1What: /sys/devices/system/cpu/ 2Date: pre-git history 3Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 4Description: 5 A collection of both global and individual CPU attributes 6 7 Individual CPU attributes are contained in subdirectories 8 named by the kernel's logical CPU number, e.g.: 9 10 /sys/devices/system/cpu/cpu#/ 11 12What: /sys/devices/system/cpu/kernel_max 13 /sys/devices/system/cpu/offline 14 /sys/devices/system/cpu/online 15 /sys/devices/system/cpu/possible 16 /sys/devices/system/cpu/present 17Date: December 2008 18Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 19Description: CPU topology files that describe kernel limits related to 20 hotplug. Briefly: 21 22 kernel_max: the maximum cpu index allowed by the kernel 23 configuration. 24 25 offline: cpus that are not online because they have been 26 HOTPLUGGED off or exceed the limit of cpus allowed by the 27 kernel configuration (kernel_max above). 28 29 online: cpus that are online and being scheduled. 30 31 possible: cpus that have been allocated resources and can be 32 brought online if they are present. 33 34 present: cpus that have been identified as being present in 35 the system. 36 37 See Documentation/admin-guide/cputopology.rst for more information. 38 39 40What: /sys/devices/system/cpu/probe 41 /sys/devices/system/cpu/release 42Date: November 2009 43Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 44Description: Dynamic addition and removal of CPU's. This is not hotplug 45 removal, this is meant complete removal/addition of the CPU 46 from the system. 47 48 probe: writes to this file will dynamically add a CPU to the 49 system. Information written to the file to add CPU's is 50 architecture specific. 51 52 release: writes to this file dynamically remove a CPU from 53 the system. Information writtento the file to remove CPU's 54 is architecture specific. 55 56What: /sys/devices/system/cpu/cpu#/node 57Date: October 2009 58Contact: Linux memory management mailing list <linux-mm@kvack.org> 59Description: Discover NUMA node a CPU belongs to 60 61 When CONFIG_NUMA is enabled, a symbolic link that points 62 to the corresponding NUMA node directory. 63 64 For example, the following symlink is created for cpu42 65 in NUMA node 2: 66 67 /sys/devices/system/cpu/cpu42/node2 -> ../../node/node2 68 69 70What: /sys/devices/system/cpu/cpu#/topology/core_id 71 /sys/devices/system/cpu/cpu#/topology/core_siblings 72 /sys/devices/system/cpu/cpu#/topology/core_siblings_list 73 /sys/devices/system/cpu/cpu#/topology/physical_package_id 74 /sys/devices/system/cpu/cpu#/topology/thread_siblings 75 /sys/devices/system/cpu/cpu#/topology/thread_siblings_list 76Date: December 2008 77Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 78Description: CPU topology files that describe a logical CPU's relationship 79 to other cores and threads in the same physical package. 80 81 One cpu# directory is created per logical CPU in the system, 82 e.g. /sys/devices/system/cpu/cpu42/. 83 84 Briefly, the files above are: 85 86 core_id: the CPU core ID of cpu#. Typically it is the 87 hardware platform's identifier (rather than the kernel's). 88 The actual value is architecture and platform dependent. 89 90 core_siblings: internal kernel map of cpu#'s hardware threads 91 within the same physical_package_id. 92 93 core_siblings_list: human-readable list of the logical CPU 94 numbers within the same physical_package_id as cpu#. 95 96 physical_package_id: physical package id of cpu#. Typically 97 corresponds to a physical socket number, but the actual value 98 is architecture and platform dependent. 99 100 thread_siblings: internel kernel map of cpu#'s hardware 101 threads within the same core as cpu# 102 103 thread_siblings_list: human-readable list of cpu#'s hardware 104 threads within the same core as cpu# 105 106 See Documentation/admin-guide/cputopology.rst for more information. 107 108 109What: /sys/devices/system/cpu/cpuidle/available_governors 110 /sys/devices/system/cpu/cpuidle/current_driver 111 /sys/devices/system/cpu/cpuidle/current_governor 112 /sys/devices/system/cpu/cpuidle/current_governer_ro 113Date: September 2007 114Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 115Description: Discover cpuidle policy and mechanism 116 117 Various CPUs today support multiple idle levels that are 118 differentiated by varying exit latencies and power 119 consumption during idle. 120 121 Idle policy (governor) is differentiated from idle mechanism 122 (driver). 123 124 available_governors: (RO) displays a space separated list of 125 available governors. 126 127 current_driver: (RO) displays current idle mechanism. 128 129 current_governor: (RW) displays current idle policy. Users can 130 switch the governor at runtime by writing to this file. 131 132 current_governor_ro: (RO) displays current idle policy. 133 134 See Documentation/admin-guide/pm/cpuidle.rst and 135 Documentation/driver-api/pm/cpuidle.rst for more information. 