1ec8f24b7SThomas Gleixner# SPDX-License-Identifier: GPL-2.0-only 2296699deSRafael J. Wysockiconfig SUSPEND 3296699deSRafael J. Wysocki bool "Suspend to RAM and standby" 41eb208aeSRafael J. Wysocki depends on ARCH_SUSPEND_POSSIBLE 5296699deSRafael J. Wysocki default y 6a7f7f624SMasahiro Yamada help 7296699deSRafael J. Wysocki Allow the system to enter sleep states in which main memory is 8296699deSRafael J. Wysocki powered and thus its contents are preserved, such as the 9f4cb5700SJohannes Berg suspend-to-RAM state (e.g. the ACPI S3 state). 10296699deSRafael J. Wysocki 11b28f5081SJohannes Bergconfig SUSPEND_FREEZER 12b28f5081SJohannes Berg bool "Enable freezer for suspend to RAM/standby" \ 13b28f5081SJohannes Berg if ARCH_WANTS_FREEZER_CONTROL || BROKEN 14b28f5081SJohannes Berg depends on SUSPEND 15b28f5081SJohannes Berg default y 16b28f5081SJohannes Berg help 17b28f5081SJohannes Berg This allows you to turn off the freezer for suspend. If this is 18b28f5081SJohannes Berg done, no tasks are frozen for suspend to RAM/standby. 19b28f5081SJohannes Berg 20b28f5081SJohannes Berg Turning OFF this setting is NOT recommended! If in doubt, say Y. 21b28f5081SJohannes Berg 222fd77fffSLen Brownconfig SUSPEND_SKIP_SYNC 232fd77fffSLen Brown bool "Skip kernel's sys_sync() on suspend to RAM/standby" 242fd77fffSLen Brown depends on SUSPEND 252fd77fffSLen Brown depends on EXPERT 262fd77fffSLen Brown help 272fd77fffSLen Brown Skip the kernel sys_sync() before freezing user processes. 282fd77fffSLen Brown Some systems prefer not to pay this cost on every invocation 292fd77fffSLen Brown of suspend, or they are content with invoking sync() from 30c052bf82SJonas Meurer user-space before invoking suspend. There's a run-time switch 31c052bf82SJonas Meurer at '/sys/power/sync_on_suspend' to configure this behaviour. 32c052bf82SJonas Meurer This setting changes the default for the run-tim switch. Say Y 33c052bf82SJonas Meurer to change the default to disable the kernel sys_sync(). 342fd77fffSLen Brown 351f112ceeSRafael J. Wysockiconfig HIBERNATE_CALLBACKS 361f112ceeSRafael J. Wysocki bool 371f112ceeSRafael J. Wysocki 38b0cb1a19SRafael J. Wysockiconfig HIBERNATION 39296699deSRafael J. Wysocki bool "Hibernation (aka 'suspend to disk')" 401eb208aeSRafael J. Wysocki depends on SWAP && ARCH_HIBERNATION_POSSIBLE 411f112ceeSRafael J. Wysocki select HIBERNATE_CALLBACKS 42081a9d04SBojan Smojver select CRC32 43a06c6f5dSNikhil V select CRYPTO 44a06c6f5dSNikhil V select CRYPTO_LZO 45a7f7f624SMasahiro Yamada help 46a7ee2e5fSDavid Brownell Enable the suspend to disk (STD) functionality, which is usually 47a7ee2e5fSDavid Brownell called "hibernation" in user interfaces. STD checkpoints the 48a7ee2e5fSDavid Brownell system and powers it off; and restores that checkpoint on reboot. 491da177e4SLinus Torvalds 5023b168d4SPavel Machek You can suspend your machine with 'echo disk > /sys/power/state' 5123b168d4SPavel Machek after placing resume=/dev/swappartition on the kernel command line 5223b168d4SPavel Machek in your bootloader's configuration file. 5323b168d4SPavel Machek 54c7276fdeSRafael J. Wysocki Alternatively, you can use the additional userland tools available 55c7276fdeSRafael J. Wysocki from <http://suspend.sf.net>. 56c7276fdeSRafael J. Wysocki 57c7276fdeSRafael J. Wysocki In principle it does not require ACPI or APM, although for example 58a7ee2e5fSDavid Brownell ACPI will be used for the final steps when it is available. One 59a7ee2e5fSDavid Brownell of the reasons to use software suspend is that the firmware hooks 60a7ee2e5fSDavid Brownell for suspend states like suspend-to-RAM (STR) often don't work very 61a7ee2e5fSDavid Brownell well with Linux. 