linux/Documentation/ABI/testing/sysfs-devices-system-cpu

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What: /sys/devices/system/cpu/
Date: pre-git history
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description:
A collection of both global and individual CPU attributes
Individual CPU attributes are contained in subdirectories
named by the kernel's logical CPU number, e.g.:
/sys/devices/system/cpu/cpu#/
What: /sys/devices/system/cpu/kernel_max
/sys/devices/system/cpu/offline
/sys/devices/system/cpu/online
/sys/devices/system/cpu/possible
/sys/devices/system/cpu/present
Date: December 2008
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: CPU topology files that describe kernel limits related to
hotplug. Briefly:
kernel_max: the maximum cpu index allowed by the kernel
configuration.
offline: cpus that are not online because they have been
HOTPLUGGED off or exceed the limit of cpus allowed by the
kernel configuration (kernel_max above).
online: cpus that are online and being scheduled.
possible: cpus that have been allocated resources and can be
brought online if they are present.
present: cpus that have been identified as being present in
the system.
See Documentation/cputopology.txt for more information.
What: /sys/devices/system/cpu/cpu#/topology/core_id
/sys/devices/system/cpu/cpu#/topology/core_siblings
/sys/devices/system/cpu/cpu#/topology/core_siblings_list
/sys/devices/system/cpu/cpu#/topology/physical_package_id
/sys/devices/system/cpu/cpu#/topology/thread_siblings
/sys/devices/system/cpu/cpu#/topology/thread_siblings_list
Date: December 2008
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: CPU topology files that describe a logical CPU's relationship
to other cores and threads in the same physical package.
One cpu# directory is created per logical CPU in the system,
e.g. /sys/devices/system/cpu/cpu42/.
Briefly, the files above are:
core_id: the CPU core ID of cpu#. Typically it is the
hardware platform's identifier (rather than the kernel's).
The actual value is architecture and platform dependent.
core_siblings: internal kernel map of cpu#'s hardware threads
within the same physical_package_id.
core_siblings_list: human-readable list of the logical CPU
numbers within the same physical_package_id as cpu#.
physical_package_id: physical package id of cpu#. Typically
corresponds to a physical socket number, but the actual value
is architecture and platform dependent.
thread_siblings: internel kernel map of cpu#'s hardware
threads within the same core as cpu#
thread_siblings_list: human-readable list of cpu#'s hardware
threads within the same core as cpu#
See Documentation/cputopology.txt for more information.
What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X
Date: August 2008
KernelVersion: 2.6.27
Contact: mark.langsdorf@amd.com
Description: These files exist in every cpu's cache index directories.
There are currently 2 cache_disable_# files in each
directory. Reading from these files on a supported
processor will return that cache disable index value
for that processor and node. Writing to one of these
files will cause the specificed cache index to be disabled.
Currently, only AMD Family 10h Processors support cache index
disable, and only for their L3 caches. See the BIOS and
Kernel Developer's Guide at
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf
for formatting information and other details on the
cache index disable.
Users: joachim.deguara@amd.com