linux-stable.git/drivers/cpuidle, branch v4.19.321

sched,idle,rcu: Push rcu_idle deeper into the idle path

2023-10-25T09:16:26+00:00

commit 1098582a0f6c4e8fd28da0a6305f9233d02c9c1d upstream.

Lots of things take locks, due to a wee bug, rcu_lockdep didn't notice
that the locking tracepoints were using RCU.

Push rcu_idle_{enter,exit}() as deep as possible into the idle paths,
this also resolves a lot of _rcuidle()/RCU_NONIDLE() usage.

Specifically, sched_clock_idle_wakeup_event() will use ktime which
will use seqlocks which will tickle lockdep, and
stop_critical_timings() uses lock.

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/20200821085348.310943801@infradead.org
Tested-by: Linux Kernel Functional Testing 
Tested-by: Naresh Kamboju 
Signed-off-by: Greg Kroah-Hartman

cpuidle: dt: Return the correct numbers of parsed idle states

2023-01-18T10:30:04+00:00

[ Upstream commit ee3c2c8ad6ba6785f14a60e4081d7c82e88162a2 ]

While we correctly skips to initialize an idle state from a disabled idle
state node in DT, the returned value from dt_init_idle_driver() don't get
adjusted accordingly. Instead the number of found idle state nodes are
returned, while the callers are expecting the number of successfully
initialized idle states from DT.

This leads to cpuidle drivers unnecessarily continues to initialize their
idle state specific data. Moreover, in the case when all idle states have
been disabled in DT, we would end up registering a cpuidle driver, rather
than relying on the default arch specific idle call.

Fixes: 9f14da345599 ("drivers: cpuidle: implement DT based idle states infrastructure")
Signed-off-by: Ulf Hansson 
Reviewed-by: Sudeep Holla 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

cpuidle: Fix kobject memory leaks in error paths

2021-11-26T10:36:08+00:00

[ Upstream commit e5f5a66c9aa9c331da5527c2e3fd9394e7091e01 ]

Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
fixes the cleanup of kobjects; however, it removes kfree() calls
altogether, leading to memory leaks.

Fix those and also defer the initialization of dev->kobj_dev until
after the error check, so that we do not end up with a dangling
pointer.

Fixes: c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
Signed-off-by: Anel Orazgaliyeva 
Suggested-by: Aman Priyadarshi 
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

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