user/sven/linux.git/kernel/power/power.h, branch v3.4.93

PM / Sleep: Make enter_state() in kernel/power/suspend.c static

2012-02-17T22:36:10Z

The enter_state() function in kernel/power/suspend.c should be static and state_store() in kernel/power/suspend.c should call pm_suspend() instead of it, so make that happen (which also reduces code duplication related to suspend statistics). Signed-off-by: Rafael J. Wysocki Acked-by: Srivatsa S. Bhat

PM / Sleep: Remove unnecessary label from suspend_freeze_processes()

2012-02-13T15:26:13Z

The Finish label in suspend_freeze_processes() is in fact unnecessary and makes the function look more complicated than it really is, so remove that label (along with a few empty lines). Signed-off-by: Rafael J. Wysocki Acked-by: Srivatsa S. Bhat

PM / Freezer: Thaw only kernel threads if freezing of kernel threads fails

2012-02-04T21:23:05Z

If freezing of kernel threads fails, we are expected to automatically thaw tasks in the error recovery path. However, at times, we encounter situations in which we would like the automatic error recovery path to thaw only the kernel threads, because we want to be able to do some more cleanup before we thaw userspace. Something like: error = freeze_kernel_threads(); if (error) { /* Do some cleanup */ /* Only then thaw userspace tasks*/ thaw_processes(); } An example of such a situation is where we freeze/thaw filesystems during suspend/hibernation. There, if freezing of kernel threads fails, we would like to thaw the frozen filesystems before thawing the userspace tasks. So, modify freeze_kernel_threads() to thaw only kernel threads in case of freezing failure. And change suspend_freeze_processes() accordingly. (At the same time, let us also get rid of the rather cryptic usage of the conditional operator (:?) in that function.) [rjw: In fact, this patch fixes a regression introduced during the 3.3 merge window, because without it thaw_processes() may be called before swsusp_free() in some situations and that may lead to massive memory allocation failures.] Signed-off-by: Srivatsa S. Bhat Acked-by: Tejun Heo Acked-by: Nigel Cunningham Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test path

2011-12-06T21:07:59Z

Commit 2aede851ddf08666f68ffc17be446420e9d2a056 (PM / Hibernate: Freeze kernel threads after preallocating memory) moved the freezing of kernel threads to hibernation_snapshot() function. So now, if the call to hibernation_snapshot() returns early due to a successful hibernation test, the caller has to thaw processes to ensure that the system gets back to its original state. But in SNAPSHOT_CREATE_IMAGE hibernation ioctl, the caller does not thaw processes in case hibernation_snapshot() returned due to a successful freezer test. Fix this issue. But note we still send the value of 'in_suspend' (which is now 0) to userspace, because we are not in an error path per-se, and moreover, the value of in_suspend correctly depicts the situation here. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki

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