linux.git/kernel/power, branch v6.2

PM: sleep: Refine error message in try_to_freeze_tasks()

2022-12-06T11:04:34+00:00

A previous change amended try_to_freeze_tasks() with the "what"
variable pointing to a string describing the group of tasks subject to
the freezing which may be used in the error message in there too, so
make that happen.

Accordingly, update sleepgraph.py to catch the modified error message
as appropriate.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Petr Mladek

PM: sleep: Avoid using pr_cont() in the tasks freezing code

2022-12-06T11:04:10+00:00

Using pr_cont() in the tasks freezing code related to system-wide
suspend and hibernation is problematic, because the continuation
messages printed there are susceptible to interspersing with other
unrelated messages which results in output that is hard to
understand.

Address this issue by modifying try_to_freeze_tasks() to print
messages that don't require continuations and adjusting its
callers accordingly.

Reported-by: Thomas Weißschuh 
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Petr Mladek

PM: hibernate: Complain about memory map mismatches during resume

2022-12-01T18:20:14+00:00

The system memory map can change over a hibernation-restore cycle due
to a defect in the platform firmware, and some of the page frames used
by the kernel before hibernation may not be available any more during
the subsequent restore which leads to the error below.

[  T357] PM: Image loading progress:   0%
[  T357] PM: Read 2681596 kbytes in 0.03 seconds (89386.53 MB/s)
[  T357] PM: Error -14 resuming
[  T357] PM: Failed to load hibernation image, recovering.
[  T357] PM: Basic memory bitmaps freed
[  T357] OOM killer enabled.
[  T357] Restarting tasks ... done.
[  T357] PM: resume from hibernation failed (-14)
[  T357] PM: Hibernation image not present or could not be loaded.

Add an error message to the unpack() function to allow problematic
page frames to be identified and the source of the problem to be
diagnosed more easily. This can save developers quite a bit of
debugging time.

Signed-off-by: Xueqin Luo 
[ rjw: New subject, edited changelog ]
Signed-off-by: Rafael J. Wysocki

PM: hibernate: Fix mistake in kerneldoc comment

2022-11-03T16:32:58+00:00

The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:

max_size = (count - (size + PAGES_FOR_IO)) / 2
	    - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);

but the one in the kerneldoc comment of the function is different and
incorrect.

Fixes: ddeb64870810 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers")
Signed-off-by: xiongxin 
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki

PM: hibernate: Allow hybrid sleep to work with s2idle

2022-10-25T12:53:19+00:00

Hybrid sleep is currently hardcoded to only operate with S3 even
on systems that might not support it.

Instead of assuming this mode is what the user wants to use, for
hybrid sleep follow the setting of `mem_sleep_current` which
will respect mem_sleep_default kernel command line and policy
decisions made by the presence of the FADT low power idle bit.

Fixes: 81d45bdf8913 ("PM / hibernate: Untangle power_down()")
Reported-and-tested-by: kolAflash 
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216574
Signed-off-by: Mario Limonciello 
Signed-off-by: Rafael J. Wysocki

Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-10-10T16:10:28+00:00

Pull scheduler updates from Ingo Molnar:
 "Debuggability:

   - Change most occurances of BUG_ON() to WARN_ON_ONCE()

   - Reorganize & fix TASK_ state comparisons, turn it into a bitmap

   - Update/fix misc scheduler debugging facilities

  Load-balancing & regular scheduling:

   - Improve the behavior of the scheduler in presence of lot of
     SCHED_IDLE tasks - in particular they should not impact other
     scheduling classes.

   - Optimize task load tracking, cleanups & fixes

   - Clean up & simplify misc load-balancing code

  Freezer:

   - Rewrite the core freezer to behave better wrt thawing and be
     simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
     fixing/adjusting all the fallout.

