diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-system-cpu')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 296 |
1 files changed, 201 insertions, 95 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 2e0e3b45d02a..f54867cadb0f 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> @@ -196,14 +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/stateN/default_status +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> @@ -212,7 +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> @@ -222,7 +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> @@ -230,7 +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> @@ -238,7 +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 @@ -253,7 +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 @@ -265,7 +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} @@ -280,12 +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 @@ -295,21 +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 @@ -343,43 +345,57 @@ 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 + 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 @@ -420,30 +436,30 @@ 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 @@ -472,18 +488,29 @@ 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/meltdown @@ -492,8 +519,11 @@ What: /sys/devices/system/cpu/vulnerabilities /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 + /sys/devices/system/cpu/vulnerabilities/mmio_stale_data + /sys/devices/system/cpu/vulnerabilities/retbleed Date: January 2018 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> Description: Information about CPU vulnerabilities @@ -502,9 +532,11 @@ 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 @@ -513,24 +545,26 @@ 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 "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) @@ -580,3 +614,75 @@ 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/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=". |