diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-system-cpu')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 317 |
1 files changed, 218 insertions, 99 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index fc20cde63d1e..a1db6db47505 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -7,7 +7,7 @@ Description: Individual CPU attributes are contained in subdirectories named by the kernel's logical CPU number, e.g.: - /sys/devices/system/cpu/cpu#/ + /sys/devices/system/cpu/cpuX/ What: /sys/devices/system/cpu/kernel_max /sys/devices/system/cpu/offline @@ -50,10 +50,10 @@ Description: Dynamic addition and removal of CPU's. This is not hotplug architecture specific. release: writes to this file dynamically remove a CPU from - the system. Information writtento the file to remove CPU's + the system. Information written to the file to remove CPU's is architecture specific. -What: /sys/devices/system/cpu/cpu#/node +What: /sys/devices/system/cpu/cpuX/node Date: October 2009 Contact: Linux memory management mailing list <linux-mm@kvack.org> Description: Discover NUMA node a CPU belongs to @@ -67,49 +67,50 @@ Description: Discover NUMA node a CPU belongs to /sys/devices/system/cpu/cpu42/node2 -> ../../node/node2 -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 +What: /sys/devices/system/cpu/cpuX/topology/core_siblings + /sys/devices/system/cpu/cpuX/topology/core_siblings_list + /sys/devices/system/cpu/cpuX/topology/physical_package_id + /sys/devices/system/cpu/cpuX/topology/thread_siblings + /sys/devices/system/cpu/cpuX/topology/thread_siblings_list + /sys/devices/system/cpu/cpuX/topology/ppin 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, + One cpuX 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 + core_siblings: internal kernel map of cpuX'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#. + numbers within the same physical_package_id as cpuX. - physical_package_id: physical package id of cpu#. Typically + physical_package_id: physical package id of cpuX. 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: internal kernel map of cpuX's hardware + threads within the same core as cpuX + + thread_siblings_list: human-readable list of cpuX's hardware + threads within the same core as cpuX - thread_siblings_list: human-readable list of cpu#'s hardware - threads within the same core as cpu# + ppin: human-readable Protected Processor Identification + Number of the socket the cpu# belongs to. There should be + one per physical_package_id. File is readable only to + admin. See Documentation/admin-guide/cputopology.rst for more information. -What: /sys/devices/system/cpu/cpuidle/current_driver - /sys/devices/system/cpu/cpuidle/current_governer_ro - /sys/devices/system/cpu/cpuidle/available_governors +What: /sys/devices/system/cpu/cpuidle/available_governors + /sys/devices/system/cpu/cpuidle/current_driver /sys/devices/system/cpu/cpuidle/current_governor + /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 @@ -119,29 +120,23 @@ Description: Discover cpuidle policy and mechanism consumption during idle. Idle policy (governor) is differentiated from idle mechanism - (driver) - - current_driver: (RO) displays current idle mechanism - - current_governor_ro: (RO) displays current idle policy - - With the cpuidle_sysfs_switch boot option enabled (meant for - developer testing), the following three attributes are visible - instead: - - current_driver: same as described above + (driver). available_governors: (RO) displays a space separated list of - available governors + available governors. + + current_driver: (RO) displays current idle mechanism. current_governor: (RW) displays current idle policy. Users can switch the governor at runtime by writing to this file. + current_governor_ro: (RO) displays current idle policy. + See Documentation/admin-guide/pm/cpuidle.rst and Documentation/driver-api/pm/cpuidle.rst for more information. -What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/name +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/name /sys/devices/system/cpu/cpuX/cpuidle/stateN/latency /sys/devices/system/cpu/cpuX/cpuidle/stateN/power /sys/devices/system/cpu/cpuX/cpuidle/stateN/time @@ -157,25 +152,30 @@ Description: The processor idle states which are available for use have the following attributes: - name: (RO) Name of the idle state (string). + ======== ==== ================================================= + name: (RO) Name of the idle state (string). latency: (RO) The latency to exit out of this idle state (in - microseconds). + microseconds). - power: (RO) The power consumed while in this idle state (in - milliwatts). + power: (RO) The power consumed while in this idle state (in + milliwatts). - time: (RO) The total time spent in this idle state (in microseconds). + time: (RO) The total time spent in this idle state + (in microseconds). - usage: (RO) Number of times this state was entered (a count). + usage: (RO) Number of times this state was entered (a count). - above: (RO) Number of times this state was entered, but the - observed CPU idle duration was too short for it (a count). + above: (RO) Number of times this state was entered, but the + observed CPU idle duration was too short for it + (a