linux-stable.git/drivers/cpuidle, branch v4.19.166

cpuidle: Fixup IRQ state

2020-09-09T17:04:23+00:00

[ Upstream commit 49d9c5936314e44d314c605c39cce0fd947f9c3a ]

Match the pattern elsewhere in this file.

Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Steven Rostedt (VMware) 
Reviewed-by: Thomas Gleixner 
Acked-by: Rafael J. Wysocki 
Tested-by: Marco Elver 
Link: https://lkml.kernel.org/r/20200821085348.251340558@infradead.org
Signed-off-by: Sasha Levin

cpuidle: Fix three reference count leaks

2020-06-22T07:05:20+00:00

[ Upstream commit c343bf1ba5efcbf2266a1fe3baefec9cc82f867f ]

kobject_init_and_add() takes reference even when it fails.
If this function returns an error, kobject_put() must be called to
properly clean up the memory associated with the object.

Previous commit "b8eb718348b8" fixed a similar problem.

Signed-off-by: Qiushi Wu 
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

cpuidle: Do not unset the driver if it is there already

2019-12-17T19:35:00+00:00

commit 918c1fe9fbbe46fcf56837ff21f0ef96424e8b29 upstream.

Fix __cpuidle_set_driver() to check if any of the CPUs in the mask has
a driver different from drv already and, if so, return -EBUSY before
updating any cpuidle_drivers per-CPU pointers.

Fixes: 82467a5a885d ("cpuidle: simplify multiple driver support")
Cc: 3.11+  # 3.11+
Signed-off-by: Zhenzhong Duan 
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpuidle: menu: Fix wakeup statistics updates for polling state

2019-11-24T07:20:07+00:00

[ Upstream commit 5f26bdceb9c0a5e6c696aa2899d077cd3ae93413 ]

If the CPU exits the "polling" state due to the time limit in the
loop in poll_idle(), this is not a real wakeup and it just means
that the "polling" state selection was not adequate.  The governor
mispredicted short idle duration, but had a more suitable state been
selected, the CPU might have spent more time in it.  In fact, there
is no reason to expect that there would have been a wakeup event
earlier than the next timer in that case.

Handling such cases as regular wakeups in menu_update() may cause the
menu governor to make suboptimal decisions going forward, but ignoring
them altogether would not be correct either, because every time
menu_select() is invoked, it makes a separate new attempt to predict
the idle duration taking distinct time to the closest timer event as
input and the outcomes of all those attempts should be recorded.

For this reason, make menu_update() always assume that if the
"polling" state was exited due to the time limit, the next proper
wakeup event for the CPU would be the next timer event (not
including the tick).

Fixes: a37b969a61c1 "cpuidle: poll_state: Add time limit to poll_idle()"
Signed-off-by: Rafael J. Wysocki 
Acked-by: Peter Zijlstra (Intel) 
Reviewed-by: Daniel Lezcano 
Signed-off-by: Sasha Levin

cpuidle: big.LITTLE: fix refcount leak

2019-02-12T18:47:08+00:00

[ Upstream commit 9456823c842f346c74265fcd98d008d87a7eb6f5 ]

of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
bl_idle_init() doesn't do that, so fix it.

Signed-off-by: Yangtao Li 
Acked-by: Daniel Lezcano 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powerpc/pseries/cpuidle: Fix preempt warning

2019-01-26T08:32:37+00:00

[ Upstream commit 2b038cbc5fcf12a7ee1cc9bfd5da1e46dacdee87 ]

When booting a pseries kernel with PREEMPT enabled, it dumps the
following warning:

   BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
   caller is pseries_processor_idle_init+0x5c/0x22c
   CPU: 13 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc3-00090-g12201a0128bc-dirty #828
   Call Trace:
   [c000000429437ab0] [c0000000009c8878] dump_stack+0xec/0x164 (unreliable)
   [c000000429437b00] [c0000000005f2f24] check_preemption_disabled+0x154/0x160
   [c000000429437b90] [c000000000cab8e8] pseries_processor_idle_init+0x5c/0x22c
   [c000000429437c10] [c000000000010ed4] do_one_initcall+0x64/0x300
   [c000000429437ce0] [c000000000c54500] kernel_init_freeable+0x3f0/0x500
   [c000000429437db0] [c0000000000112dc] kernel_init+0x2c/0x160
   [c000000429437e20] [c00000000000c1d0] ret_from_kernel_thread+0x5c/0x6c

This happens because the code calls get_lppaca() which calls
get_paca() and it checks if preemption is disabled through
check_preemption_disabled().

Preemption should be disabled because the per CPU variable may make no
sense if there is a preemption (and a CPU switch) after it reads the
per CPU data and when it is used.

In this device driver specifically, it is not a problem, because this
code just needs to have access to one lppaca struct, and it does not
matter if it is the current per CPU lppaca struct or not (i.e. when
there is a preemption and a CPU migration).

That said, the most appropriate fix seems to be related to avoiding
the debug_smp_processor_id() call at get_paca(), instead of calling
preempt_disable() before get_paca().

Signed-off-by: Breno Leitao 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

ARM: cpuidle: Don't register the driver when back-end init returns -ENXIO

2018-11-21T08:19:23+00:00

commit 763f191af51f127cf8e69cd361f50bf6180768a5 upstream.

