt
> > @@ -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?

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?

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

[PATCH -v1.1] x86/topology: Document cpu_llc_id

[Borislav Petkov]

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

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
index 06afac252f5b..f3e9d7e9ed6c 100644
--- a/Documentation/x86/topology.txt
+++ b/Documentation/x86/topology.txt
@@ -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:
 
-- 
2.10.0


-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

Re: [PATCH -v1.1] x86/topology: Document cpu_llc_id

[Yazen Ghannam]

On Thu, Nov 17, 2016 at 10:45:57AM +0100, Borislav Petkov wrote:
> It means different things on Intel and AMD so write it down so that
> there's no confusion.
> 
> Signed-off-by: Borislav Petkov <bp@suse.de>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Yazen Ghannam <yazen.ghannam@amd.com>
> ---
>  Documentation/x86/topology.txt | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
> index 06afac252f5b..f3e9d7e9ed6c 100644
> --- a/Documentation/x86/topology.txt
> +++ b/Documentation/x86/topology.txt
> @@ -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:
> 

Look good to me.

Thanks,
Yazen 

Re: [PATCH -v1.1] x86/topology: Document cpu_llc_id

[Borislav Petkov]

On Thu, Nov 17, 2016 at 07:57:11AM -0500, Yazen Ghannam wrote:
> Look good to me.

We normally say that with:

Acked-by: "name" <email@address>

:-)

Thanks.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

[tip:x86/urgent] x86/topology: Document cpu_llc_id

[tip-bot for Borislav Petkov]

Commit-ID:  dbf12ae564c022a741a6983b2bb4aeea5b8c0efd
Gitweb:     http://git.kernel.org/tip/dbf12ae564c022a741a6983b2bb4aeea5b8c0efd
Author:     Borislav Petkov <bp@alien8.de>
AuthorDate: Thu, 17 Nov 2016 10:45:57 +0100
Committer:  Thomas Gleixner <tglx@linutronix.de>
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.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20161117094557.jm6hwzdd52h7iwnj@pd.tnic
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
index 06afac2..f3e9d7e 100644
--- a/Documentation/x86/topology.txt
+++ b/Documentation/x86/topology.txt
@@ -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:
 

[tip:x86/urgent] x86/topology: Document cpu_llc_id

[tip-bot for Borislav Petkov]

Commit-ID:  a268b5f1d6e4639fa6d78fc8bdddaebaa032ab24
Gitweb:     http://git.kernel.org/tip/a268b5f1d6e4639fa6d78fc8bdddaebaa032ab24
Author:     Borislav Petkov <bp@alien8.de>
AuthorDate: Thu, 17 Nov 2016 10:45:57 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
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.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20161117094557.jm6hwzdd52h7iwnj@pd.tnic
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 Documentation/x86/topology.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
index 06afac2..f3e9d7e 100644
--- a/Documentation/x86/topology.txt
+++ b/Documentation/x86/topology.txt
@@ -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: