might_sleep() and smp_processor_id() checks are enabled after the boot
process is done. That hides bugs in the SMP bringup and driver
initialization code.

Enable it right when the scheduler starts working, i.e. when init task and
kthreadd have been created and right before the idle task enables
preemption.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.272225698@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

might_sleep() debugging and smp_processor_id() debugging should be active
right after the scheduler starts working. The init task can invoke
smp_processor_id() from preemptible context as it is pinned on the boot cpu
until sched_smp_init() removes the pinning and lets it schedule on all non
isolated cpus.

Add a new state which allows to enable those checks earlier and add it to
the xen do_poweroff() function.

No functional change.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.196214622@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in kswapd_run() to handle the extra states.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184736.119158930@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in boot_delay_msec() to handle the extra
states.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184736.027534895@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in core_kernel_text() to handle the extra
states, i.e. to cover init text up to the point where the system switches
to state RUNNING.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184735.949992741@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in async_run_entry_fn() and
async_synchronize_cookie_domain() to handle the extra states.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.865155020@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in of_iommu_driver_present() to handle the
extra states.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170516184735.788023442@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state checks in dmar_parse_one_atsr() and
dmar_iommu_notify_scope_dev() to handle the extra states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170516184735.712365947@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in pas_cpufreq_cpu_exit() to handle the extra
states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170516184735.620023128@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

get_nid_for_pfn() checks for system_state == BOOTING to decide whether to
use early_pfn_to_nid() when CONFIG_DEFERRED_STRUCT_PAGE_INIT=y.

That check is dubious, because the switch to state RUNNING happes way after
page_alloc_init_late() has been invoked.

Change the check to less than RUNNING state so it covers the new
intermediate states as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.528279534@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Make the decision whether a pci root is hotplugged depend on SYSTEM_RUNNING
instead of !SYSTEM_BOOTING. It makes no sense to cover states greater than
SYSTEM_RUNNING as there are not hotplug events on reboot and poweroff.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/20170516184735.446455652@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_generic_cpu_bootable() to handle the
extra states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170516184735.359536998@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in stop_this_cpu() to handle the extra states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.283420315@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in announce_cpu() to handle the extra states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184735.191715856@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_send_stop() to handle the extra states.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20170516184735.112589728@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in ipi_cpu_stop() to handle the extra states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20170516184735.020718977@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

Some of the boot code in init_kernel_freeable() which runs before SMP
bringup assumes (rightfully) that it runs on the boot CPU and therefore can
use smp_processor_id() in preemptible context.

That works so far because the smp_processor_id() check starts to be
effective after smp bringup. That's just wrong. Starting with SMP bringup
and the ability to move threads around, smp_processor_id() in preemptible
context is broken.

Aside of that it does not make sense to allow init to run on all CPUs
before sched_smp_init() has been run.

Pin the init to the boot CPU so the existing code can continue to use
smp_processor_id() without triggering the checks when the enabling of those
checks starts earlier.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184734.943149935@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

A customer has reported a soft-lockup when running an intensive
memory stress test, where the trace on multiple CPU's looks like this:

 RIP: 0010:[<ffffffff810c53fe>]
  [<ffffffff810c53fe>] native_queued_spin_lock_slowpath+0x10e/0x190
...
 Call Trace:
  [<ffffffff81182d07>] queued_spin_lock_slowpath+0x7/0xa
  [<ffffffff811bc331>] change_protection_range+0x3b1/0x930
  [<ffffffff811d4be8>] change_prot_numa+0x18/0x30
  [<ffffffff810adefe>] task_numa_work+0x1fe/0x310
  [<ffffffff81098322>] task_work_run+0x72/0x90

Further investigation showed that the lock contention here is pmd_lock().

The task_numa_work() function makes sure that only one thread is let to perform
the work in a single scan period (via cmpxchg), but if there's a thread with
mmap_sem locked for writing for several periods, multiple threads in
task_numa_work() can build up a convoy waiting for mmap_sem for read and then
all get unblocked at once.

This patch changes the down_read() to the trylock version, which prevents the
build up. For a workload experiencing mmap_sem contention, it's probably better
to postpone the NUMA balancing work anyway. This seems to have fixed the soft
lockups involving pmd_lock(), which is in line with the convoy theory.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170515131316.21909-1-vbabka@suse.czSigned-off-by: Ingo Molnar <mingo@kernel.org>

With CONFIG_RT_GROUP_SCHED=y, do_sched_rt_period_timer() sequentially
takes each CPU's rq->lock. On a large, busy system, the cumulative time it
takes to acquire each lock can be excessive, even triggering a watchdog
timeout.

If rt_rq->rt_time and rt_rq->rt_nr_running are both zero, this function does
nothing while holding the lock, so don't bother taking it at all.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a767637b-df85-912f-ba69-c90ee00a3fb6@oracle.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

When priority inheritance was added back in 2.6.18 to sched_setscheduler(), it
added a path to taking an rt-mutex wait_lock, which is not IRQ safe. As PI
is not a common occurrence, lockdep will likely never trigger if
sched_setscheduler was called from interrupt context. A BUG_ON() was added
to trigger if __sched_setscheduler() was ever called from interrupt context
because there was a possibility to take the wait_lock.

Today the wait_lock is irq safe, but the path to taking it in
sched_setscheduler() is the same as the path to taking it from normal
context. The wait_lock is taken with raw_spin_lock_irq() and released with
raw_spin_unlock_irq() which will indiscriminately enable interrupts,
which would be bad in interrupt context.

The problem is that normalize_rt_tasks, which is called by triggering the
sysrq nice-all-RT-tasks was changed to call __sched_setscheduler(), and this
is done from interrupt context!

Now __sched_setscheduler() takes a "pi" parameter that is used to know if
the priority inheritance should be called or not. As the BUG_ON() only cares
about calling the PI code, it should only bug if called from interrupt
context with the "pi" parameter set to true.
Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dbc7f069 ("sched: Use replace normalize_task() with __sched_setscheduler()")
Link: http://lkml.kernel.org/r/20170308124654.10e598f2@gandalf.local.homeSigned-off-by: Ingo Molnar <mingo@kernel.org>

pick_next_pushable_dl_task(rq) has BUG_ON(rq->cpu != task_cpu(task))
when it returns a task other than NULL, which means that task_cpu(task)
must be rq->cpu. So if task == next_task, then task_cpu(next_task) must
be rq->cpu as well. Remove the redundant condition and make the code simpler.

This way one unnecessary branch and two LOAD operations can be avoided.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494551159-22367-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

pick_next_pushable_task(rq) has BUG_ON(rq_cpu != task_cpu(task)) when
it returns a task other than NULL, which means that task_cpu(task) must
be rq->cpu. So if task == next_task, then task_cpu(next_task) must be
rq->cpu as well. Remove the redundant condition and make the code simpler.

This way one unnecessary branch and two LOAD operations can be avoided.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494551143-22219-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Now that we've added llist_for_each_entry_safe(), use it to simplify
an open coded version of it in sched_ttwu_pending().
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494549584-11730-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Sometimes we have to dereference next field of llist node before entering
loop becasue the node might be deleted or the next field might be
modified within the loop. So this adds the safe version of llist_for_each(),
that is, llist_for_each_safe().
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Huang, Ying <ying.huang@intel.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494549416-10539-1-git-send-email-byungchul.park@lge.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The cpumasks in smp_call_function_many() are private and not subject
to concurrency, atomic bitops are pointless and expensive.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Inter-Processor-Interrupt(IPI) is needed when a page is unmapped and the
process' mm_cpumask() shows the process has ever run on other CPUs. page
migration, page reclaim all need IPIs. The number of IPI needed to send
to different CPUs is especially large for multi-threaded workload since
mm_cpumask() is per process.

For smp_call_function_many(), whenever a CPU queues a CSD to a target
CPU, it will send an IPI to let the target CPU to handle the work.
This isn't necessary - we need only send IPI when queueing a CSD
to an empty call_single_queue.

The reason:

flush_smp_call_function_queue() that is called upon a CPU receiving an
IPI will empty the queue and then handle all of the CSDs there. So if
the target CPU's call_single_queue is not empty, we know that:
i.  An IPI for the target CPU has already been sent by 'previous queuers';
ii. flush_smp_call_function_queue() hasn't emptied that CPU's queue yet.
Thus, it's safe for us to just queue our CSD there without sending an
addtional IPI. And for the 'previous queuers', we can limit it to the
first queuer.

To demonstrate the effect of this patch, a multi-thread workload that
spawns 80 threads to equally consume 100G memory is used. This is tested
on a 2 node broadwell-EP which has 44cores/88threads and 32G memory. So
after 32G memory is used up, page reclaiming starts to happen a lot.

