Documentation: x86: convert topology.txt to reST
This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Changbin Du
Jonathan Corbet
Родитель
f1f238a9f1
Коммит
848942cb2e
|
|
@ -9,3 +9,4 @@ x86-specific Documentation
|
|||
:numbered:
|
||||
|
||||
boot
|
||||
topology
|
||||
|
|
|
|||
|
|
@ -1,3 +1,6 @@
|
|||
.. SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
============
|
||||
x86 Topology
|
||||
============
|
||||
|
||||
|
|
@ -33,14 +36,14 @@ The topology of a system is described in the units of:
|
|||
- cores
|
||||
- threads
|
||||
|
||||
* Package:
|
||||
Package
|
||||
=======
|
||||
Packages contain a number of cores plus shared resources, e.g. DRAM
|
||||
controller, shared caches etc.
|
||||
|
||||
Packages contain a number of cores plus shared resources, e.g. DRAM
|
||||
controller, shared caches etc.
|
||||
AMD nomenclature for package is 'Node'.
|
||||
|
||||
AMD nomenclature for package is 'Node'.
|
||||
|
||||
Package-related topology information in the kernel:
|
||||
Package-related topology information in the kernel:
|
||||
|
||||
- cpuinfo_x86.x86_max_cores:
|
||||
|
||||
|
|
@ -66,40 +69,41 @@ The topology of a system is described in the units of:
|
|||
- 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.
|
||||
- On Intel, the first APIC ID of the list of CPUs sharing the Last Level
|
||||
Cache
|
||||
|
||||
* Cores:
|
||||
- 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.
|
||||
|
||||
A core consists of 1 or more threads. It does not matter whether the threads
|
||||
are SMT- or CMT-type threads.
|
||||
Cores
|
||||
=====
|
||||
A core consists of 1 or more threads. It does not matter whether the threads
|
||||
are SMT- or CMT-type threads.
|
||||
|
||||
AMDs nomenclature for a CMT core is "Compute Unit". The kernel always uses
|
||||
"core".
|
||||
AMDs nomenclature for a CMT core is "Compute Unit". The kernel always uses
|
||||
"core".
|
||||
|
||||
Core-related topology information in the kernel:
|
||||
Core-related topology information in the kernel:
|
||||
|
||||
- smp_num_siblings:
|
||||
|
||||
The number of threads in a core. The number of threads in a package can be
|
||||
calculated by:
|
||||
calculated by::
|
||||
|
||||
threads_per_package = cpuinfo_x86.x86_max_cores * smp_num_siblings
|
||||
|
||||
|
||||
* Threads:
|
||||
Threads
|
||||
=======
|
||||
A thread is a single scheduling unit. It's the equivalent to a logical Linux
|
||||
CPU.
|
||||
|
||||
A thread is a single scheduling unit. It's the equivalent to a logical Linux
|
||||
CPU.
|
||||
AMDs nomenclature for CMT threads is "Compute Unit Core". The kernel always
|
||||
uses "thread".
|
||||
|
||||
AMDs nomenclature for CMT threads is "Compute Unit Core". The kernel always
|
||||
uses "thread".
|
||||
|
||||
Thread-related topology information in the kernel:
|
||||
Thread-related topology information in the kernel:
|
||||
|
||||
- topology_core_cpumask():
|
||||
|
||||
|
|
@ -113,15 +117,15 @@ The topology of a system is described in the units of:
|
|||
The cpumask contains all online threads in the core to which a thread
|
||||
belongs.
|
||||
|
||||
- topology_logical_package_id():
|
||||
- topology_logical_package_id():
|
||||
|
||||
The logical package ID to which a thread belongs.
|
||||
|
||||
- topology_physical_package_id():
|
||||
- topology_physical_package_id():
|
||||
|
||||
The physical package ID to which a thread belongs.
|
||||
|
||||
- topology_core_id();
|
||||
- topology_core_id();
|
||||
|
||||
The ID of the core to which a thread belongs. It is also printed in /proc/cpuinfo
|
||||
"core_id."
