config PM bool "Power Management support" depends on !IA64_HP_SIM ---help--- "Power Management" means that parts of your computer are shut off or put into a power conserving "sleep" mode if they are not being used. There are two competing standards for doing this: APM and ACPI. If you want to use either one, say Y here and then also to the requisite support below. Power Management is most important for battery powered laptop computers; if you have a laptop, check out the Linux Laptop home page on the WWW at <http://www.linux-on-laptops.com/> or Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/> and the Battery Powered Linux mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>. Note that, even if you say N here, Linux on the x86 architecture will issue the hlt instruction if nothing is to be done, thereby sending the processor to sleep and saving power. config PM_LEGACY bool "Legacy Power Management API" depends on PM default y ---help--- Support for pm_register() and friends. If unsure, say Y. config PM_DEBUG bool "Power Management Debug Support" depends on PM ---help--- This option enables verbose debugging support in the Power Management code. This is helpful when debugging and reporting various PM bugs, like suspend support. config DISABLE_CONSOLE_SUSPEND bool "Keep console(s) enabled during suspend/resume (DANGEROUS)" depends on PM && PM_DEBUG default n ---help--- This option turns off the console suspend mechanism that prevents debug messages from reaching the console during the suspend/resume operations. This may be helpful when debugging device drivers' suspend/resume routines, but may itself lead to problems, for example if netconsole is used. config PM_TRACE bool "Suspend/resume event tracing" depends on PM && PM_DEBUG && X86_32 && EXPERIMENTAL default n ---help--- This enables some cheesy code to save the last PM event point in the RTC across reboots, so that you can debug a machine that just hangs during suspend (or more commonly, during resume). To use this debugging feature you should attempt to suspend the machine, then reboot it, then run dmesg -s 1000000 | grep 'hash matches' CAUTION: this option will cause your machine's real-time clock to be set to an invalid time after a resume. config PM_SYSFS_DEPRECATED bool "Driver model /sys/devices/.../power/state files (DEPRECATED)" depends on PM && SYSFS default n help The driver model started out with a sysfs file intended to provide a userspace hook for device power management. This feature has never worked very well, except for limited testing purposes, and so it will be removed. It's not clear that a generic mechanism could really handle the wide variability of device power states; any replacements are likely to be bus or driver specific. config SOFTWARE_SUSPEND bool "Software Suspend" depends on PM && SWAP && ((X86 && (!SMP || SUSPEND_SMP) && !X86_PAE) || ((FRV || PPC32) && !SMP)) ---help--- Enable the possibility of suspending the machine. It doesn't need ACPI or APM. You may suspend your machine by 'swsusp' or 'shutdown -z <time>' (patch for sysvinit needed). It creates an image which is saved in your active swap. Upon next boot, pass the 'resume=/dev/swappartition' argument to the kernel to have it detect the saved image, restore memory state from it, and continue to run as before. If you do not want the previous state to be reloaded, then use the 'noresume' kernel argument. However, note that your partitions will be fsck'd and you must re-mkswap your swap partitions. It does not work with swap files. Right now you may boot without resuming and then later resume but in meantime you cannot use those swap partitions/files which were involved in suspending. Also in this case there is a risk that buffers on disk won't match with saved ones. For more information take a look at <file:Documentation/power/swsusp.txt>. (For now, swsusp is incompatible with PAE aka HIGHMEM_64G on i386. we need identity mapping for resume to work, and that is trivial to get with 4MB pages, but less than trivial on PAE). config PM_STD_PARTITION string "Default resume partition" depends on SOFTWARE_SUSPEND default "" ---help--- The default resume partition is the partition that the suspend- to-disk implementation will look for a suspended disk image. The partition specified here will be different for almost every user. It should be a valid swap partition (at least for now) that is turned on before suspending. The partition specified can be overridden by specifying: resume=/dev/<other device> which will set the resume partition to the device specified. Note there is currently not a way to specify which device to save the suspended image to. It will simply pick the first available swap device. config SUSPEND_SMP bool depends on HOTPLUG_CPU && X86 && PM default y