136 137 138What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/name 139 /sys/devices/system/cpu/cpuX/cpuidle/stateN/latency 140 /sys/devices/system/cpu/cpuX/cpuidle/stateN/power 141 /sys/devices/system/cpu/cpuX/cpuidle/stateN/time 142 /sys/devices/system/cpu/cpuX/cpuidle/stateN/usage 143 /sys/devices/system/cpu/cpuX/cpuidle/stateN/above 144 /sys/devices/system/cpu/cpuX/cpuidle/stateN/below 145Date: September 2007 146KernelVersion: v2.6.24 147Contact: Linux power management list <linux-pm@vger.kernel.org> 148Description: 149 The directory /sys/devices/system/cpu/cpuX/cpuidle contains per 150 logical CPU specific cpuidle information for each online cpu X. 151 The processor idle states which are available for use have the 152 following attributes: 153 154 name: (RO) Name of the idle state (string). 155 156 latency: (RO) The latency to exit out of this idle state (in 157 microseconds). 158 159 power: (RO) The power consumed while in this idle state (in 160 milliwatts). 161 162 time: (RO) The total time spent in this idle state (in microseconds). 163 164 usage: (RO) Number of times this state was entered (a count). 165 166 above: (RO) Number of times this state was entered, but the 167 observed CPU idle duration was too short for it (a count). 168 169 below: (RO) Number of times this state was entered, but the 170 observed CPU idle duration was too long for it (a count). 171 172What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/desc 173Date: February 2008 174KernelVersion: v2.6.25 175Contact: Linux power management list <linux-pm@vger.kernel.org> 176Description: 177 (RO) A small description about the idle state (string). 178 179 180What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/disable 181Date: March 2012 182KernelVersion: v3.10 183Contact: Linux power management list <linux-pm@vger.kernel.org> 184Description: 185 (RW) Option to disable this idle state (bool). The behavior and 186 the effect of the disable variable depends on the implementation 187 of a particular governor. In the ladder governor, for example, 188 it is not coherent, i.e. if one is disabling a light state, then 189 all deeper states are disabled as well, but the disable variable 190 does not reflect it. Likewise, if one enables a deep state but a 191 lighter state still is disabled, then this has no effect. 192 193What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/default_status 194Date: December 2019 195KernelVersion: v5.6 196Contact: Linux power management list <linux-pm@vger.kernel.org> 197Description: 198 (RO) The default status of this state, "enabled" or "disabled". 199 200What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency 201Date: March 2014 202KernelVersion: v3.15 203Contact: Linux power management list <linux-pm@vger.kernel.org> 204Description: 205 (RO) Display the target residency i.e. the minimum amount of 206 time (in microseconds) this cpu should spend in this idle state 207 to make the transition worth the effort. 208 209What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/ 210Date: March 2018 211KernelVersion: v4.17 212Contact: Linux power management list <linux-pm@vger.kernel.org> 213Description: 214 Idle state usage statistics related to suspend-to-idle. 215 216 This attribute group is only present for states that can be 217 used in suspend-to-idle with suspended timekeeping. 218 219What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/time 220Date: March 2018 221KernelVersion: v4.17 222Contact: Linux power management list <linux-pm@vger.kernel.org> 223Description: 224 Total time spent by the CPU in suspend-to-idle (with scheduler 225 tick suspended) after requesting this state. 226 227What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/usage 228Date: March 2018 229KernelVersion: v4.17 230Contact: Linux power management list <linux-pm@vger.kernel.org> 231Description: 232 Total number of times this state has been requested by the CPU 233 while entering suspend-to-idle. 234 235What: /sys/devices/system/cpu/cpu#/cpufreq/* 236Date: pre-git history 237Contact: linux-pm@vger.kernel.org 238Description: Discover and change clock speed of CPUs 239 240 Clock scaling allows you to change the clock speed of the 241 CPUs on the fly. This is a nice method to save battery 242 power, because the lower the clock speed, the less power 243 the CPU consumes. 244 245 There are many knobs to tweak in this directory. 246 247 See files in Documentation/cpu-freq/ for more information. 248 249 250What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus 251Date: June 2013 252Contact: linux-pm@vger.kernel.org 253Description: Discover CPUs in the same CPU frequency coordination domain 254 255 freqdomain_cpus is the list of CPUs (online+offline) that share 256 the same clock/freq domain (possibly at the hardware level). 257 That information may be hidden from the cpufreq core and the 258 value of related_cpus may be different from freqdomain_cpus. This 259 attribute is useful for user space DVFS controllers to get better 260 power/performance results for platforms using acpi-cpufreq. 261 262 This file is only present if the acpi-cpufreq driver is in use. 263 264 265What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1} 266Date: August 2008 267KernelVersion: 2.6.27 268Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 269Description: Disable L3 cache indices 270 271 These files exist in every CPU's cache/index3 directory. Each 272 cache_disable_{0,1} file corresponds to one disable slot which 273 can be used to disable a cache index. Reading from these files 274 on a processor with this functionality will return the currently 275 disabled index for that node. There is one L3 structure per 276 node, or per internal node on MCM machines. Writing a valid 277 index to one of these files will cause the specificed cache 278 index to be disabled. 279 280 All AMD processors with L3 caches provide this functionality. 281 For details, see BKDGs at 282 http://developer.amd.com/documentation/guides/Pages/default.aspx 283 284 285What: /sys/devices/system/cpu/cpufreq/boost 286Date: August 2012 287Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 288Description: Processor frequency boosting control 289 290 This switch controls the boost setting for the whole system. 291 Boosting allows the CPU and the firmware to run at a frequency 292 beyound it's nominal limit. 293 More details can be found in 294 Documentation/admin-guide/pm/cpufreq.rst 295 296 297What: /sys/devices/system/cpu/cpu#/crash_notes 298 /sys/devices/system/cpu/cpu#/crash_notes_size 299Date: April 2013 300Contact: kexec@lists.infradead.org 301Description: address and size of the percpu note. 302 303 crash_notes: the physical address of the memory that holds the 304 note of cpu#. 305 306 crash_notes_size: size of the note of cpu#. 307 308 309What: /sys/devices/system/cpu/intel_pstate/max_perf_pct 310 /sys/devices/system/cpu/intel_pstate/min_perf_pct 311 /sys/devices/system/cpu/intel_pstate/no_turbo 312Date: February 2013 313Contact: linux-pm@vger.kernel.org 314Description: Parameters for the Intel P-state driver 315 316 Logic for selecting the current P-state in Intel 317 Sandybridge+ processors. The three knobs control 318 limits for the P-state that will be requested by the 319 driver. 320 321 max_perf_pct: limits the maximum P state that will be requested by 322 the driver stated as a percentage of the available performance. 323 324 min_perf_pct: limits the minimum P state that will be requested by 325 the driver stated as a percentage of the available performance. 326 327 no_turbo: limits the driver to selecting P states below the turbo 328 frequency range. 329 330 More details can be found in 331 Documentation/admin-guide/pm/intel_pstate.rst 332 333What: /sys/devices/system/cpu/cpu*/cache/index*/<set_of_attributes_mentioned_below> 334Date: July 2014(documented, existed before August 2008) 335Contact: Sudeep Holla <sudeep.holla@arm.com> 336 Linux kernel mailing list <linux-kernel@vger.kernel.org> 337Description: Parameters for the CPU cache attributes 338 339 allocation_policy: 340 - WriteAllocate: allocate a memory location to a cache line 341 on a cache miss because of a write 342 - ReadAllocate: allocate a memory location to a cache line 343 on a cache miss because of a read 344 - ReadWriteAllocate: both writeallocate and readallocate 345 346 attributes: LEGACY used only on IA64 and is same as write_policy 347 348 coherency_line_size: the minimum amount of data in bytes that gets 349 transferred from memory to cache 350 351 level: the cache hierarchy in the multi-level cache configuration 352 353 number_of_sets: total number of sets in the cache, a set is a 354 collection of cache lines with the same cache index 355 356 physical_line_partition: number of physical cache line per cache tag 357 358 shared_cpu_list: the list of logical cpus sharing the cache 359 360 shared_cpu_map: logical cpu mask containing the list of cpus sharing 361 the cache 362 363 size: the total cache size in kB 364 365 type: 366 - Instruction: cache that only holds instructions 367 - Data: cache that only caches data 368 - Unified: cache that holds both data and instructions 369 370 ways_of_associativity: degree of freedom in placing a particular block 371 of memory in the cache 372 373 write_policy: 374 - WriteThrough: data is written to both the cache line 375 and to the block in the lower-level memory 376 - WriteBack: data is written only to the cache line and 377 the modified cache line is written to main 378 memory only when it is replaced 379 380 381What: /sys/devices/system/cpu/cpu*/cache/index*/id 382Date: September 2016 383Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 384Description: Cache id 385 386 The id provides a unique number for a specific instance of 387 a cache of a particular type. E.g. there may be a level 388 3 unified cache on each socket in a server and we may 389 assign them ids 0, 1, 2, ... 