With this patch, IPI number dropped 88% and throughput increased about
15% for the above workload.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20170519075331.GE2084@aaronlu.sh.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull crypto fix from Herbert Xu:
 "This fixes a regression in the skcipher interface that allows bogus
  key parameters to hit underlying implementations which can cause
  crashes"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: skcipher - Add missing API setkey checks

Pull pstore fix from Kees Cook:
 "Marta noticed another misbehavior in EFI pstore, which this fixes.

  Hopefully this is the last of the v4.12 fixes for pstore!"

* tag 'pstore-v4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  efi-pstore: Fix write/erase id tracking

Pull ACPI fixes from Rafael Wysocki:
 "These revert a 4.11 change that turned out to be problematic and add a
  .gitignore file.

  Specifics:

   - Revert a 4.11 commit related to the ACPI-based handling of laptop
     lids that made changes incompatible with existing user space stacks
     and broke things there (Lv Zheng).

   - Add .gitignore to the ACPI tools directory (Prarit Bhargava)"

* tag 'acpi-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPI / button: Remove lid_init_state=method mode"
  tools/power/acpi: Add .gitignore file

Pull power management fixes from Rafael Wysocki:
 "These fix RTC wakeup from suspend-to-idle broken recently, fix CPU
  idleness detection condition in the schedutil cpufreq governor, fix a
  cpufreq driver build failure, fix an error code path in the power
  capping framework, clean up the hibernate core and update the
  intel_pstate documentation.

  Specifics:

   - Fix RTC wakeup from suspend-to-idle broken by the recent rework of
     ACPI wakeup handling (Rafael Wysocki).

   - Update intel_pstate driver documentation to reflect the current
     code and explain how it works in more detail (Rafael Wysocki).

   - Fix an issue related to CPU idleness detection on systems with
     shared cpufreq policies in the schedutil governor (Juri Lelli).

   - Fix a possible build issue in the dbx500 cpufreq driver (Arnd
     Bergmann).

   - Fix a function in the power capping framework core to return an
     error code instead of 0 when there's an error (Dan Carpenter).

   - Clean up variable definition in the hibernation core (Pushkar
     Jambhlekar)"

* tag 'pm-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: dbx500: add a Kconfig symbol
  PM / hibernate: Declare variables as static
  PowerCap: Fix an error code in powercap_register_zone()
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()
  cpufreq: intel_pstate: Document the current behavior and user interface
  cpufreq: schedutil: use now as reference when aggregating shared policy requests

We need to initializes those variables to 0 for platforms that do not
provide ACPI parameters. Otherwise, we set sda_hold_time to random
values, breaking e.g. Galileo and IOT2000 boards.
Reported-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Fixes: 9d640843 ("i2c: designware: don't infer timings described by ACPI from clock rate")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Prior to the pstore interface refactoring, the "id" generated during
a backend pstore_write() was only retained by the internal pstore
inode tracking list. Additionally the "part" was ignored, so EFI
would encode this in the id. This corrects the misunderstandings
and correctly sets "id" during pstore_write(), and uses "part"
directly during pstore_erase().
Reported-by: Marta Lofstedt <marta.lofstedt@intel.com>
Fixes: 76cc9580 ("pstore: Replace arguments for write() API")
Fixes: a61072aa ("pstore: Replace arguments for erase() API")
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Marta Lofstedt <marta.lofstedt@intel.com>

Pull networking fixes from David Miller:
 "Mostly netfilter bug fixes in here, but we have some bits elsewhere as
  well.

   1) Don't do SNAT replies for non-NATed connections in IPVS, from
      Julian Anastasov.

   2) Don't delete conntrack helpers while they are still in use, from
      Liping Zhang.

   3) Fix zero padding in xtables's xt_data_to_user(), from Willem de
      Bruijn.

   4) Add proper RCU protection to nf_tables_dump_set() because we
      cannot guarantee that we hold the NFNL_SUBSYS_NFTABLES lock. From
      Liping Zhang.

   5) Initialize rcv_mss in tcp_disconnect(), from Wei Wang.

   6) smsc95xx devices can't handle IPV6 checksums fully, so don't
      advertise support for offloading them. From Nisar Sayed.