62c7276fdeSRafael J. Wysocki 63c7276fdeSRafael J. Wysocki It creates an image which is saved in your active swap. Upon the next 641da177e4SLinus Torvalds boot, pass the 'resume=/dev/swappartition' argument to the kernel to 651da177e4SLinus Torvalds have it detect the saved image, restore memory state from it, and 661da177e4SLinus Torvalds continue to run as before. If you do not want the previous state to 67c7276fdeSRafael J. Wysocki be reloaded, then use the 'noresume' kernel command line argument. 68c7276fdeSRafael J. Wysocki Note, however, that fsck will be run on your filesystems and you will 69c7276fdeSRafael J. Wysocki need to run mkswap against the swap partition used for the suspend. 701da177e4SLinus Torvalds 71c7276fdeSRafael J. Wysocki It also works with swap files to a limited extent (for details see 72151f4e2bSMauro Carvalho Chehab <file:Documentation/power/swsusp-and-swap-files.rst>). 73c7276fdeSRafael J. Wysocki 74c7276fdeSRafael J. Wysocki Right now you may boot without resuming and resume later but in the 75c7276fdeSRafael J. Wysocki meantime you cannot use the swap partition(s)/file(s) involved in 76c7276fdeSRafael J. Wysocki suspending. Also in this case you must not use the filesystems 77c7276fdeSRafael J. Wysocki that were mounted before the suspend. In particular, you MUST NOT 78c7276fdeSRafael J. Wysocki MOUNT any journaled filesystems mounted before the suspend or they 79c7276fdeSRafael J. Wysocki will get corrupted in a nasty way. 801da177e4SLinus Torvalds 81151f4e2bSMauro Carvalho Chehab For more information take a look at <file:Documentation/power/swsusp.rst>. 821da177e4SLinus Torvalds 83c4f39a6cSDomenico Andreoliconfig HIBERNATION_SNAPSHOT_DEV 84c4f39a6cSDomenico Andreoli bool "Userspace snapshot device" 85c4f39a6cSDomenico Andreoli depends on HIBERNATION 86c4f39a6cSDomenico Andreoli default y 87a7f7f624SMasahiro Yamada help 88c4f39a6cSDomenico Andreoli Device used by the uswsusp tools. 89c4f39a6cSDomenico Andreoli 90c4f39a6cSDomenico Andreoli Say N if no snapshotting from userspace is needed, this also 91c4f39a6cSDomenico Andreoli reduces the attack surface of the kernel. 92c4f39a6cSDomenico Andreoli 93c4f39a6cSDomenico Andreoli If in doubt, say Y. 94c4f39a6cSDomenico Andreoli 95a06c6f5dSNikhil Vchoice 96a06c6f5dSNikhil V prompt "Default compressor" 97a06c6f5dSNikhil V default HIBERNATION_COMP_LZO 98a06c6f5dSNikhil V depends on HIBERNATION 99a06c6f5dSNikhil V 100a06c6f5dSNikhil Vconfig HIBERNATION_COMP_LZO 101a06c6f5dSNikhil V bool "lzo" 102a06c6f5dSNikhil V depends on CRYPTO_LZO 103a06c6f5dSNikhil V 104*8bc29736SNikhil Vconfig HIBERNATION_COMP_LZ4 105*8bc29736SNikhil V bool "lz4" 106*8bc29736SNikhil V depends on CRYPTO_LZ4 107*8bc29736SNikhil V 108a06c6f5dSNikhil Vendchoice 109a06c6f5dSNikhil V 110a06c6f5dSNikhil Vconfig HIBERNATION_DEF_COMP 111a06c6f5dSNikhil V string 112a06c6f5dSNikhil V default "lzo" if HIBERNATION_COMP_LZO 113*8bc29736SNikhil V default "lz4" if HIBERNATION_COMP_LZ4 114a06c6f5dSNikhil V help 115a06c6f5dSNikhil V Default compressor to be used for hibernation. 116a06c6f5dSNikhil V 1171da177e4SLinus Torvaldsconfig PM_STD_PARTITION 1181da177e4SLinus Torvalds string "Default resume partition" 119b0cb1a19SRafael J. Wysocki depends on HIBERNATION 1201da177e4SLinus Torvalds default "" 121a7f7f624SMasahiro Yamada help 1221da177e4SLinus Torvalds The default resume partition is the partition that the suspend- 1231da177e4SLinus Torvalds to-disk implementation will look for a suspended disk image. 1241da177e4SLinus Torvalds 1251da177e4SLinus Torvalds The partition specified here will be different for almost every user. 1261da177e4SLinus Torvalds It should be a valid swap partition (at least for now) that is turned 1271da177e4SLinus Torvalds on before suspending. 