2009-10-22 03:45:20 +00:00
|
|
|
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#/
|
|
|
|
|
2009-10-22 03:45:25 +00:00
|
|
|
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.
|
|
|
|
|
|
|
|
|
2009-11-25 17:23:25 +00:00
|
|
|
What: /sys/devices/system/cpu/probe
|
|
|
|
/sys/devices/system/cpu/release
|
|
|
|
Date: November 2009
|
|
|
|
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
|
|
|
|
Description: Dynamic addition and removal of CPU's. This is not hotplug
|
|
|
|
removal, this is meant complete removal/addition of the CPU
|
|
|
|
from the system.
|
|
|
|
|
|
|
|
probe: writes to this file will dynamically add a CPU to the
|
|
|
|
system. Information written to the file to add CPU's is
|
|
|
|
architecture specific.
|
|
|
|
|
|
|
|
release: writes to this file dynamically remove a CPU from
|
|
|
|
the system. Information writtento the file to remove CPU's
|
|
|
|
is architecture specific.
|
2009-10-22 04:15:30 +00:00
|
|
|
|
2009-12-15 01:59:09 +00:00
|
|
|
What: /sys/devices/system/cpu/cpu#/node
|
|
|
|
Date: October 2009
|
|
|
|
Contact: Linux memory management mailing list <linux-mm@kvack.org>
|
|
|
|
Description: Discover NUMA node a CPU belongs to
|
|
|
|
|
|
|
|
When CONFIG_NUMA is enabled, a symbolic link that points
|
|
|
|
to the corresponding NUMA node directory.
|
|
|
|
|
|
|
|
For example, the following symlink is created for cpu42
|
|
|
|
in NUMA node 2:
|
|
|
|
|
|
|
|
/sys/devices/system/cpu/cpu42/node2 -> ../../node/node2
|
|
|
|
|
|
|
|
|
2009-10-22 03:45:31 +00:00
|
|
|
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.
|
|
|
|
|
|
|
|
|
2009-10-22 03:45:41 +00:00
|
|
|
What: /sys/devices/system/cpu/cpuidle/current_driver
|
|
|
|
/sys/devices/system/cpu/cpuidle/current_governer_ro
|
|
|
|
Date: September 2007
|
|
|
|
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
|
|
|
|
Description: Discover cpuidle policy and mechanism
|
|
|
|
|
|
|
|
Various CPUs today support multiple idle levels that are
|
|
|
|
differentiated by varying exit latencies and power
|
|
|
|
consumption during idle.
|
|
|
|
|
|
|
|
Idle policy (governor) is differentiated from idle mechanism
|
|
|
|
(driver)
|
|
|
|
|
|
|
|
current_driver: displays current idle mechanism
|
|
|
|
|
|
|
|
current_governor_ro: displays current idle policy
|
|
|
|
|
|
|
|
See files in Documentation/cpuidle/ for more information.
|
|
|
|
|
|
|
|
|
2009-10-22 03:45:46 +00:00
|
|
|
What: /sys/devices/system/cpu/cpu#/cpufreq/*
|
|
|
|
Date: pre-git history
|
|
|
|
Contact: cpufreq@vger.kernel.org
|
|
|
|
Description: Discover and change clock speed of CPUs
|
|
|
|
|
|
|
|
Clock scaling allows you to change the clock speed of the
|
|
|
|
CPUs on the fly. This is a nice method to save battery
|
|
|
|
power, because the lower the clock speed, the less power
|
|
|
|
the CPU consumes.
|
|
|
|
|
|
|
|
There are many knobs to tweak in this directory.
|
|
|
|
|
|
|
|
See files in Documentation/cpu-freq/ for more information.
|
|
|
|
|
|
|
|
In particular, read Documentation/cpu-freq/user-guide.txt
|
|
|
|
to learn how to control the knobs.
|
|
|
|
|
|
|
|
|
2013-06-27 07:08:54 +00:00
|
|
|
What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus
|
|
|
|
Date: June 2013
|
|
|
|
Contact: cpufreq@vger.kernel.org
|
|
|
|
Description: Discover CPUs in the same CPU frequency coordination domain
|
|
|
|
|
|
|
|
freqdomain_cpus is the list of CPUs (online+offline) that share
|
|
|
|
the same clock/freq domain (possibly at the hardware level).
|
|
|
|
That information may be hidden from the cpufreq core and the
|
|
|
|
value of related_cpus may be different from freqdomain_cpus. This
|
|
|
|
attribute is useful for user space DVFS controllers to get better
|
|
|
|
power/performance results for platforms using acpi-cpufreq.
|
|
|
|
|
|
|
|
This file is only present if the acpi-cpufreq driver is in use.
|
|
|
|
|
|
|
|
|
2011-05-16 13:39:48 +00:00
|
|
|
What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
|
|
|
|
Date: August 2008
|
2009-04-09 13:31:53 +00:00
|
|
|
KernelVersion: 2.6.27
|
2011-05-16 13:39:48 +00:00
|
|
|
Contact: discuss@x86-64.org
|
|
|
|
Description: Disable L3 cache indices
|
|
|
|
|
|
|
|
These files exist in every CPU's cache/index3 directory. Each
|
|
|
|
cache_disable_{0,1} file corresponds to one disable slot which
|
|
|
|
can be used to disable a cache index. Reading from these files
|
|
|
|
on a processor with this functionality will return the currently
|
|
|
|
disabled index for that node. There is one L3 structure per
|
|
|
|
node, or per internal node on MCM machines. Writing a valid
|
|
|
|
index to one of these files will cause the specificed cache
|
|
|
|
index to be disabled.
|
|
|
|
|
|
|
|
All AMD processors with L3 caches provide this functionality.
|
|
|
|
For details, see BKDGs at
|
|
|
|
http://developer.amd.com/documentation/guides/Pages/default.aspx
|
2012-09-04 08:28:07 +00:00
|
|
|
|
|
|
|
|
|
|
|
What: /sys/devices/system/cpu/cpufreq/boost
|
|
|
|
Date: August 2012
|
|
|
|
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
|
|
|
|
Description: Processor frequency boosting control
|
|
|
|
|
|
|
|
This switch controls the boost setting for the whole system.
|
|
|
|
Boosting allows the CPU and the firmware to run at a frequency
|
|
|
|
beyound it's nominal limit.
|
|
|
|
More details can be found in Documentation/cpu-freq/boost.txt
|
2013-03-28 08:16:45 +00:00
|
|
|
|
|
|
|
|
|
|
|
What: /sys/devices/system/cpu/cpu#/crash_notes
|
|
|
|
/sys/devices/system/cpu/cpu#/crash_notes_size
|
|
|
|
Date: April 2013
|
|
|
|
Contact: kexec@lists.infradead.org
|
|
|
|
Description: address and size of the percpu note.
|
|
|
|
|
|
|
|
crash_notes: the physical address of the memory that holds the
|
|
|
|
note of cpu#.
|
|
|
|
|
|
|
|
crash_notes_size: size of the note of cpu#.
|