1*1da177e4SLinus Torvaldsconfig PM 2*1da177e4SLinus Torvalds bool "Power Management support" 3*1da177e4SLinus Torvalds ---help--- 4*1da177e4SLinus Torvalds "Power Management" means that parts of your computer are shut 5*1da177e4SLinus Torvalds off or put into a power conserving "sleep" mode if they are not 6*1da177e4SLinus Torvalds being used. There are two competing standards for doing this: APM 7*1da177e4SLinus Torvalds and ACPI. If you want to use either one, say Y here and then also 8*1da177e4SLinus Torvalds to the requisite support below. 9*1da177e4SLinus Torvalds 10*1da177e4SLinus Torvalds Power Management is most important for battery powered laptop 11*1da177e4SLinus Torvalds computers; if you have a laptop, check out the Linux Laptop home 12*1da177e4SLinus Torvalds page on the WWW at <http://www.linux-on-laptops.com/> or 13*1da177e4SLinus Torvalds Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/> 14*1da177e4SLinus Torvalds and the Battery Powered Linux mini-HOWTO, available from 15*1da177e4SLinus Torvalds <http://www.tldp.org/docs.html#howto>. 16*1da177e4SLinus Torvalds 17*1da177e4SLinus Torvalds Note that, even if you say N here, Linux on the x86 architecture 18*1da177e4SLinus Torvalds will issue the hlt instruction if nothing is to be done, thereby 19*1da177e4SLinus Torvalds sending the processor to sleep and saving power. 20*1da177e4SLinus Torvalds 21*1da177e4SLinus Torvaldsconfig PM_DEBUG 22*1da177e4SLinus Torvalds bool "Power Management Debug Support" 23*1da177e4SLinus Torvalds depends on PM 24*1da177e4SLinus Torvalds ---help--- 25*1da177e4SLinus Torvalds This option enables verbose debugging support in the Power Management 26*1da177e4SLinus Torvalds code. This is helpful when debugging and reporting various PM bugs, 27*1da177e4SLinus Torvalds like suspend support. 28*1da177e4SLinus Torvalds 29*1da177e4SLinus Torvaldsconfig SOFTWARE_SUSPEND 30*1da177e4SLinus Torvalds bool "Software Suspend (EXPERIMENTAL)" 31*1da177e4SLinus Torvalds depends on EXPERIMENTAL && PM && SWAP 32*1da177e4SLinus Torvalds ---help--- 33*1da177e4SLinus Torvalds Enable the possibility of suspending the machine. 34*1da177e4SLinus Torvalds It doesn't need APM. 35*1da177e4SLinus Torvalds You may suspend your machine by 'swsusp' or 'shutdown -z <time>' 36*1da177e4SLinus Torvalds (patch for sysvinit needed). 37*1da177e4SLinus Torvalds 38*1da177e4SLinus Torvalds It creates an image which is saved in your active swap. Upon next 39*1da177e4SLinus Torvalds boot, pass the 'resume=/dev/swappartition' argument to the kernel to 40*1da177e4SLinus Torvalds have it detect the saved image, restore memory state from it, and 41*1da177e4SLinus Torvalds continue to run as before. If you do not want the previous state to 42*1da177e4SLinus Torvalds be reloaded, then use the 'noresume' kernel argument. However, note 43*1da177e4SLinus Torvalds that your partitions will be fsck'd and you must re-mkswap your swap 44*1da177e4SLinus Torvalds partitions. It does not work with swap files. 45*1da177e4SLinus Torvalds 46*1da177e4SLinus Torvalds Right now you may boot without resuming and then later resume but 47*1da177e4SLinus Torvalds in meantime you cannot use those swap partitions/files which were 48*1da177e4SLinus Torvalds involved in suspending. Also in this case there is a risk that buffers 49*1da177e4SLinus Torvalds on disk won't match with saved ones. 50*1da177e4SLinus Torvalds 51*1da177e4SLinus Torvalds For more information take a look at <file:Documentation/power/swsusp.txt>. 52*1da177e4SLinus Torvalds 53*1da177e4SLinus Torvaldsconfig PM_STD_PARTITION 54*1da177e4SLinus Torvalds string "Default resume partition" 55*1da177e4SLinus Torvalds depends on SOFTWARE_SUSPEND 56*1da177e4SLinus Torvalds default "" 57*1da177e4SLinus Torvalds ---help--- 58*1da177e4SLinus Torvalds The default resume partition is the partition that the suspend- 59*1da177e4SLinus Torvalds to-disk implementation will look for a suspended disk image. 60*1da177e4SLinus Torvalds 61*1da177e4SLinus Torvalds The partition specified here will be different for almost every user. 62*1da177e4SLinus Torvalds It should be a valid swap partition (at least for now) that is turned 63*1da177e4SLinus Torvalds on before suspending. 64*1da177e4SLinus Torvalds 65*1da177e4SLinus Torvalds The partition specified can be overridden by specifying: 66*1da177e4SLinus Torvalds 67*1da177e4SLinus Torvalds resume=/dev/<other device> 68*1da177e4SLinus Torvalds 69*1da177e4SLinus Torvalds which will set the resume partition to the device specified. 70*1da177e4SLinus Torvalds 71*1da177e4SLinus Torvalds Note there is currently not a way to specify which device to save the 72*1da177e4SLinus Torvalds suspended image to. It will simply pick the first available swap 73*1da177e4SLinus Torvalds device. 74*1da177e4SLinus Torvalds 75