1281da177e4SLinus Torvalds 1291da177e4SLinus Torvalds The partition specified can be overridden by specifying: 1301da177e4SLinus Torvalds 1311da177e4SLinus Torvalds resume=/dev/<other device> 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds which will set the resume partition to the device specified. 1341da177e4SLinus Torvalds 1351da177e4SLinus Torvalds Note there is currently not a way to specify which device to save the 1361da177e4SLinus Torvalds suspended image to. It will simply pick the first available swap 1371da177e4SLinus Torvalds device. 1381da177e4SLinus Torvalds 139196ec243SRafael J. Wysockiconfig PM_SLEEP 140cf4fb80cSJan Beulich def_bool y 141d419e4c0SShriram Rajagopalan depends on SUSPEND || HIBERNATE_CALLBACKS 142464ed18eSRafael J. Wysocki select PM 143196ec243SRafael J. Wysocki 144196ec243SRafael J. Wysockiconfig PM_SLEEP_SMP 145cf4fb80cSJan Beulich def_bool y 146196ec243SRafael J. Wysocki depends on SMP 147196ec243SRafael J. Wysocki depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE 148196ec243SRafael J. Wysocki depends on PM_SLEEP 149196ec243SRafael J. Wysocki select HOTPLUG_CPU 150196ec243SRafael J. Wysocki 1519ca12ac0SNicholas Pigginconfig PM_SLEEP_SMP_NONZERO_CPU 1529ca12ac0SNicholas Piggin def_bool y 1539ca12ac0SNicholas Piggin depends on PM_SLEEP_SMP 1549ca12ac0SNicholas Piggin depends on ARCH_SUSPEND_NONZERO_CPU 155a7f7f624SMasahiro Yamada help 1569ca12ac0SNicholas Piggin If an arch can suspend (for suspend, hibernate, kexec, etc) on a 1579ca12ac0SNicholas Piggin non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This 1589ca12ac0SNicholas Piggin will allow nohz_full mask to include CPU0. 1599ca12ac0SNicholas Piggin 1607483b4a4SRafael J. Wysockiconfig PM_AUTOSLEEP 1617483b4a4SRafael J. Wysocki bool "Opportunistic sleep" 1627483b4a4SRafael J. Wysocki depends on PM_SLEEP 163a7f7f624SMasahiro Yamada help 1647483b4a4SRafael J. Wysocki Allow the kernel to trigger a system transition into a global sleep 1657483b4a4SRafael J. Wysocki state automatically whenever there are no active wakeup sources. 1667483b4a4SRafael J. Wysocki 167261e224dSKalesh Singhconfig PM_USERSPACE_AUTOSLEEP 168261e224dSKalesh Singh bool "Userspace opportunistic sleep" 169261e224dSKalesh Singh depends on PM_SLEEP 170261e224dSKalesh Singh help 171261e224dSKalesh Singh Notify kernel of aggressive userspace autosleep power management policy. 172261e224dSKalesh Singh 173261e224dSKalesh Singh This option changes the behavior of various sleep-sensitive code to deal 174261e224dSKalesh Singh with frequent userspace-initiated transitions into a global sleep state. 175261e224dSKalesh Singh 176261e224dSKalesh Singh Saying Y here, disables code paths that most users really should keep 177261e224dSKalesh Singh enabled. In particular, only enable this if it is very common to be 178261e224dSKalesh Singh asleep/awake for very short periods of time (<= 2 seconds). 179261e224dSKalesh Singh 180261e224dSKalesh Singh Only platforms, such as Android, that implement opportunistic sleep from 181261e224dSKalesh Singh a userspace power manager service should enable this option; and not 182261e224dSKalesh Singh other machines. Therefore, you should say N here, unless you are 183261e224dSKalesh Singh extremely certain that this is what you want. The option otherwise has 184261e224dSKalesh Singh bad, undesirable effects, and should not be enabled just for fun. 185261e224dSKalesh Singh 186261e224dSKalesh Singh 187b86ff982SRafael J. Wysockiconfig PM_WAKELOCKS 188b86ff982SRafael J. Wysocki bool "User space wakeup sources interface" 189b86ff982SRafael J. Wysocki depends on PM_SLEEP 190a7f7f624SMasahiro Yamada help 191b86ff982SRafael J. Wysocki Allow user space to create, activate and deactivate wakeup source 192b86ff982SRafael J. Wysocki objects with the help of a sysfs-based interface. 