390 391 Note that id value can be non-contiguous. E.g. level 1 392 caches typically exist per core, but there may not be a 393 power of two cores on a socket, so these caches may be 394 numbered 0, 1, 2, 3, 4, 5, 8, 9, 10, ... 395 396What: /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats 397 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat 398 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub_turbo_stat 399 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle 400 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap 401 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp 402 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault 403 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent 404 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset 405Date: March 2016 406Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 407 Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 408Description: POWERNV CPUFreq driver's frequency throttle stats directory and 409 attributes 410 411 'cpuX/cpufreq/throttle_stats' directory contains the CPU frequency 412 throttle stat attributes for the chip. The throttle stats of a cpu 413 is common across all the cpus belonging to a chip. Below are the 414 throttle attributes exported in the 'throttle_stats' directory: 415 416 - turbo_stat : This file gives the total number of times the max 417 frequency is throttled to lower frequency in turbo (at and above 418 nominal frequency) range of frequencies. 419 420 - sub_turbo_stat : This file gives the total number of times the 421 max frequency is throttled to lower frequency in sub-turbo(below 422 nominal frequency) range of frequencies. 423 424 - unthrottle : This file gives the total number of times the max 425 frequency is unthrottled after being throttled. 426 427 - powercap : This file gives the total number of times the max 428 frequency is throttled due to 'Power Capping'. 429 430 - overtemp : This file gives the total number of times the max 431 frequency is throttled due to 'CPU Over Temperature'. 432 433 - supply_fault : This file gives the total number of times the 434 max frequency is throttled due to 'Power Supply Failure'. 435 436 - overcurrent : This file gives the total number of times the 437 max frequency is throttled due to 'Overcurrent'. 438 439 - occ_reset : This file gives the total number of times the max 440 frequency is throttled due to 'OCC Reset'. 441 442 The sysfs attributes representing different throttle reasons like 443 powercap, overtemp, supply_fault, overcurrent and occ_reset map to 444 the reasons provided by OCC firmware for throttling the frequency. 445 446What: /sys/devices/system/cpu/cpufreq/policyX/throttle_stats 447 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/turbo_stat 448 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/sub_turbo_stat 449 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/unthrottle 450 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/powercap 451 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overtemp 452 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/supply_fault 453 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overcurrent 454 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/occ_reset 455Date: March 2016 456Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 457 Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 458Description: POWERNV CPUFreq driver's frequency throttle stats directory and 459 attributes 460 461 'policyX/throttle_stats' directory and all the attributes are same as 462 the /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory and 463 attributes which give the frequency throttle information of the chip. 464 465What: /sys/devices/system/cpu/cpuX/regs/ 466 /sys/devices/system/cpu/cpuX/regs/identification/ 467 /sys/devices/system/cpu/cpuX/regs/identification/midr_el1 468 /sys/devices/system/cpu/cpuX/regs/identification/revidr_el1 469Date: June 2016 470Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> 471Description: AArch64 CPU registers 472 'identification' directory exposes the CPU ID registers for 473 identifying model and revision of the CPU. 474 475What: /sys/devices/system/cpu/cpu#/cpu_capacity 476Date: December 2016 477Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 478Description: information about CPUs heterogeneity. 479 480 cpu_capacity: capacity of cpu#. 