pm24.git/kernel/power/power.h, branch v3.2

PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image

2011-10-16T21:30:38Z

Use threads for LZO compression/decompression on hibernate/thaw. Improve buffering on hibernate/thaw. Calculate/verify CRC32 of the image pages on hibernate/thaw. In my testing, this improved write/read speed by a factor of about two. Signed-off-by: Bojan Smojver Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Freeze kernel threads after preallocating memory

2011-10-16T21:28:52Z

There is a problem with the current ordering of hibernate code which leads to deadlocks in some filesystems' memory shrinkers. Namely, some filesystems use freezable kernel threads that are inactive when the hibernate memory preallocation is carried out. Those same filesystems use memory shrinkers that may be triggered by the hibernate memory preallocation. If those memory shrinkers wait for the frozen kernel threads, the hibernate process deadlocks (this happens with XFS, for one example). Apparently, it is not technically viable to redesign the filesystems in question to avoid the situation described above, so the only possible solution of this issue is to defer the freezing of kernel threads until the hibernate memory preallocation is done, which is implemented by this change. Unfortunately, this requires the memory preallocation to be done before the "prepare" stage of device freeze, so after this change the only way drivers can allocate additional memory for their freeze routines in a clean way is to use PM notifiers. Reported-by: Christoph Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Add sysfs knob to control size of memory for drivers

2011-05-17T21:19:19Z

Martin reports that on his system hibernation occasionally fails due to the lack of memory, because the radeon driver apparently allocates too much of it during the device freeze stage. It turns out that the amount of memory allocated by radeon during hibernation (and presumably during system suspend too) depends on the utilization of the GPU (e.g. hibernating while there are two KDE 4 sessions with compositing enabled causes radeon to allocate more memory than for one KDE 4 session). In principle it should be possible to use image_size to make the memory preallocation mechanism free enough memory for the radeon driver, but in practice it is not easy to guess the right value because of the way the preallocation code uses image_size. For this reason, it seems reasonable to allow users to control the amount of memory reserved for driver allocations made after the hibernate preallocation, which currently is constant and amounts to 1 MB. Introduce a new sysfs file, /sys/power/reserved_size, whose value will be used as the amount of memory to reserve for the post-preallocation reservations made by device drivers, in bytes. For backwards compatibility, set its default (and initial) value to the currently used number (1 MB). References: https://bugzilla.kernel.org/show_bug.cgi?id=34102 Reported-and-tested-by: Martin Steigerwald Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Make default image size depend on total RAM size

2010-10-16T23:57:43Z

The default hibernation image size is currently hard coded and euqal to 500 MB, which is not a reasonable default on many contemporary systems. Make it equal 2/5 of the total RAM size (this is slightly below the maximum, i.e. 1/2 of the total RAM size, and seems to be generally suitable). Signed-off-by: Rafael J. Wysocki Tested-by: M. Vefa Bicakci

PM / Hibernate: Compress hibernation image with LZO

2010-10-16T23:57:42Z

Compress hibernation image with LZO in order to save on I/O and therefore time to hibernate/thaw. [rjw: Added hibernate=nocompress command line option instead of just nocompress which would be confusing, fixed a couple of compiler warnings, fixed kerneldoc comments, minor cleanups.] Signed-off-by: Bojan Smojver Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Separate block_io

2010-05-10T21:08:18Z

Move block I/O operations to a separate file. It is because it will be used later not only by the swap writer. Signed-off-by: Jiri Slaby Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Snapshot cleanup

2010-05-10T21:08:17Z

Remove support of reads with offset. This means snapshot_read/write_next now does not accept count parameter. It allows to clean up the functions and snapshot handle which no longer needs to care about offsets. /dev/snapshot handler is converted to simple_{read_from,write_to}_buffer which take care of offsets. Signed-off-by: Jiri Slaby Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

PM/Hibernate: Do not release preallocated memory unnecessarily (rev. 2)

2009-09-14T18:26:58Z

Since the hibernation code is now going to use allocations of memory to make enough room for the image, it can also use the page frames allocated at this stage as image page frames. The low-level hibernation code needs to be rearranged for this purpose, but it allows us to avoid freeing a great number of pages and allocating these same pages once again later, so it generally is worth doing. [rev. 2: Take highmem into account correctly.] Signed-off-by: Rafael J. Wysocki

PM/Hibernate: Rename disk.c to hibernate.c

2009-06-12T19:32:33Z

Change the name of kernel/power/disk.c to kernel/power/hibernate.c in analogy with the file names introduced by the changes that separated the suspend to RAM and standby funtionality from the common PM functions. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek

PM: Separate suspend to RAM functionality from core

2009-06-12T19:32:33Z

Move the suspend to RAM and standby code from kernel/power/main.c to two separate files, kernel/power/suspend.c containing the basic functions and kernel/power/suspend_test.c containing the automatic suspend test facility based on the RTC clock alarm. There are no changes in functionality related to these modifications. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek