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 ======== ==== ================================================= 155 name: (RO) Name of the idle state (string). 156 157 latency: (RO) The latency to exit out of this idle state (in 158 microseconds). 159 160 power: (RO) The power consumed while in this idle state (in 161 milliwatts). 162 163 time: (RO) The total time spent in this idle state 164 (in microseconds). 165 166 usage: (RO) Number of times this state was entered (a count). 167 168 above: (RO) Number of times this state was entered, but the 169 observed CPU idle duration was too short for it 170 (a count). 171 172 below: (RO) Number of times this state was entered, but the 173 observed CPU idle duration was too long for it 174 (a count). 175 ======== ==== ================================================= 176 177What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/desc 178Date: February 2008 179KernelVersion: v2.6.25 180Contact: Linux power management list <linux-pm@vger.kernel.org> 181Description: 182 (RO) A small description about the idle state (string). 183 184 185What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/disable 186Date: March 2012 187KernelVersion: v3.10 188Contact: Linux power management list <linux-pm@vger.kernel.org> 189Description: 190 (RW) Option to disable this idle state (bool). The behavior and 191 the effect of the disable variable depends on the implementation 192 of a particular governor. In the ladder governor, for example, 193 it is not coherent, i.e. if one is disabling a light state, then 194 all deeper states are disabled as well, but the disable variable 195 does not reflect it. Likewise, if one enables a deep state but a 196 lighter state still is disabled, then this has no effect. 197 198What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/default_status 199Date: December 2019 200KernelVersion: v5.6 201Contact: Linux power management list <linux-pm@vger.kernel.org> 202Description: 203 (RO) The default status of this state, "enabled" or "disabled". 204 205What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency 206Date: March 2014 207KernelVersion: v3.15 208Contact: Linux power management list <linux-pm@vger.kernel.org> 209Description: 210 (RO) Display the target residency i.e. the minimum amount of 211 time (in microseconds) this cpu should spend in this idle state 212 to make the transition worth the effort. 213 214What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/ 215Date: March 2018 216KernelVersion: v4.17 217Contact: Linux power management list <linux-pm@vger.kernel.org> 218Description: 219 Idle state usage statistics related to suspend-to-idle. 220 221 This attribute group is only present for states that can be 222 used in suspend-to-idle with suspended timekeeping. 223 224What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/time 225Date: March 2018 226KernelVersion: v4.17 227Contact: Linux power management list <linux-pm@vger.kernel.org> 228Description: 229 Total time spent by the CPU in suspend-to-idle (with scheduler 230 tick suspended) after requesting this state. 231 232What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/usage 233Date: March 2018 234KernelVersion: v4.17 235Contact: Linux power management list <linux-pm@vger.kernel.org> 236Description: 237 Total number of times this state has been requested by the CPU 238 while entering suspend-to-idle. 239 240What: /sys/devices/system/cpu/cpu#/cpufreq/* 241Date: pre-git history 242Contact: linux-pm@vger.kernel.org 243Description: Discover and change clock speed of CPUs 244 245 Clock scaling allows you to change the clock speed of the 246 CPUs on the fly. This is a nice method to save battery 247 power, because the lower the clock speed, the less power 248 the CPU consumes. 249 250 There are many knobs to tweak in this directory. 251 252 See files in Documentation/cpu-freq/ for more information. 253 254 255What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus 256Date: June 2013 257Contact: linux-pm@vger.kernel.org 258Description: Discover CPUs in the same CPU frequency coordination domain 259 260 freqdomain_cpus is the list of CPUs (online+offline) that share 261 the same clock/freq domain (possibly at the hardware level). 262 That information may be hidden from the cpufreq core and the 263 value of related_cpus may be different from freqdomain_cpus. This 264 attribute is useful for user space DVFS controllers to get better 265 power/performance results for platforms using acpi-cpufreq. 