user/sven/linux.git/kernel/cpu.c, branch v4.8.10

timers/core: Correct callback order during CPU hot plug

2016-07-28T16:56:22Z

On the tear-down path, the dead CPU callback for the timers was misplaced within the 'cpuhp_state' enumeration. There is a hidden dependency between the timers and block multiqueue. The timers callback must happen before the block multiqueue callback otherwise a RCU stall occurs. Move the timers callback to the proper place in the state machine. Reported-and-tested-by: Jon Hunter Reported-by: kbuild test robot Fixes: 24f73b99716a ("timers/core: Convert to hotplug state machine") Signed-off-by: Richard Cochran Cc: Peter Zijlstra Cc: Sebastian Andrzej Siewior Cc: Rasmus Villemoes Cc: John Stultz Cc: rt@linutronix.de Cc: Oleg Nesterov Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1469610498-25914-1-git-send-email-rcochran@linutronix.de Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

rcu: Convert rcutree to hotplug state machine

2016-07-15T08:41:44Z

Straight forward conversion to the state machine. Though the question arises whether this needs really all these state transitions to work. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.982013161@linutronix.de Signed-off-by: Ingo Molnar

smp/cfd: Convert core to hotplug state machine

2016-07-15T08:41:43Z

Install the callbacks via the state machine. They are installed at runtime so smpcfd_prepare_cpu() needs to be invoked by the boot-CPU. Signed-off-by: Richard Weinberger [ Added the dropped CPU dying case back in. ] Signed-off-by: Richard Cochran Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: Davidlohr Bueso Cc: Linus Torvalds Cc: Mel Gorman Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Thomas Gleixner Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.818376366@linutronix.de Signed-off-by: Ingo Molnar

timers/core: Convert to hotplug state machine

2016-07-15T08:41:42Z

When tearing down, call timers_dead_cpu() before notify_dead(). There is a hidden dependency between: - timers - block multiqueue - rcutree If timers_dead_cpu() comes later than blk_mq_queue_reinit_notify() that latter function causes a RCU stall. Signed-off-by: Richard Cochran Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: John Stultz Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Thomas Gleixner Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.566790058@linutronix.de Signed-off-by: Ingo Molnar

hrtimer: Convert to hotplug state machine

2016-07-15T08:41:37Z

Split out the clockevents callbacks instead of piggybacking them on hrtimers. This gets rid of a POST_DEAD user. See commit: 54e88fad223c ("sched: Make sure timers have migrated before killing the migration_thread") We just move the callback state to the proper place in the state machine. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Rusty Russell Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.485419196@linutronix.de Signed-off-by: Ingo Molnar

workqueue: Convert to state machine callbacks

2016-07-14T07:34:43Z

Get rid of the prio ordering of the separate notifiers and use a proper state callback pair. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Acked-by: Tejun Heo Cc: Andrew Morton Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Nicolas Iooss Cc: Oleg Nesterov Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Rusty Russell Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153335.197083890@linutronix.de Signed-off-by: Ingo Molnar

perf/core: Convert to hotplug state machine

2016-07-14T07:34:31Z

Actually a nice symmetric startup/teardown pair which fits properly into the state machine concept. In the long run we should be able to invoke the startup callback for the boot CPU via the state machine and get rid of the init function which invokes it on the boot CPU. Note: This comes actually before the perf hardware callbacks. In the notifier model the hardware callbacks have a higher priority than the core callback. But that's solely for CPU offline so that hardware migration of events happens before the core is notified about the outgoing CPU. With the symetric state array model we have the following ordering: UP: core -> hardware DOWN: hardware -> core Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Siewior Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153333.587514098@linutronix.de Signed-off-by: Ingo Molnar

cpu/hotplug: Handle early registration gracefully

2016-07-14T07:34:25Z

We switched the hotplug machinery to smpboot threads. Early registration of hotplug callbacks, i.e. from do_pre_smp_initcalls(), happens before the threads are initialized. Instead of moving the thread init, we simply handle it in the hotplug code itself and invoke the function directly. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153332.896450738@linutronix.de Signed-off-by: Ingo Molnar

cpu/hotplug: Keep enough storage space if SMP=n to avoid array out of bounds scribble

2016-07-13T07:29:39Z

Xiaolong Ye reported lock debug warnings triggered by the following commit: 8de4a0066106 ("perf/x86: Convert the core to the hotplug state machine") The bug is the following: the cpuhp_bp_states[] array is cut short when CONFIG_SMP=n, but the dynamically registered callbacks are stored nevertheless and happily scribble outside of the array bounds... We need to store them in case that the state is unregistered so we can invoke the teardown function. That's independent of CONFIG_SMP. Make sure the array is large enough. Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Cc: Adam Borowski Cc: Alexander Shishkin Cc: Anna-Maria Gleixner Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Jiri Olsa Cc: Kan Liang Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Sebastian Andrzej Siewior Cc: Stephane Eranian Cc: Vince Weaver Cc: lkp@01.org Cc: stable@vger.kernel.org Cc: tipbuild@zytor.com Fixes: cff7d378d3fd "cpu/hotplug: Convert to a state machine for the control processor" Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1607122144560.4083@nanos Signed-off-by: Ingo Molnar

sched/hotplug: Make activate() the last hotplug step

2016-05-06T12:58:25Z

The scheduler can handle per cpu threads before the cpu is set to active and it does not allow user space threads on the cpu before active is set. Attaching to the scheduling domains is also not required before user space threads can be handled. Move the activation to the end of the hotplug state space. That also means that deactivation is the first action when a cpu is shut down. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160310120025.597477199@linutronix.de Signed-off-by: Thomas Gleixner