481 482What: /sys/devices/system/cpu/vulnerabilities 483 /sys/devices/system/cpu/vulnerabilities/meltdown 484 /sys/devices/system/cpu/vulnerabilities/spectre_v1 485 /sys/devices/system/cpu/vulnerabilities/spectre_v2 486 /sys/devices/system/cpu/vulnerabilities/spec_store_bypass 487 /sys/devices/system/cpu/vulnerabilities/l1tf 488 /sys/devices/system/cpu/vulnerabilities/mds 489 /sys/devices/system/cpu/vulnerabilities/srbds 490 /sys/devices/system/cpu/vulnerabilities/tsx_async_abort 491 /sys/devices/system/cpu/vulnerabilities/itlb_multihit 492Date: January 2018 493Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 494Description: Information about CPU vulnerabilities 495 496 The files are named after the code names of CPU 497 vulnerabilities. The output of those files reflects the 498 state of the CPUs in the system. Possible output values: 499 500 "Not affected" CPU is not affected by the vulnerability 501 "Vulnerable" CPU is affected and no mitigation in effect 502 "Mitigation: $M" CPU is affected and mitigation $M is in effect 503 504 See also: Documentation/admin-guide/hw-vuln/index.rst 505 506What: /sys/devices/system/cpu/smt 507 /sys/devices/system/cpu/smt/active 508 /sys/devices/system/cpu/smt/control 509Date: June 2018 510Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 511Description: Control Symetric Multi Threading (SMT) 512 513 active: Tells whether SMT is active (enabled and siblings online) 514 515 control: Read/write interface to control SMT. Possible 516 values: 517 518 "on" SMT is enabled 519 "off" SMT is disabled 520 "forceoff" SMT is force disabled. Cannot be changed. 521 "notsupported" SMT is not supported by the CPU 522 "notimplemented" SMT runtime toggling is not 523 implemented for the architecture 524 525 If control status is "forceoff" or "notsupported" writes 526 are rejected. 527 528What: /sys/devices/system/cpu/cpu#/power/energy_perf_bias 529Date: March 2019 530Contact: linux-pm@vger.kernel.org 531Description: Intel Energy and Performance Bias Hint (EPB) 532 533 EPB for the given CPU in a sliding scale 0 - 15, where a value 534 of 0 corresponds to a hint preference for highest performance 535 and a value of 15 corresponds to the maximum energy savings. 536 537 In order to change the EPB value for the CPU, write either 538 a number in the 0 - 15 sliding scale above, or one of the 539 strings: "performance", "balance-performance", "normal", 540 "balance-power", "power" (that represent values reflected by 541 their meaning), to this attribute. 542 543 This attribute is present for all online CPUs supporting the 544 Intel EPB feature. 545 546What: /sys/devices/system/cpu/umwait_control 547 /sys/devices/system/cpu/umwait_control/enable_c02 548 /sys/devices/system/cpu/umwait_control/max_time 549Date: May 2019 550Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 551Description: Umwait control 552 553 enable_c02: Read/write interface to control umwait C0.2 state 554 Read returns C0.2 state status: 555 0: C0.2 is disabled 556 1: C0.2 is enabled 557 558 Write 'y' or '1' or 'on' to enable C0.2 state. 559 Write 'n' or '0' or 'off' to disable C0.2 state. 560 561 The interface is case insensitive. 562 563 max_time: Read/write interface to control umwait maximum time 564 in TSC-quanta that the CPU can reside in either C0.1 565 or C0.2 state. The time is an unsigned 32-bit number. 566 Note that a value of zero means there is no limit. 567 Low order two bits must be zero. 568 569What: /sys/devices/system/cpu/svm 570Date: August 2019 571Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 572 Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 573Description: Secure Virtual Machine 574 575 If 1, it means the system is using the Protected Execution 576 Facility in POWER9 and newer processors. i.e., it is a Secure 577 Virtual Machine. 578 579What: /sys/devices/system/cpu/cpuX/purr 580Date: Apr 2005 581Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 582Description: PURR ticks for this CPU since the system boot. 583 584 The Processor Utilization Resources Register (PURR) is 585 a 64-bit counter which provides an estimate of the 586 resources used by the CPU thread. The contents of this 587 register increases monotonically. This sysfs interface 588 exposes the number of PURR ticks for cpuX. 589 590What: /sys/devices/system/cpu/cpuX/spurr 591Date: Dec 2006 592Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 593Description: SPURR ticks for this CPU since the system boot. 594 595 The Scaled Processor Utilization Resources Register 596 (SPURR) is a 64-bit counter that provides a frequency 597 invariant estimate of the resources used by the CPU 598 thread. The contents of this register increases 599 monotonically. This sysfs interface exposes the number 600 of SPURR ticks for cpuX. 601 602What: /sys/devices/system/cpu/cpuX/idle_purr 603Date: Apr 2020 604Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 605Description: PURR ticks for cpuX when it was idle. 606 607 This sysfs interface exposes the number of PURR ticks 608 for cpuX when it was idle. 609 610What: /sys/devices/system/cpu/cpuX/idle_spurr 611Date: Apr 2020 612Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 613Description: SPURR ticks for cpuX when it was idle. 614 615 This sysfs interface exposes the number of SPURR ticks 616 for cpuX when it was idle. 617