266 267 This file is only present if the acpi-cpufreq driver is in use. 268 269 270What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1} 271Date: August 2008 272KernelVersion: 2.6.27 273Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 274Description: Disable L3 cache indices 275 276 These files exist in every CPU's cache/index3 directory. Each 277 cache_disable_{0,1} file corresponds to one disable slot which 278 can be used to disable a cache index. Reading from these files 279 on a processor with this functionality will return the currently 280 disabled index for that node. There is one L3 structure per 281 node, or per internal node on MCM machines. Writing a valid 282 index to one of these files will cause the specificed cache 283 index to be disabled. 284 285 All AMD processors with L3 caches provide this functionality. 286 For details, see BKDGs at 287 http://developer.amd.com/documentation/guides/Pages/default.aspx 288 289 290What: /sys/devices/system/cpu/cpufreq/boost 291Date: August 2012 292Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 293Description: Processor frequency boosting control 294 295 This switch controls the boost setting for the whole system. 296 Boosting allows the CPU and the firmware to run at a frequency 297 beyound it's nominal limit. 298 299 More details can be found in 300 Documentation/admin-guide/pm/cpufreq.rst 301 302 303What: /sys/devices/system/cpu/cpu#/crash_notes 304 /sys/devices/system/cpu/cpu#/crash_notes_size 305Date: April 2013 306Contact: kexec@lists.infradead.org 307Description: address and size of the percpu note. 308 309 crash_notes: the physical address of the memory that holds the 310 note of cpu#. 311 312 crash_notes_size: size of the note of cpu#. 313 314 315What: /sys/devices/system/cpu/intel_pstate/max_perf_pct 316 /sys/devices/system/cpu/intel_pstate/min_perf_pct 317 /sys/devices/system/cpu/intel_pstate/no_turbo 318Date: February 2013 319Contact: linux-pm@vger.kernel.org 320Description: Parameters for the Intel P-state driver 321 322 Logic for selecting the current P-state in Intel 323 Sandybridge+ processors. The three knobs control 324 limits for the P-state that will be requested by the 325 driver. 326 327 max_perf_pct: limits the maximum P state that will be requested by 328 the driver stated as a percentage of the available performance. 329 330 min_perf_pct: limits the minimum P state that will be requested by 331 the driver stated as a percentage of the available performance. 332 333 no_turbo: limits the driver to selecting P states below the turbo 334 frequency range. 335 336 More details can be found in 337 Documentation/admin-guide/pm/intel_pstate.rst 338 339What: /sys/devices/system/cpu/cpu*/cache/index*/<set_of_attributes_mentioned_below> 340Date: July 2014(documented, existed before August 2008) 341Contact: Sudeep Holla <sudeep.holla@arm.com> 342 Linux kernel mailing list <linux-kernel@vger.kernel.org> 343Description: Parameters for the CPU cache attributes 344 345 allocation_policy: 346 - WriteAllocate: 347 allocate a memory location to a cache line 348 on a cache miss because of a write 349 - ReadAllocate: 350 allocate a memory location to a cache line 351 on a cache miss because of a read 352 - ReadWriteAllocate: 353 both writeallocate and readallocate 354 355 attributes: 356 LEGACY used only on IA64 and is same as write_policy 357 358 coherency_line_size: 359 the minimum amount of data in bytes that gets 360 transferred from memory to cache 361 362 level: 363 the cache hierarchy in the multi-level cache configuration 364 365 number_of_sets: 366 total number of sets in the cache, a set is a 367 collection of cache lines with the same cache index 368 369 physical_line_partition: 370 number of physical cache line per cache tag 371 372 shared_cpu_list: 373 the list of logical cpus sharing the cache 374 375 shared_cpu_map: 376 logical cpu mask containing the list of cpus sharing 377 the cache 378 379 size: 380 the total cache size in kB 381 382 type: 383 - Instruction: cache that only holds instructions 384 - Data: cache that only caches data 385 - Unified: cache that holds both data and instructions 386 387 ways_of_associativity: 388 degree of freedom in placing a particular block 389 of memory in the cache 390 391 write_policy: 392 - WriteThrough: 393 data is written to both the cache line 394 and to the block in the lower-level memory 395 - WriteBack: 396 data is written only to the cache line and 397 the modified cache line is written to main 398 memory only when it is replaced 399 400 401What: /sys/devices/system/cpu/cpu*/cache/index*/id 402Date: September 2016 403Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 404Description: Cache id 405 406 The id provides a unique number for a specific instance of 407 a cache of a particular type. E.g. there may be a level 408 3 unified cache on each socket in a server and we may 409 assign them ids 0, 1, 2, ... 410 411 Note that id value can be non-contiguous. E.g. level 1 412 caches typically exist per core, but there may not be a 413 power of two cores on a socket, so these caches may be 414 numbered 0, 1, 2, 3, 4, 5, 8, 9, 10, ... 