There's no point to register the cpuidle driver for the current CPU, when
the initialization of the arch specific back-end data fails by returning
-ENXIO.

Instead, let's re-order the sequence to its original flow, by first trying
to initialize the back-end part and then act accordingly on the returned
error code. Additionally, let's print the error message, no matter of what
error code that was returned.

Fixes: a0d46a3dfdc3 (ARM: cpuidle: Register per cpuidle device)
Signed-off-by: Ulf Hansson 
Reviewed-by: Daniel Lezcano 
Cc: 4.19+  # v4.19+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpuidle: menu: Retain tick when shallow state is selected

2018-08-25T11:16:08+00:00

The case addressed by commit 5ef499cd571c (cpuidle: menu: Handle
stopped tick more aggressively) in the stopped tick case is present
when the tick has not been stopped yet too.  Namely, if only two CPU
idle states, shallow state A with target residency significantly
below the tick boundary and deep state B with target residency
significantly above it, are available and the predicted idle
duration is above the tick boundary, but below the target residency
of state B, state A will be selected and the CPU may spend indefinite
amount of time in it, which is not quite energy-efficient.

However, if the tick has not been stopped yet and the governor is
about to select a shallow idle state for the CPU even though the idle
duration predicted by it is above the tick boundary, it should be
fine to wake up the CPU early, so the tick can be retained then and
the governor will have a chance to select a deeper state when it runs
next time.

[Note that when this really happens, it will make the idle duration
 predictor believe that the CPU might be idle longer than predicted,
 which will make it more likely to predict longer idle durations going
 forward, but that will also cause deeper idle states to be selected
 going forward, on average, which is what's needed here.]

Fixes: 87c9fe6ee495 (cpuidle: menu: Avoid selecting shallow states with stopped tick)
Reported-by: Leo Yan 
Cc: 4.17+  # 4.17+: 5ef499cd571c (cpuidle: menu: Handle ...)
Signed-off-by: Rafael J. Wysocki

Merge tag 'pm-4.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2018-08-22T14:42:36+00:00

Pull more power management updates from Rafael Wysocki:
 "These fix the main idle loop and the menu cpuidle governor, clean up
  the latter, fix a mistake in the PCI bus type's support for system
  suspend and resume, fix the ondemand and conservative cpufreq
  governors, address a build issue in the system wakeup framework and
  make the ACPI C-states desciptions less confusing.

  Specifics:

   - Make the idle loop handle stopped scheduler tick correctly (Rafael
     Wysocki).

   - Prevent the menu cpuidle governor from letting CPUs spend too much
     time in shallow idle states when it is invoked with scheduler tick
     stopped and clean it up somewhat (Rafael Wysocki).

   - Avoid invoking the platform firmware to make the platform enter the
     ACPI S3 sleep state with suspended PCIe root ports which may
     confuse the firmware and cause it to crash (Rafael Wysocki).

   - Fix sysfs-related race in the ondemand and conservative cpufreq
     governors which may cause the system to crash if the governor
     module is removed during an update of CPU frequency limits (Henry
     Willard).

   - Select SRCU when building the system wakeup framework to avoid a
     build issue in it (zhangyi).

   - Make the descriptions of ACPI C-states vendor-neutral to avoid
     confusion (Prarit Bhargava)"

* tag 'pm-4.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: menu: Handle stopped tick more aggressively
  sched: idle: Avoid retaining the tick when it has been stopped
  PCI / ACPI / PM: Resume all bridges on suspend-to-RAM
  cpuidle: menu: Update stale polling override comment
  cpufreq: governor: Avoid accessing invalid governor_data
  x86/ACPI/cstate: Make APCI C1 FFH MWAIT C-state description vendor-neutral
  cpuidle: menu: Fix white space
  PM / sleep: wakeup: Fix build error caused by missing SRCU support

cpuidle: menu: Handle stopped tick more aggressively

2018-08-20T11:37:03+00:00

Commit 87c9fe6ee495 (cpuidle: menu: Avoid selecting shallow states
with stopped tick) missed the case when the target residencies of
deep idle states of CPUs are above the tick boundary which may cause
the CPU to get stuck in a shallow idle state for a long time.

Say there are two CPU idle states available: one shallow, with the
target residency much below the tick boundary and one deep, with
the target residency significantly above the tick boundary.  In
that case, if the tick has been stopped already and the expected
next timer event is relatively far in the future, the governor will
assume the idle duration to be equal to TICK_USEC and it will select
the idle state for the CPU accordingly.  However, that will cause the
shallow state to be selected even though it would have been more
energy-efficient to select the deep one.

To address this issue, modify the governor to always use the time
till the closest timer event instead of the predicted idle duration
if the latter is less than the tick period length and the tick has
been stopped already.  Also make it extend the search for a matching
idle state if the tick is stopped to avoid settling on a shallow
state if deep states with target residencies above the tick period
length are available.

In addition, make it always indicate that the tick should be stopped
if it has been stopped already for consistency.

Fixes: 87c9fe6ee495 (cpuidle: menu: Avoid selecting shallow states with stopped tick)
Reported-by: Leo Yan 
Acked-by: Peter Zijlstra (Intel) 
Cc: 4.17+  # 4.17+
Signed-off-by: Rafael J. Wysocki