193b86ff982SRafael J. Wysocki 194c73893e2SRafael J. Wysockiconfig PM_WAKELOCKS_LIMIT 195c73893e2SRafael J. Wysocki int "Maximum number of user space wakeup sources (0 = no limit)" 196c73893e2SRafael J. Wysocki range 0 100000 197c73893e2SRafael J. Wysocki default 100 198c73893e2SRafael J. Wysocki depends on PM_WAKELOCKS 199c73893e2SRafael J. Wysocki 2004e585d25SRafael J. Wysockiconfig PM_WAKELOCKS_GC 2014e585d25SRafael J. Wysocki bool "Garbage collector for user space wakeup sources" 2024e585d25SRafael J. Wysocki depends on PM_WAKELOCKS 2034e585d25SRafael J. Wysocki default y 2044e585d25SRafael J. Wysocki 205464ed18eSRafael J. Wysockiconfig PM 206464ed18eSRafael J. Wysocki bool "Device power management core functionality" 207a7f7f624SMasahiro Yamada help 208196ec243SRafael J. Wysocki Enable functionality allowing I/O devices to be put into energy-saving 209464ed18eSRafael J. Wysocki (low power) states, for example after a specified period of inactivity 210464ed18eSRafael J. Wysocki (autosuspended), and woken up in response to a hardware-generated 211196ec243SRafael J. Wysocki wake-up event or a driver's request. 212196ec243SRafael J. Wysocki 213196ec243SRafael J. Wysocki Hardware support is generally required for this functionality to work 214196ec243SRafael J. Wysocki and the bus type drivers of the buses the devices are on are 215464ed18eSRafael J. Wysocki responsible for the actual handling of device suspend requests and 216196ec243SRafael J. Wysocki wake-up events. 217196ec243SRafael J. Wysocki 218196ec243SRafael J. Wysockiconfig PM_DEBUG 219196ec243SRafael J. Wysocki bool "Power Management Debug Support" 220196ec243SRafael J. Wysocki depends on PM 221a7f7f624SMasahiro Yamada help 222196ec243SRafael J. Wysocki This option enables various debugging support in the Power Management 223196ec243SRafael J. Wysocki code. This is helpful when debugging and reporting PM bugs, like 224196ec243SRafael J. Wysocki suspend support. 225196ec243SRafael J. Wysocki 226196ec243SRafael J. Wysockiconfig PM_ADVANCED_DEBUG 227196ec243SRafael J. Wysocki bool "Extra PM attributes in sysfs for low-level debugging/testing" 228196ec243SRafael J. Wysocki depends on PM_DEBUG 229a7f7f624SMasahiro Yamada help 230196ec243SRafael J. Wysocki Add extra sysfs attributes allowing one to access some Power Management 231196ec243SRafael J. Wysocki fields of device objects from user space. If you are not a kernel 232196ec243SRafael J. Wysocki developer interested in debugging/testing Power Management, say "no". 233196ec243SRafael J. Wysocki 234196ec243SRafael J. Wysockiconfig PM_TEST_SUSPEND 235196ec243SRafael J. Wysocki bool "Test suspend/resume and wakealarm during bootup" 236196ec243SRafael J. Wysocki depends on SUSPEND && PM_DEBUG && RTC_CLASS=y 237a7f7f624SMasahiro Yamada help 238196ec243SRafael J. Wysocki This option will let you suspend your machine during bootup, and 239196ec243SRafael J. Wysocki make it wake up a few seconds later using an RTC wakeup alarm. 240196ec243SRafael J. Wysocki Enable this with a kernel parameter like "test_suspend=mem". 