x86, cacheinfo: Reorganize AMD L3 cache structure
[deliverable/linux.git] / kernel / power / Kconfig
1 config PM
2 bool "Power Management support"
3 depends on !IA64_HP_SIM
4 ---help---
5 "Power Management" means that parts of your computer are shut
6 off or put into a power conserving "sleep" mode if they are not
7 being used. There are two competing standards for doing this: APM
8 and ACPI. If you want to use either one, say Y here and then also
9 to the requisite support below.
10
11 Power Management is most important for battery powered laptop
12 computers; if you have a laptop, check out the Linux Laptop home
13 page on the WWW at <http://www.linux-on-laptops.com/> or
14 Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/>
15 and the Battery Powered Linux mini-HOWTO, available from
16 <http://www.tldp.org/docs.html#howto>.
17
18 Note that, even if you say N here, Linux on the x86 architecture
19 will issue the hlt instruction if nothing is to be done, thereby
20 sending the processor to sleep and saving power.
21
22 config PM_DEBUG
23 bool "Power Management Debug Support"
24 depends on PM
25 ---help---
26 This option enables various debugging support in the Power Management
27 code. This is helpful when debugging and reporting PM bugs, like
28 suspend support.
29
30 config PM_ADVANCED_DEBUG
31 bool "Extra PM attributes in sysfs for low-level debugging/testing"
32 depends on PM_DEBUG
33 default n
34 ---help---
35 Add extra sysfs attributes allowing one to access some Power Management
36 fields of device objects from user space. If you are not a kernel
37 developer interested in debugging/testing Power Management, say "no".
38
39 config PM_VERBOSE
40 bool "Verbose Power Management debugging"
41 depends on PM_DEBUG
42 default n
43 ---help---
44 This option enables verbose messages from the Power Management code.
45
46 config CAN_PM_TRACE
47 def_bool y
48 depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL
49
50 config PM_TRACE
51 bool
52 help
53 This enables code to save the last PM event point across
54 reboot. The architecture needs to support this, x86 for
55 example does by saving things in the RTC, see below.
56
57 The architecture specific code must provide the extern
58 functions from <linux/resume-trace.h> as well as the
59 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
60
61 The way the information is presented is architecture-
62 dependent, x86 will print the information during a
63 late_initcall.
64
65 config PM_TRACE_RTC
66 bool "Suspend/resume event tracing"
67 depends on CAN_PM_TRACE
68 depends on X86
69 select PM_TRACE
70 default n
71 ---help---
72 This enables some cheesy code to save the last PM event point in the
73 RTC across reboots, so that you can debug a machine that just hangs
74 during suspend (or more commonly, during resume).
75
76 To use this debugging feature you should attempt to suspend the
77 machine, reboot it and then run
78
79 dmesg -s 1000000 | grep 'hash matches'
80
81 CAUTION: this option will cause your machine's real-time clock to be
82 set to an invalid time after a resume.
83
84 config PM_SLEEP_SMP
85 bool
86 depends on SMP
87 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
88 depends on PM_SLEEP
89 select HOTPLUG_CPU
90 default y
91
92 config PM_SLEEP
93 bool
94 depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE
95 default y
96
97 config PM_SLEEP_ADVANCED_DEBUG
98 bool
99 depends on PM_ADVANCED_DEBUG
100 default n
101
102 config SUSPEND
103 bool "Suspend to RAM and standby"
104 depends on PM && ARCH_SUSPEND_POSSIBLE
105 default y
106 ---help---
107 Allow the system to enter sleep states in which main memory is
108 powered and thus its contents are preserved, such as the
109 suspend-to-RAM state (e.g. the ACPI S3 state).
110
111 config PM_TEST_SUSPEND
112 bool "Test suspend/resume and wakealarm during bootup"
113 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
114 ---help---
115 This option will let you suspend your machine during bootup, and
116 make it wake up a few seconds later using an RTC wakeup alarm.
117 Enable this with a kernel parameter like "test_suspend=mem".
118
119 You probably want to have your system's RTC driver statically
120 linked, ensuring that it's available when this test runs.
121
122 config SUSPEND_FREEZER
123 bool "Enable freezer for suspend to RAM/standby" \
124 if ARCH_WANTS_FREEZER_CONTROL || BROKEN
125 depends on SUSPEND
126 default y
127 help
128 This allows you to turn off the freezer for suspend. If this is
129 done, no tasks are frozen for suspend to RAM/standby.