count). - below: (RO) Number of times this state was entered, but the - observed CPU idle duration was too long for it (a count). + below: (RO) Number of times this state was entered, but the + observed CPU idle duration was too long for it + (a count). + ======== ==== ================================================= -What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/desc +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/desc Date: February 2008 KernelVersion: v2.6.25 Contact: Linux power management list <linux-pm@vger.kernel.org> @@ -183,7 +183,7 @@ Description: (RO) A small description about the idle state (string). -What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/disable +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/disable Date: March 2012 KernelVersion: v3.10 Contact: Linux power management list <linux-pm@vger.kernel.org> @@ -196,8 +196,14 @@ Description: does not reflect it. Likewise, if one enables a deep state but a lighter state still is disabled, then this has no effect. +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/default_status +Date: December 2019 +KernelVersion: v5.6 +Contact: Linux power management list <linux-pm@vger.kernel.org> +Description: + (RO) The default status of this state, "enabled" or "disabled". -What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/residency Date: March 2014 KernelVersion: v3.15 Contact: Linux power management list <linux-pm@vger.kernel.org> @@ -206,7 +212,7 @@ Description: time (in microseconds) this cpu should spend in this idle state to make the transition worth the effort. -What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/ +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/s2idle/ Date: March 2018 KernelVersion: v4.17 Contact: Linux power management list <linux-pm@vger.kernel.org> @@ -216,7 +222,7 @@ Description: This attribute group is only present for states that can be used in suspend-to-idle with suspended timekeeping. -What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/time +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/s2idle/time Date: March 2018 KernelVersion: v4.17 Contact: Linux power management list <linux-pm@vger.kernel.org> @@ -224,7 +230,7 @@ Description: Total time spent by the CPU in suspend-to-idle (with scheduler tick suspended) after requesting this state. -What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/usage +What: /sys/devices/system/cpu/cpuX/cpuidle/state<N>/s2idle/usage Date: March 2018 KernelVersion: v4.17 Contact: Linux power management list <linux-pm@vger.kernel.org> @@ -232,7 +238,7 @@ Description: Total number of times this state has been requested by the CPU while entering suspend-to-idle. -What: /sys/devices/system/cpu/cpu#/cpufreq/* +What: /sys/devices/system/cpu/cpuX/cpufreq/* Date: pre-git history Contact: linux-pm@vger.kernel.org Description: Discover and change clock speed of CPUs @@ -247,7 +253,7 @@ Description: Discover and change clock speed of CPUs See files in Documentation/cpu-freq/ for more information. -What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus +What: /sys/devices/system/cpu/cpuX/cpufreq/freqdomain_cpus Date: June 2013 Contact: linux-pm@vger.kernel.org Description: Discover CPUs in the same CPU frequency coordination domain @@ -259,7 +265,8 @@ Description: Discover CPUs in the same CPU frequency coordination domain 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. + This file is only present if the acpi-cpufreq or the cppc-cpufreq + drivers are in use. What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1} @@ -274,12 +281,12 @@ Description: Disable L3 cache indices 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 one of these files will cause the specified 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 + https://www.amd.com/en/support/tech-docs?keyword=bios+kernel What: /sys/devices/system/cpu/cpufreq/boost @@ -289,21 +296,22 @@ 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. + beyond its nominal limit. + More details can be found in Documentation/admin-guide/pm/cpufreq.rst -What: /sys/devices/system/cpu/cpu#/crash_notes - /sys/devices/system/cpu/cpu#/crash_notes_size +What: /sys/devices/system/cpu/cpuX/crash_notes + /sys/devices/system/cpu/cpuX/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#. + note of cpuX. - crash_notes_size: size of the note of cpu#. + crash_notes_size: size of the note of cpuX. What: /sys/devices/system/cpu/intel_pstate/max_perf_pct @@ -337,43 +345,54 @@ Contact: Sudeep Holla <sudeep.holla@arm.com> Description: Parameters for the CPU cache attributes allocation_policy: - - WriteAllocate: allocate a memory location to a cache line - on a cache miss because of a write - - ReadAllocate: allocate a memory location to a cache line + - WriteAllocate: + allocate a memory location to a cache line + on a cache miss because of a write + - ReadAllocate: + allocate a memory location to a cache line on a cache miss because of a read - - ReadWriteAllocate: both writeallocate and readallocate + - ReadWriteAllocate: + both writeallocate and readallocate - attributes: LEGACY used only on IA64 and is same as write_policy - - coherency_line_size: the minimum amount of data in bytes that gets + coherency_line_size: + the minimum amount of data in bytes that gets transferred from memory to cache - level: the cache hierarchy in the multi-level cache configuration + level: + the cache hierarchy in the multi-level cache configuration - number_of_sets: total number of sets in the cache, a set is a + number_of_sets: + total number of sets in the cache, a set is a collection of cache lines with the same cache index - physical_line_partition: number of physical cache line per cache tag + physical_line_partition: + number of physical cache line per cache tag - shared_cpu_list: the list of logical cpus sharing the cache + shared_cpu_list: + the list of logical cpus sharing the cache - shared_cpu_map: logical cpu mask containing the list of cpus sharing + shared_cpu_map: + logical cpu mask containing the list of cpus sharing the cache - size: the total cache size in kB + size: + the total cache size in kB type: - Instruction: cache that only holds instructions - Data: cache that only caches data - Unified: cache that holds both data and instructions - ways_of_associativity: degree of freedom in placing a particular block - of memory in the cache + ways_of_associativity: + degree of freedom in placing a particular block + of memory in the cache write_policy: - - WriteThrough: data is written to both the cache line + - WriteThrough: + data is written to both the cache line and to the block in the lower-level memory - - WriteBack: data is written only to the cache line and + - WriteBack: + data is written only to the cache line and the modified cache line is written to main memory only when it is replaced @@ -414,30 +433,30 @@ Description: POWERNV CPUFreq driver's frequency throttle stats directory and throttle attributes exported in the 'throttle_stats' directory: - turbo_stat : This file gives the total number of times the max - frequency is throttled to lower frequency in turbo (at and above - nominal frequency) range of frequencies. + frequency is throttled to lower frequency in turbo (at and above + nominal frequency) range of frequencies. - sub_turbo_stat : This file gives the total number of times the - max frequency is throttled to lower frequency in sub-turbo(below - nominal frequency) range of frequencies. + max frequency is throttled to lower frequency in sub-turbo(below + nominal frequency) range of frequencies. - unthrottle : This file gives the total number of times the max - frequency is unthrottled after being throttled. + frequency is unthrottled after being throttled. - powercap : This file gives the total number of times the max - frequency is throttled due to 'Power Capping'. + frequency is throttled due to 'Power Capping'. - overtemp : This file gives the total number of times the max - frequency is throttled due to 'CPU Over Temperature'. + frequency is throttled due to 'CPU Over Temperature'. - supply_fault : This file gives the total number of times the - max frequency is throttled due to 'Power Supply Failure'. + max frequency is throttled due to 'Power Supply Failure'. - overcurrent : This file gives the total number of times the - max frequency is throttled due to 'Overcurrent'. + max frequency is throttled due to 'Overcurrent'. - occ_reset : This file gives the total number of times the max - frequency is throttled due to 'OCC Reset'. + frequency is throttled due to 'OCC Reset'. The sysfs attributes representing different throttle reasons like powercap, overtemp, supply_fault, overcurrent and occ_reset map to @@ -466,28 +485,43 @@ What: /sys/devices/system/cpu/cpuX/regs/ /sys/devices/system/cpu/cpuX/regs/identification/ /sys/devices/system/cpu/cpuX/regs/identification/midr_el1 /sys/devices/system/cpu/cpuX/regs/identification/revidr_el1 + /sys/devices/system/cpu/cpuX/regs/identification/smidr_el1 Date: June 2016 Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> Description: AArch64 CPU registers + 'identification' directory exposes the CPU ID registers for - identifying model and revision of the CPU. + identifying model and revision of the CPU and SMCU. -What: /sys/devices/system/cpu/cpu#/cpu_capacity +What: /sys/devices/system/cpu/aarch32_el0 +Date: May 2021 +Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> +Description: Identifies the subset of CPUs in the system that can execute + AArch32 (32-bit ARM) applications. If present, the same format as + /sys/devices/system/cpu/{offline,online,possible,present} is used. + If absent, then all or none of the CPUs can execute AArch32 + applications and execve() will behave accordingly. + +What: /sys/devices/system/cpu/cpuX/cpu_capacity Date: December 2016 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> Description: information about CPUs heterogeneity. - cpu_capacity: capacity of cpu#. + cpu_capacity: capacity of cpuX. What: /sys/devices/system/cpu/vulnerabilities + /sys/devices/system/cpu/vulnerabilities/gather_data_sampling + /sys/devices/system/cpu/vulnerabilities/itlb_multihit + /sys/devices/system/cpu/vulnerabilities/l1tf + /sys/devices/system/cpu/vulnerabilities/mds /sys/devices/system/cpu/vulnerabilities/meltdown + /sys/devices/system/cpu/vulnerabilities/mmio_stale_data + /sys/devices/system/cpu/vulnerabilities/retbleed + /sys/devices/system/cpu/vulnerabilities/spec_store_bypass /sys/devices/system/cpu/vulnerabilities/spectre_v1 /sys/devices/system/cpu/vulnerabilities/spectre_v2 - /sys/devices/system/cpu/vulnerabilities/spec_store_bypass - /sys/devices/system/cpu/vulnerabilities/l1tf - /sys/devices/system/cpu/vulnerabilities/mds + /sys/devices/system/cpu/vulnerabilities/srbds /sys/devices/system/cpu/vulnerabilities/tsx_async_abort - /sys/devices/system/cpu/vulnerabilities/itlb_multihit Date: January 2018 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> Description: Information about CPU vulnerabilities @@ -496,9 +530,11 @@ Description: Information about CPU vulnerabilities vulnerabilities. The output of those files reflects the state of the CPUs in the system. Possible output values: + ================ ============================================== "Not affected" CPU is not affected by the vulnerability "Vulnerable" CPU is affected and no mitigation in effect "Mitigation: $M" CPU is affected and mitigation $M is in effect + ================ ============================================== See also: Documentation/admin-guide/hw-vuln/index.rst @@ -507,24 +543,27 @@ What: /sys/devices/system/cpu/smt /sys/devices/system/cpu/smt/control Date: June 2018 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> -Description: Control Symetric Multi Threading (SMT) +Description: Control Symmetric Multi Threading (SMT) active: Tells whether SMT is active (enabled and siblings online) control: Read/write interface to control SMT. Possible values: + ================ ========================================= "on" SMT is enabled "off" SMT is disabled + "<N>" SMT is enabled with N threads per core. "forceoff" SMT is force disabled. Cannot be changed. "notsupported" SMT is not supported by the CPU "notimplemented" SMT runtime toggling is not implemented for the architecture + ================ ========================================= If control status is "forceoff" or "notsupported" writes are rejected. -What: /sys/devices/system/cpu/cpu#/power/energy_perf_bias +What: /sys/devices/system/cpu/cpuX/power/energy_perf_bias Date: March 2019 Contact: linux-pm@vger.kernel.org Description: Intel Energy and Performance Bias Hint (EPB) @@ -574,3 +613,83 @@ Description: Secure Virtual Machine If 1, it means the system is using the Protected Execution Facility in POWER9 and newer processors. i.e., it is a Secure Virtual Machine. + +What: /sys/devices/system/cpu/cpuX/purr +Date: Apr 2005 +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> +Description: PURR ticks for this CPU since the system boot. + + The Processor Utilization Resources Register (PURR) is + a 64-bit counter which provides an estimate of the + resources used by the CPU thread. The contents of this + register increases monotonically. This sysfs interface + exposes the number of PURR ticks for cpuX. + +What: /sys/devices/system/cpu/cpuX/spurr +Date: Dec 2006 +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> +Description: SPURR ticks for this CPU since the system boot. + + The Scaled Processor Utilization Resources Register + (SPURR) is a 64-bit counter that provides a frequency + invariant estimate of the resources used by the CPU + thread. The contents of this register increases + monotonically. This sysfs interface exposes the number + of SPURR ticks for cpuX. + +What: /sys/devices/system/cpu/cpuX/idle_purr +Date: Apr 2020 +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> +Description: PURR ticks for cpuX when it was idle. + + This sysfs interface exposes the number of PURR ticks + for cpuX when it was idle. + +What: /sys/devices/system/cpu/cpuX/idle_spurr +Date: Apr 2020 +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> +Description: SPURR ticks for cpuX when it was idle. + + This sysfs interface exposes the number of SPURR ticks + for cpuX when it was idle. + +What: /sys/devices/system/cpu/cpuX/mte_tcf_preferred +Date: July 2021 +Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> +Description: Preferred MTE tag checking mode + + When a user program specifies more than one MTE tag checking + mode, this sysfs node is used to specify which mode should + be preferred when scheduling a task on that CPU. Possible + values: + + ================ ============================================== + "sync" Prefer synchronous mode + "asymm" Prefer asymmetric mode + "async" Prefer asynchronous mode + ================ ============================================== + + See also: Documentation/arch/arm64/memory-tagging-extension.rst + +What: /sys/devices/system/cpu/nohz_full +Date: Apr 2015 +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: + (RO) the list of CPUs that are in nohz_full mode. + These CPUs are set by boot parameter "nohz_full=". + +What: /sys/devices/system/cpu/isolated +Date: Apr 2015 +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: + (RO) the list of CPUs that are isolated and don't + participate in load balancing. These CPUs are set by + boot parameter "isolcpus=". + +What: /sys/devices/system/cpu/crash_hotplug +Date: Aug 2023 +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: + (RO) indicates whether or not the kernel directly supports + modifying the crash elfcorehdr for CPU hot un/plug and/or + on/offline changes. |