241196ec243SRafael J. Wysocki 242196ec243SRafael J. Wysocki You probably want to have your system's RTC driver statically 243196ec243SRafael J. Wysocki linked, ensuring that it's available when this test runs. 244196ec243SRafael J. Wysocki 245b2df1d4fSRafael J. Wysockiconfig PM_SLEEP_DEBUG 246196ec243SRafael J. Wysocki def_bool y 24788a6f33eSRafael J. Wysocki depends on PM_DEBUG && PM_SLEEP 248196ec243SRafael J. Wysocki 24970fea60dSBenoit Gobyconfig DPM_WATCHDOG 25070fea60dSBenoit Goby bool "Device suspend/resume watchdog" 2515b3f249cSChen Yu depends on PM_DEBUG && PSTORE && EXPERT 252a7f7f624SMasahiro Yamada help 25370fea60dSBenoit Goby Sets up a watchdog timer to capture drivers that are 25470fea60dSBenoit Goby locked up attempting to suspend/resume a device. 25570fea60dSBenoit Goby A detected lockup causes system panic with message 25670fea60dSBenoit Goby captured in pstore device for inspection in subsequent 25770fea60dSBenoit Goby boot session. 25870fea60dSBenoit Goby 25970fea60dSBenoit Gobyconfig DPM_WATCHDOG_TIMEOUT 26070fea60dSBenoit Goby int "Watchdog timeout in seconds" 26170fea60dSBenoit Goby range 1 120 2625b3f249cSChen Yu default 120 26370fea60dSBenoit Goby depends on DPM_WATCHDOG 26470fea60dSBenoit Goby 265196ec243SRafael J. Wysockiconfig PM_TRACE 266196ec243SRafael J. Wysocki bool 267196ec243SRafael J. Wysocki help 268196ec243SRafael J. Wysocki This enables code to save the last PM event point across 269196ec243SRafael J. Wysocki reboot. The architecture needs to support this, x86 for 270196ec243SRafael J. Wysocki example does by saving things in the RTC, see below. 271196ec243SRafael J. Wysocki 272196ec243SRafael J. Wysocki The architecture specific code must provide the extern 273196ec243SRafael J. Wysocki functions from <linux/resume-trace.h> as well as the 274196ec243SRafael J. Wysocki <asm/resume-trace.h> header with a TRACE_RESUME() macro. 275196ec243SRafael J. Wysocki 276196ec243SRafael J. Wysocki The way the information is presented is architecture- 277196ec243SRafael J. Wysocki dependent, x86 will print the information during a 278196ec243SRafael J. Wysocki late_initcall. 279196ec243SRafael J. Wysocki 280196ec243SRafael J. Wysockiconfig PM_TRACE_RTC 281196ec243SRafael J. Wysocki bool "Suspend/resume event tracing" 282b2df1d4fSRafael J. Wysocki depends on PM_SLEEP_DEBUG 283196ec243SRafael J. Wysocki depends on X86 284196ec243SRafael J. Wysocki select PM_TRACE 285a7f7f624SMasahiro Yamada help 286196ec243SRafael J. Wysocki This enables some cheesy code to save the last PM event point in the 287196ec243SRafael J. Wysocki RTC across reboots, so that you can debug a machine that just hangs 288196ec243SRafael J. Wysocki during suspend (or more commonly, during resume). 289196ec243SRafael J. Wysocki 290196ec243SRafael J. Wysocki To use this debugging feature you should attempt to suspend the 291196ec243SRafael J. Wysocki machine, reboot it and then run 292196ec243SRafael J. Wysocki 293196ec243SRafael J. Wysocki dmesg -s 1000000 | grep 'hash matches' 294196ec243SRafael J. Wysocki 295196ec243SRafael J. Wysocki CAUTION: this option will cause your machine's real-time clock to be 296196ec243SRafael J. Wysocki set to an invalid time after a resume. 297196ec243SRafael J. Wysocki 2987726942fSRalf Baechleconfig APM_EMULATION 2997726942fSRalf Baechle tristate "Advanced Power Management Emulation" 300993e9fe1SArnd Bergmann depends on SYS_SUPPORTS_APM_EMULATION 3017726942fSRalf Baechle help 3027726942fSRalf Baechle APM is a BIOS specification for saving power using several different 3037726942fSRalf Baechle techniques. This is mostly useful for battery powered laptops with 3047726942fSRalf Baechle APM compliant BIOSes. If you say Y here, the system time will be 3057726942fSRalf Baechle reset after a RESUME operation, the /proc/apm device will provide 3067726942fSRalf Baechle battery status information, and user-space programs will receive 3077726942fSRalf Baechle notification of APM "events" (e.g. battery status change). 