How to configure the Linux kernel/kernel/power

Howto configure the Linux kernel / kernel / power


 * Option: PM
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Power Management support
 * depends on !IA64_HP_SIM
 * 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  or Tuxmobil - Linux on Mobile Computers at  and the Battery Powered Linux mini-HOWTO, available from .
 * 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.


 * Option: PM_LEGACY
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Legacy Power Management API
 * depends on PM
 * default y
 * Support for pm_register and friends.
 * If unsure, say Y.

option enables verbose debugging support in the Power Management . This is helpful when debugging and reporting various PM bugs, suspend support.
 * Option: PM_DEBUG
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Power Management Debug Support
 * depends on PM


 * Option: SOFTWARE_SUSPEND
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Software Suspend
 * depends on PM && SWAP && (X86 && (!SMP || SUSPEND_SMP)) || ((FVR || PPC32) && !SMP)
 * Enable the possibility of suspending the machine. It doesn't need APM. You may suspend your machine by 'swsusp' or 'shutdown -z ' (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 .

"Default resume partition"
 * Option: PM_STD_PARTITION
 * Kernel Versions: 2.6.15.6 ...
 * depends on SOFTWARE_SUSPEND
 * default ""
 * 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:

=/dev/
 * 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.


 * Option: SWSUSP_ENCRYPT
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Encrypt suspend image
 * depends on SOFTWARE_SUSPEND && CRYPTO=y && (CRYPTO_AES=y || CRYPTO_AES_586=y || CRYPTO_AES_X86_64=y)
 * default ""
 * To prevent data gathering from swap after resume you can encrypt the suspend image with a temporary key that is deleted on resume.
 * Note that the temporary key is stored unencrypted on disk while the system is suspended.


 * Option: SUSPEND_SMP
 * Kernel Versions: 2.6.15.6 ...
 * (on/off)
 * depends on HOTPLUG_CPU && X86 && PM
 * default y

Linux Kernel Configuration