  Deadline scheduler:

   - Fix the DL capacity-aware code

   - Factor out dl_task_is_earliest_deadline() &
     replenish_dl_new_period()

   - Relax/optimize locking in task_non_contending()

  Cleanups:

   - Factor out the update_current_exec_runtime() helper

   - Various cleanups, simplifications"

* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  sched: Fix more TASK_state comparisons
  sched: Fix TASK_state comparisons
  sched/fair: Move call to list_last_entry() in detach_tasks
  sched/fair: Cleanup loop_max and loop_break
  sched/fair: Make sure to try to detach at least one movable task
  sched: Show PF_flag holes
  freezer,sched: Rewrite core freezer logic
  sched: Widen TAKS_state literals
  sched/wait: Add wait_event_state()
  sched/completion: Add wait_for_completion_state()
  sched: Add TASK_ANY for wait_task_inactive()
  sched: Change wait_task_inactive()s match_state
  freezer,umh: Clean up freezer/initrd interaction
  freezer: Have {,un}lock_system_sleep() save/restore flags
  sched: Rename task_running() to task_on_cpu()
  sched/fair: Cleanup for SIS_PROP
  sched/fair: Default to false in test_idle_cores()
  sched/fair: Remove useless check in select_idle_core()
  sched/fair: Avoid double search on same cpu
  sched/fair: Remove redundant check in select_idle_smt()
  ...

ACPI: s2idle: Add a new ->check() callback for platform_s2idle_ops

2022-09-09T15:37:40+00:00

On some platforms it is found that Linux more aggressively enters s2idle
than Windows enters Modern Standby and this uncovers some synchronization
issues for the platform.  To aid in debugging this class of problems in
the future, add support for an extra optional callback intended for
drivers to emit extra debugging.

Signed-off-by: Mario Limonciello 
Acked-by: Rafael J. Wysocki 
Link: https://lore.kernel.org/r/20220829162953.5947-2-mario.limonciello@amd.com
Signed-off-by: Hans de Goede

freezer,sched: Rewrite core freezer logic

2022-09-07T19:53:50+00:00

Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

	freezer_do_not_count();
	schedule();
	freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

	TASK_FREEZABLE	-> TASK_FROZEN
	__TASK_STOPPED	-> TASK_FROZEN
	__TASK_TRACED	-> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Ingo Molnar 
Acked-by: Rafael J. Wysocki 
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org

freezer: Have {,un}lock_system_sleep() save/restore flags

2022-09-07T19:53:48+00:00

Rafael explained that the reason for having both PF_NOFREEZE and
PF_FREEZER_SKIP is that {,un}lock_system_sleep() is callable from
kthread context that has previously called set_freezable().

In preparation of merging the flags, have {,un}lock_system_slee() save
and restore current->flags.

Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Rafael J. Wysocki 
Link: https://lore.kernel.org/r/20220822114648.725003428@infradead.org

Merge tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2022-08-04T18:05:48+00:00

Pull char / misc driver updates from Greg KH:
 "Here is the large set of char and misc and other driver subsystem
  changes for 6.0-rc1.

  Highlights include:

   - large set of IIO driver updates, additions, and cleanups

   - new habanalabs device support added (loads of register maps much
     like GPUs have)

   - soundwire driver updates

   - phy driver updates

   - slimbus driver updates

   - tiny virt driver fixes and updates

   - misc driver fixes and updates

   - interconnect driver updates

   - hwtracing driver updates

   - fpga driver updates

   - extcon driver updates

   - firmware driver updates

   - counter driver update

   - mhi driver fixes and updates

   - binder driver fixes and updates

   - speakup driver fixes

  All of these have been in linux-next for a while without any reported
  problems"

* tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (634 commits)
  drivers: lkdtm: fix clang -Wformat warning
  char: remove VR41XX related char driver
  misc: Mark MICROCODE_MINOR unused
  spmi: trace: fix stack-out-of-bound access in SPMI tracing functions
  dt-bindings: iio: adc: Add compatible for MT8188
  iio: light: isl29028: Fix the warning in isl29028_remove()
  iio: accel: sca3300: Extend the trigger buffer from 16 to 32 bytes
  iio: fix iio_format_avail_range() printing for none IIO_VAL_INT
  iio: adc: max1027: unlock on error path in max1027_read_single_value()
  iio: proximity: sx9324: add empty line in front of bullet list
  iio: magnetometer: hmc5843: Remove duplicate 'the'
  iio: magn: yas530: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: magnetometer: ak8974: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: veml6030: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4035: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4000: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: tsl2591: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: tsl2583: Use DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  iio: light: isl29028: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: gp2ap002: Switch to DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  ...