130
131 Turning OFF this setting is NOT recommended! If in doubt, say Y.
132
133 config HIBERNATION_NVS
134 bool
135
136 config HIBERNATION
137 bool "Hibernation (aka 'suspend to disk')"
138 depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE
139 select HIBERNATION_NVS if HAS_IOMEM
140 ---help---
141 Enable the suspend to disk (STD) functionality, which is usually
142 called "hibernation" in user interfaces. STD checkpoints the
143 system and powers it off; and restores that checkpoint on reboot.
144
145 You can suspend your machine with 'echo disk > /sys/power/state'
146 after placing resume=/dev/swappartition on the kernel command line
147 in your bootloader's configuration file.
148
149 Alternatively, you can use the additional userland tools available
150 from <http://suspend.sf.net>.
151
152 In principle it does not require ACPI or APM, although for example
153 ACPI will be used for the final steps when it is available. One
154 of the reasons to use software suspend is that the firmware hooks
155 for suspend states like suspend-to-RAM (STR) often don't work very
156 well with Linux.
157
158 It creates an image which is saved in your active swap. Upon the next
159 boot, pass the 'resume=/dev/swappartition' argument to the kernel to
160 have it detect the saved image, restore memory state from it, and
161 continue to run as before. If you do not want the previous state to
162 be reloaded, then use the 'noresume' kernel command line argument.
163 Note, however, that fsck will be run on your filesystems and you will
164 need to run mkswap against the swap partition used for the suspend.
165
166 It also works with swap files to a limited extent (for details see
167 <file:Documentation/power/swsusp-and-swap-files.txt>).
168
169 Right now you may boot without resuming and resume later but in the
170 meantime you cannot use the swap partition(s)/file(s) involved in
171 suspending. Also in this case you must not use the filesystems
172 that were mounted before the suspend. In particular, you MUST NOT
173 MOUNT any journaled filesystems mounted before the suspend or they
174 will get corrupted in a nasty way.
175
176 For more information take a look at <file:Documentation/power/swsusp.txt>.
177
178 config PM_STD_PARTITION
179 string "Default resume partition"
180 depends on HIBERNATION
181 default ""
182 ---help---
183 The default resume partition is the partition that the suspend-
184 to-disk implementation will look for a suspended disk image.
185
186 The partition specified here will be different for almost every user.
187 It should be a valid swap partition (at least for now) that is turned
188 on before suspending.
189
190 The partition specified can be overridden by specifying:
191
192 resume=/dev/<other device>
193
194 which will set the resume partition to the device specified.
195
196 Note there is currently not a way to specify which device to save the
197 suspended image to. It will simply pick the first available swap
198 device.
199
200 config APM_EMULATION
201 tristate "Advanced Power Management Emulation"
202 depends on PM && SYS_SUPPORTS_APM_EMULATION
203 help
204 APM is a BIOS specification for saving power using several different
205 techniques. This is mostly useful for battery powered laptops with
206 APM compliant BIOSes. If you say Y here, the system time will be
207 reset after a RESUME operation, the /proc/apm device will provide
208 battery status information, and user-space programs will receive
209 notification of APM "events" (e.g. battery status change).
210
211 In order to use APM, you will need supporting software. For location
212 and more information, read <file:Documentation/power/pm.txt> and the
213 Battery Powered Linux mini-HOWTO, available from
214 <http://www.tldp.org/docs.html#howto>.
215
216 This driver does not spin down disk drives (see the hdparm(8)
217 manpage ("man 8 hdparm") for that), and it doesn't turn off
218 VESA-compliant "green" monitors.
219
220 Generally, if you don't have a battery in your machine, there isn't
221 much point in using this driver and you should say N. If you get
222 random kernel OOPSes or reboots that don't seem to be related to
223 anything, try disabling/enabling this option (or disabling/enabling
224 APM in your BIOS).
225
226 config PM_RUNTIME
227 bool "Run-time PM core functionality"
228 depends on PM
229 ---help---
230 Enable functionality allowing I/O devices to be put into energy-saving
231 (low power) states at run time (or autosuspended) after a specified
232 period of inactivity and woken up in response to a hardware-generated
233 wake-up event or a driver's request.
234
235 Hardware support is generally required for this functionality to work
236 and the bus type drivers of the buses the devices are on are
237 responsible for the actual handling of the autosuspend requests and
238 wake-up events.
239
240 config PM_OPS
241 bool
242 depends on PM_SLEEP || PM_RUNTIME
243 default y
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