415 416What: /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats 417 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat 418 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub_turbo_stat 419 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle 420 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap 421 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp 422 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault 423 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent 424 /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset 425Date: March 2016 426Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 427 Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 428Description: POWERNV CPUFreq driver's frequency throttle stats directory and 429 attributes 430 431 'cpuX/cpufreq/throttle_stats' directory contains the CPU frequency 432 throttle stat attributes for the chip. The throttle stats of a cpu 433 is common across all the cpus belonging to a chip. Below are the 434 throttle attributes exported in the 'throttle_stats' directory: 435 436 - turbo_stat : This file gives the total number of times the max 437 frequency is throttled to lower frequency in turbo (at and above 438 nominal frequency) range of frequencies. 439 440 - sub_turbo_stat : This file gives the total number of times the 441 max frequency is throttled to lower frequency in sub-turbo(below 442 nominal frequency) range of frequencies. 443 444 - unthrottle : This file gives the total number of times the max 445 frequency is unthrottled after being throttled. 446 447 - powercap : This file gives the total number of times the max 448 frequency is throttled due to 'Power Capping'. 449 450 - overtemp : This file gives the total number of times the max 451 frequency is throttled due to 'CPU Over Temperature'. 452 453 - supply_fault : This file gives the total number of times the 454 max frequency is throttled due to 'Power Supply Failure'. 455 456 - overcurrent : This file gives the total number of times the 457 max frequency is throttled due to 'Overcurrent'. 458 459 - occ_reset : This file gives the total number of times the max 460 frequency is throttled due to 'OCC Reset'. 461 462 The sysfs attributes representing different throttle reasons like 463 powercap, overtemp, supply_fault, overcurrent and occ_reset map to 464 the reasons provided by OCC firmware for throttling the frequency. 465 466What: /sys/devices/system/cpu/cpufreq/policyX/throttle_stats 467 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/turbo_stat 468 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/sub_turbo_stat 469 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/unthrottle 470 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/powercap 471 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overtemp 472 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/supply_fault 473 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overcurrent 474 /sys/devices/system/cpu/cpufreq/policyX/throttle_stats/occ_reset 475Date: March 2016 476Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 477 Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 478Description: POWERNV CPUFreq driver's frequency throttle stats directory and 479 attributes 480 481 'policyX/throttle_stats' directory and all the attributes are same as 482 the /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory and 483 attributes which give the frequency throttle information of the chip. 484 485What: /sys/devices/system/cpu/cpuX/regs/ 486 /sys/devices/system/cpu/cpuX/regs/identification/ 487 /sys/devices/system/cpu/cpuX/regs/identification/midr_el1 488 /sys/devices/system/cpu/cpuX/regs/identification/revidr_el1 489Date: June 2016 490Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> 491Description: AArch64 CPU registers 492 493 'identification' directory exposes the CPU ID registers for 494 identifying model and revision of the CPU. 495 496What: /sys/devices/system/cpu/cpu#/cpu_capacity 497Date: December 2016 498Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 499Description: information about CPUs heterogeneity. 500 501 cpu_capacity: capacity of cpu#. 502 503What: /sys/devices/system/cpu/vulnerabilities 504 /sys/devices/system/cpu/vulnerabilities/meltdown 505 /sys/devices/system/cpu/vulnerabilities/spectre_v1 506 /sys/devices/system/cpu/vulnerabilities/spectre_v2 507 /sys/devices/system/cpu/vulnerabilities/spec_store_bypass 508 /sys/devices/system/cpu/vulnerabilities/l1tf 509 /sys/devices/system/cpu/vulnerabilities/mds 510 /sys/devices/system/cpu/vulnerabilities/srbds 511 /sys/devices/system/cpu/vulnerabilities/tsx_async_abort 512 /sys/devices/system/cpu/vulnerabilities/itlb_multihit 513Date: January 2018 514Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 515Description: Information about CPU vulnerabilities 516 517 The files are named after the code names of CPU 518 