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authorLen Brown <len.brown@intel.com>2019-02-26 09:20:00 +0300
committerIngo Molnar <mingo@kernel.org>2019-04-19 11:56:04 +0300
commit3a1c779fb8f71e772e2145e68c262936ada815ed (patch)
tree1efb530b7f09ffb3427c6cd042fdc4384e3030c2 /Documentation/cputopology.txt
parentef7c7727f2c18338fa77b339f10ab923a4c0b0f4 (diff)
downloadlinux-3a1c779fb8f71e772e2145e68c262936ada815ed.tar.xz
topology: Simplify cputopology.txt formatting and wording
Syntax only, no functional or semantic change. Signed-off-by: Len Brown <len.brown@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/1ca56f8ea922a67f0017bd645912ea02a65a85ec.1551160674.git.len.brown@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/cputopology.txt')
-rw-r--r--Documentation/cputopology.txt46
1 files changed, 23 insertions, 23 deletions
diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt
index c6e7e9196a8b..cb61277e2308 100644
--- a/Documentation/cputopology.txt
+++ b/Documentation/cputopology.txt
@@ -3,79 +3,79 @@ How CPU topology info is exported via sysfs
===========================================
Export CPU topology info via sysfs. Items (attributes) are similar
-to /proc/cpuinfo output of some architectures:
+to /proc/cpuinfo output of some architectures. They reside in
+/sys/devices/system/cpu/cpuX/topology/:
-1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
+physical_package_id:
physical package id of cpuX. Typically corresponds to a physical
socket number, but the actual value is architecture and platform
dependent.
-2) /sys/devices/system/cpu/cpuX/topology/core_id:
+core_id:
the CPU core ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
-3) /sys/devices/system/cpu/cpuX/topology/book_id:
+book_id:
the book ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
-4) /sys/devices/system/cpu/cpuX/topology/drawer_id:
+drawer_id:
the drawer ID of cpuX. Typically it is the hardware platform's
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
-5) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
+thread_siblings:
internal kernel map of cpuX's hardware threads within the same
core as cpuX.
-6) /sys/devices/system/cpu/cpuX/topology/thread_siblings_list:
+thread_siblings_list:
human-readable list of cpuX's hardware threads within the same
core as cpuX.
-7) /sys/devices/system/cpu/cpuX/topology/core_siblings:
+core_siblings:
internal kernel map of cpuX's hardware threads within the same
physical_package_id.
-8) /sys/devices/system/cpu/cpuX/topology/core_siblings_list:
+core_siblings_list:
human-readable list of cpuX's hardware threads within the same
physical_package_id.
-9) /sys/devices/system/cpu/cpuX/topology/book_siblings:
+book_siblings:
internal kernel map of cpuX's hardware threads within the same
book_id.
-10) /sys/devices/system/cpu/cpuX/topology/book_siblings_list:
+book_siblings_list:
human-readable list of cpuX's hardware threads within the same
book_id.
-11) /sys/devices/system/cpu/cpuX/topology/drawer_siblings:
+drawer_siblings:
internal kernel map of cpuX's hardware threads within the same
drawer_id.
-12) /sys/devices/system/cpu/cpuX/topology/drawer_siblings_list:
+drawer_siblings_list:
human-readable list of cpuX's hardware threads within the same
drawer_id.
-To implement it in an architecture-neutral way, a new source file,
-drivers/base/topology.c, is to export the 6 to 12 attributes. The book
-and drawer related sysfs files will only be created if CONFIG_SCHED_BOOK
-and CONFIG_SCHED_DRAWER are selected.
+Architecture-neutral, drivers/base/topology.c, exports these attributes.
+However, the book and drawer related sysfs files will only be created if
+CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are selected, respectively.
-CONFIG_SCHED_BOOK and CONFIG_DRAWER are currently only used on s390, where
-they reflect the cpu and cache hierarchy.
+CONFIG_SCHED_BOOK and CONFIG_SCHED_DRAWER are currently only used on s390,
+where they reflect the cpu and cache hierarchy.
For an architecture to support this feature, it must define some of
these macros in include/asm-XXX/topology.h::
@@ -98,10 +98,10 @@ To be consistent on all architectures, include/linux/topology.h
provides default definitions for any of the above macros that are
not defined by include/asm-XXX/topology.h:
-1) physical_package_id: -1
-2) core_id: 0
-3) sibling_cpumask: just the given CPU
-4) core_cpumask: just the given CPU
+1) topology_physical_package_id: -1
+2) topology_core_id: 0
+3) topology_sibling_cpumask: just the given CPU
+4) topology_core_cpumask: just the given CPU
For architectures that don't support books (CONFIG_SCHED_BOOK) there are no
default definitions for topology_book_id() and topology_book_cpumask().