3087726942fSRalf Baechle 3097726942fSRalf Baechle In order to use APM, you will need supporting software. For location 310151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 3112dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 3127726942fSRalf Baechle <http://www.tldp.org/docs.html#howto>. 3137726942fSRalf Baechle 3147726942fSRalf Baechle This driver does not spin down disk drives (see the hdparm(8) 3157726942fSRalf Baechle manpage ("man 8 hdparm") for that), and it doesn't turn off 3167726942fSRalf Baechle VESA-compliant "green" monitors. 3177726942fSRalf Baechle 3187726942fSRalf Baechle Generally, if you don't have a battery in your machine, there isn't 3197726942fSRalf Baechle much point in using this driver and you should say N. If you get 3207726942fSRalf Baechle random kernel OOPSes or reboots that don't seem to be related to 3217726942fSRalf Baechle anything, try disabling/enabling this option (or disabling/enabling 3227726942fSRalf Baechle APM in your BIOS). 3235e928f77SRafael J. Wysocki 324b7b95920SRafael J. Wysockiconfig PM_CLK 32585eb8c8dSRafael J. Wysocki def_bool y 326b7b95920SRafael J. Wysocki depends on PM && HAVE_CLK 327f721889fSRafael J. Wysocki 328f721889fSRafael J. Wysockiconfig PM_GENERIC_DOMAINS 329f721889fSRafael J. Wysocki bool 330f721889fSRafael J. Wysocki depends on PM 33117f2ae7fSRafael J. Wysocki 332cee22a15SViresh Kumarconfig WQ_POWER_EFFICIENT_DEFAULT 333cee22a15SViresh Kumar bool "Enable workqueue power-efficient mode by default" 334cee22a15SViresh Kumar depends on PM 335cee22a15SViresh Kumar help 336cee22a15SViresh Kumar Per-cpu workqueues are generally preferred because they show 337cee22a15SViresh Kumar better performance thanks to cache locality; unfortunately, 338cee22a15SViresh Kumar per-cpu workqueues tend to be more power hungry than unbound 339cee22a15SViresh Kumar workqueues. 340cee22a15SViresh Kumar 341cee22a15SViresh Kumar Enabling workqueue.power_efficient kernel parameter makes the 342cee22a15SViresh Kumar per-cpu workqueues which were observed to contribute 343cee22a15SViresh Kumar significantly to power consumption unbound, leading to measurably 344cee22a15SViresh Kumar lower power usage at the cost of small performance overhead. 345cee22a15SViresh Kumar 346cee22a15SViresh Kumar This config option determines whether workqueue.power_efficient 347cee22a15SViresh Kumar is enabled by default. 348cee22a15SViresh Kumar 349cee22a15SViresh Kumar If in doubt, say N. 350cee22a15SViresh Kumar 35177f827deSRafael J. Wysockiconfig PM_GENERIC_DOMAINS_SLEEP 35277f827deSRafael J. Wysocki def_bool y 35377f827deSRafael J. Wysocki depends on PM_SLEEP && PM_GENERIC_DOMAINS 35477f827deSRafael J. Wysocki 355aa42240aSTomasz Figaconfig PM_GENERIC_DOMAINS_OF 356aa42240aSTomasz Figa def_bool y 357a4a8c2c4STomasz Figa depends on PM_GENERIC_DOMAINS && OF 358aa42240aSTomasz Figa 359ab10023eSColin Crossconfig CPU_PM 360ab10023eSColin Cross bool 36127871f7aSQuentin Perret 36227871f7aSQuentin Perretconfig ENERGY_MODEL 3633af2f0aaSLukasz Luba bool "Energy Model for devices with DVFS (CPUs, GPUs, etc)" 36427871f7aSQuentin Perret depends on SMP 36527871f7aSQuentin Perret depends on CPU_FREQ 36627871f7aSQuentin Perret help 36727871f7aSQuentin Perret Several subsystems (thermal and/or the task scheduler for example) 3683af2f0aaSLukasz Luba can leverage information about the energy consumed by devices to 3693af2f0aaSLukasz Luba make smarter decisions. This config option enables the framework 3703af2f0aaSLukasz Luba from which subsystems can access the energy models. 37127871f7aSQuentin Perret 37227871f7aSQuentin Perret The exact usage of the energy model is subsystem-dependent. 37327871f7aSQuentin Perret 37427871f7aSQuentin Perret If in doubt, say N. 375