|
||||
|
|
@ -129,41 +133,41 @@ The topology of a system is described in the units of:
|
|||
|
||||
|
||||
System topology examples
|
||||
========================
|
||||
|
||||
Note:
|
||||
.. note::
|
||||
The alternative Linux CPU enumeration depends on how the BIOS enumerates the
|
||||
threads. Many BIOSes enumerate all threads 0 first and then all threads 1.
|
||||
That has the "advantage" that the logical Linux CPU numbers of threads 0 stay
|
||||
the same whether threads are enabled or not. That's merely an implementation
|
||||
detail and has no practical impact.
|
||||
|
||||
The alternative Linux CPU enumeration depends on how the BIOS enumerates the
|
||||
threads. Many BIOSes enumerate all threads 0 first and then all threads 1.
|
||||
That has the "advantage" that the logical Linux CPU numbers of threads 0 stay
|
||||
the same whether threads are enabled or not. That's merely an implementation
|
||||
detail and has no practical impact.
|
||||
|
||||
1) Single Package, Single Core
|
||||
1) Single Package, Single Core::
|
||||
|
||||
[package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
|
||||
|
||||
2) Single Package, Dual Core
|
||||
|
||||
a) One thread per core
|
||||
a) One thread per core::
|
||||
|
||||
[package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
|
||||
-> [core 1] -> [thread 0] -> Linux CPU 1
|
||||
|
||||
b) Two threads per core
|
||||
b) Two threads per core::
|
||||
|
||||
[package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
|
||||
-> [thread 1] -> Linux CPU 1
|
||||
-> [core 1] -> [thread 0] -> Linux CPU 2
|
||||
-> [thread 1] -> Linux CPU 3
|
||||
|
||||
Alternative enumeration:
|
||||
Alternative enumeration::
|
||||
|
||||
[package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
|
||||
-> [thread 1] -> Linux CPU 2
|
||||
-> [core 1] -> [thread 0] -> Linux CPU 1
|
||||
-> [thread 1] -> Linux CPU 3
|
||||
|
||||
AMD nomenclature for CMT systems:
|
||||
AMD nomenclature for CMT systems::
|
||||
|
||||
[node 0] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 0
|
||||
-> [Compute Unit Core 1] -> Linux CPU 1
|
||||
|
|
@ -172,7 +176,7 @@ detail and has no practical impact.
|
|||
|
||||
4) Dual Package, Dual Core
|
||||
|
||||
a) One thread per core
|
||||
a) One thread per core::
|
||||
|
||||
[package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
|
||||
-> [core 1] -> [thread 0] -> Linux CPU 1
|
||||
|
|
@ -180,7 +184,7 @@ detail and has no practical impact.
|
|||
[package 1] -> [core 0] -> [thread 0] -> Linux CPU 2
|
||||
-> [core 1] -> [thread 0] -> Linux CPU 3
|
||||
|
||||
b) Two threads per core
|
||||
b) Two threads per core::
|
||||
|
||||
[package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
|
||||
-> [thread 1] -> Linux CPU 1
|
||||
|
|
@ -192,7 +196,7 @@ detail and has no practical impact.
|
|||
-> [core 1] -> [thread 0] -> Linux CPU 6
|
||||
-> [thread 1] -> Linux CPU 7
|
||||
|
||||
Alternative enumeration:
|
||||
Alternative enumeration::
|
||||
|
||||
[package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
|
||||
-> [thread 1] -> Linux CPU 4
|
||||
|
|
@ -204,7 +208,7 @@ detail and has no practical impact.
|
|||
-> [core 1] -> [thread 0] -> Linux CPU 3
|
||||
-> [thread 1] -> Linux CPU 7
|
||||
|
||||
AMD nomenclature for CMT systems:
|
||||
AMD nomenclature for CMT systems::
|
||||
|
||||
[node 0] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 0
|
||||
-> [Compute Unit Core 1] -> Linux CPU 1
|
||||
Загрузка…
Ссылка в новой задаче