vulnerabilities. The output of those files reflects the 519 state of the CPUs in the system. Possible output values: 520 521 ================ ============================================== 522 "Not affected" CPU is not affected by the vulnerability 523 "Vulnerable" CPU is affected and no mitigation in effect 524 "Mitigation: $M" CPU is affected and mitigation $M is in effect 525 ================ ============================================== 526 527 See also: Documentation/admin-guide/hw-vuln/index.rst 528 529What: /sys/devices/system/cpu/smt 530 /sys/devices/system/cpu/smt/active 531 /sys/devices/system/cpu/smt/control 532Date: June 2018 533Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 534Description: Control Symetric Multi Threading (SMT) 535 536 active: Tells whether SMT is active (enabled and siblings online) 537 538 control: Read/write interface to control SMT. Possible 539 values: 540 541 ================ ========================================= 542 "on" SMT is enabled 543 "off" SMT is disabled 544 "forceoff" SMT is force disabled. Cannot be changed. 545 "notsupported" SMT is not supported by the CPU 546 "notimplemented" SMT runtime toggling is not 547 implemented for the architecture 548 ================ ========================================= 549 550 If control status is "forceoff" or "notsupported" writes 551 are rejected. 552 553What: /sys/devices/system/cpu/cpu#/power/energy_perf_bias 554Date: March 2019 555Contact: linux-pm@vger.kernel.org 556Description: Intel Energy and Performance Bias Hint (EPB) 557 558 EPB for the given CPU in a sliding scale 0 - 15, where a value 559 of 0 corresponds to a hint preference for highest performance 560 and a value of 15 corresponds to the maximum energy savings. 561 562 In order to change the EPB value for the CPU, write either 563 a number in the 0 - 15 sliding scale above, or one of the 564 strings: "performance", "balance-performance", "normal", 565 "balance-power", "power" (that represent values reflected by 566 their meaning), to this attribute. 567 568 This attribute is present for all online CPUs supporting the 569 Intel EPB feature. 570 571What: /sys/devices/system/cpu/umwait_control 572 /sys/devices/system/cpu/umwait_control/enable_c02 573 /sys/devices/system/cpu/umwait_control/max_time 574Date: May 2019 575Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 576Description: Umwait control 577 578 enable_c02: Read/write interface to control umwait C0.2 state 579 Read returns C0.2 state status: 580 0: C0.2 is disabled 581 1: C0.2 is enabled 582 583 Write 'y' or '1' or 'on' to enable C0.2 state. 584 Write 'n' or '0' or 'off' to disable C0.2 state. 585 586 The interface is case insensitive. 587 588 max_time: Read/write interface to control umwait maximum time 589 in TSC-quanta that the CPU can reside in either C0.1 590 or C0.2 state. The time is an unsigned 32-bit number. 591 Note that a value of zero means there is no limit. 592 Low order two bits must be zero. 593 594What: /sys/devices/system/cpu/svm 595Date: August 2019 596Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> 597 Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 598Description: Secure Virtual Machine 599 600 If 1, it means the system is using the Protected Execution 601 Facility in POWER9 and newer processors. i.e., it is a Secure 602 Virtual Machine. 603 604What: /sys/devices/system/cpu/cpuX/purr 605Date: Apr 2005 606Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 607Description: PURR ticks for this CPU since the system boot. 608 609 The Processor Utilization Resources Register (PURR) is 610 a 64-bit counter which provides an estimate of the 611 resources used by the CPU thread. The contents of this 612 register increases monotonically. This sysfs interface 613 exposes the number of PURR ticks for cpuX. 614 615What: /sys/devices/system/cpu/cpuX/spurr 616Date: Dec 2006 617Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 618Description: SPURR ticks for this CPU since the system boot. 619 620 The Scaled Processor Utilization Resources Register 621 (SPURR) is a 64-bit counter that provides a frequency 622 invariant estimate of the resources used by the CPU 623 thread. The contents of this register increases 624 monotonically. This sysfs interface exposes the number 625 of SPURR ticks for cpuX. 626 627What: /sys/devices/system/cpu/cpuX/idle_purr 628Date: Apr 2020 629Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 630Description: PURR ticks for cpuX when it was idle. 631 632 This sysfs interface exposes the number of PURR ticks 633 for cpuX when it was idle. 634 635What: /sys/devices/system/cpu/cpuX/idle_spurr 636Date: Apr 2020 637Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org> 638Description: SPURR ticks for cpuX when it was idle. 639 640 This sysfs interface exposes the number of SPURR ticks 641 for cpuX when it was idle. 642