X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Fpower%2Fswsusp.txt;h=9d60ab717a7b3c8dc0daa4d14e6a914884965bf0;hb=1f6d6e8ebe73ba9d9d4c693f7f6f50f661dbd6e4;hp=c55bd5079b90e4ddc654fb8755e93bfca8144560;hpb=5f757f91e70a97eda8f0cc13bddc853209b2d173;p=linux-2.6-omap-h63xx.git diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt index c55bd5079b9..9d60ab717a7 100644 --- a/Documentation/power/swsusp.txt +++ b/Documentation/power/swsusp.txt @@ -48,7 +48,7 @@ before suspend (it is limited to 500 MB by default). Article about goals and implementation of Software Suspend for Linux ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Author: G‚ábor Kuti +Author: G‚ábor Kuti Last revised: 2003-10-20 by Pavel Machek Idea and goals to achieve @@ -140,21 +140,11 @@ should be sent to the mailing list available through the suspend2 website, and not to the Linux Kernel Mailing List. We are working toward merging suspend2 into the mainline kernel. -Q: A kernel thread must voluntarily freeze itself (call 'refrigerator'). -I found some kernel threads that don't do it, and they don't freeze -so the system can't sleep. Is this a known behavior? - -A: All such kernel threads need to be fixed, one by one. Select the -place where the thread is safe to be frozen (no kernel semaphores -should be held at that point and it must be safe to sleep there), and -add: - - try_to_freeze(); - -If the thread is needed for writing the image to storage, you should -instead set the PF_NOFREEZE process flag when creating the thread (and -be very careful). +Q: What is the freezing of tasks and why are we using it? +A: The freezing of tasks is a mechanism by which user space processes and some +kernel threads are controlled during hibernation or system-wide suspend (on some +architectures). See freezing-of-tasks.txt for details. Q: What is the difference between "platform" and "shutdown"? @@ -393,6 +383,14 @@ safest thing is to unmount all filesystems on removable media (such USB, Firewire, CompactFlash, MMC, external SATA, or even IDE hotplug bays) before suspending; then remount them after resuming. +There is a work-around for this problem. For more information, see +Documentation/usb/persist.txt. + +Q: Can I suspend-to-disk using a swap partition under LVM? + +A: No. You can suspend successfully, but you'll not be able to +resume. uswsusp should be able to work with LVM. See suspend.sf.net. + Q: I upgraded the kernel from 2.6.15 to 2.6.16. Both kernels were compiled with the similar configuration files. Anyway I found that suspend to disk (and resume) is much slower on 2.6.16 compared to