config PM
bool "Power Management support"
---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.cs.utexas.edu/users/kharker/linux-laptop/> 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 SOFTWARE_SUSPEND
bool "Software Suspend (EXPERIMENTAL)"
depends on EXPERIMENTAL && PM && SWAP
---help---
Enable the possibilty of suspendig machine. It doesn't need 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 swaps. By the next
booting the, pass 'resume=/dev/swappartition' and kernel will
detect the saved image, restore the memory from
it and then it continues to run as before you've suspended.
If you don't want the previous state to continue use the 'noresume'
kernel option. 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 Documentation/swsusp.txt.
config PM_DISK
bool "Suspend-to-Disk Support"
depends on PM && SWAP
---help---
Suspend-to-disk is a power management state in which the contents
of memory are stored on disk and the entire system is shut down or
put into a low-power state (e.g. ACPI S4). When the computer is
turned back on, the stored image is loaded from disk and execution
resumes from where it left off before suspending.
This config option enables the core infrastructure necessary to
perform the suspend and resume transition.
Currently, this suspend-to-disk implementation is based on a forked
version of the swsusp code base. As such, it's still experimental,
and still relies on CONFIG_SWAP.
More information can be found in Documentation/power/.
If unsure, Say N.
config PM_DISK_PARTITION
string "Default resume partition"
depends on PM_DISK
default ""
---help---
The default resume partition is the partition that the pmdisk 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:
pmdisk=/dev/<other device>
which will set the resume partition to the device specified.
One may also do:
pmdisk=off
to inform the kernel not to perform a resume transition.
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.