   7) Fix out-of-bounds access in __ip6_append_data(), from Eric
      Dumazet.

   8) Make atl2_probe() propagate the error code properly on failures,
      from Alexey Khoroshilov.

   9) arp_target[] in bond_check_params() is used uninitialized. This
      got changes from a global static to a local variable, which is how
      this mistake happened. Fix from Jarod Wilson.

  10) Fix fallout from unnecessary NULL check removal in cls_matchall,
      from Jiri Pirko. This is definitely brown paper bag territory..."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  net: sched: cls_matchall: fix null pointer dereference
  vsock: use new wait API for vsock_stream_sendmsg()
  bonding: fix randomly populated arp target array
  net: Make IP alignment calulations clearer.
  bonding: fix accounting of active ports in 3ad
  net: atheros: atl2: don't return zero on failure path in atl2_probe()
  ipv6: fix out of bound writes in __ip6_append_data()
  bridge: start hello_timer when enabling KERNEL_STP in br_stp_start
  smsc95xx: Support only IPv4 TCP/UDP csum offload
  arp: always override existing neigh entries with gratuitous ARP
  arp: postpone addr_type calculation to as late as possible
  arp: decompose is_garp logic into a separate function
  arp: fixed error in a comment
  tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0
  netfilter: xtables: fix build failure from COMPAT_XT_ALIGN outside CONFIG_COMPAT
  ebtables: arpreply: Add the standard target sanity check
  netfilter: nf_tables: revisit chain/object refcounting from elements
  netfilter: nf_tables: missing sanitization in data from userspace
  netfilter: nf_tables: can't assume lock is acquired when dumping set elems
  netfilter: synproxy: fix conntrackd interaction
  ...

Since the head is guaranteed by the check above to be null, the call_rcu
would explode. Remove the previously logically dead code that was made
logically very much alive and kicking.

Fixes: 985538ee ("net/sched: remove redundant null check on head")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As reported by Michal, vsock_stream_sendmsg() could still
sleep at vsock_stream_has_space() after prepare_to_wait():

  vsock_stream_has_space
    vmci_transport_stream_has_space
      vmci_qpair_produce_free_space
        qp_lock
          qp_acquire_queue_mutex
            mutex_lock

Just switch to the new wait API like we did for commit
d9dc8b0f ("net: fix sleeping for sk_wait_event()").
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In commit dc9c4d0f, the arp_target array moved from a static global
to a local variable. By the nature of static globals, the array used to
be initialized to all 0. At present, it's full of random data, which
that gets interpreted as arp_target values, when none have actually been
specified. Systems end up booting with spew along these lines:

[   32.161783] IPv6: ADDRCONF(NETDEV_UP): lacp0: link is not ready
[   32.168475] IPv6: ADDRCONF(NETDEV_UP): lacp0: link is not ready
[   32.175089] 8021q: adding VLAN 0 to HW filter on device lacp0
[   32.193091] IPv6: ADDRCONF(NETDEV_UP): lacp0: link is not ready
[   32.204892] lacp0: Setting MII monitoring interval to 100
[   32.211071] lacp0: Removing ARP target 216.124.228.17
[   32.216824] lacp0: Removing ARP target 218.160.255.255
[   32.222646] lacp0: Removing ARP target 185.170.136.184
[   32.228496] lacp0: invalid ARP target 255.255.255.255 specified for removal
[   32.236294] lacp0: option arp_ip_target: invalid value (-255.255.255.255)
[   32.243987] lacp0: Removing ARP target 56.125.228.17
[   32.249625] lacp0: Removing ARP target 218.160.255.255
[   32.255432] lacp0: Removing ARP target 15.157.233.184
[   32.261165] lacp0: invalid ARP target 255.255.255.255 specified for removal
[   32.268939] lacp0: option arp_ip_target: invalid value (-255.255.255.255)
[   32.276632] lacp0: Removing ARP target 16.0.0.0
[   32.281755] lacp0: Removing ARP target 218.160.255.255
[   32.287567] lacp0: Removing ARP target 72.125.228.17
[   32.293165] lacp0: Removing ARP target 218.160.255.255
[   32.298970] lacp0: Removing ARP target 8.125.228.17
[   32.304458] lacp0: Removing ARP target 218.160.255.255

None of these were actually specified as ARP targets, and the driver does
seem to clean up the mess okay, but it's rather noisy and confusing, leaks
values to userspace, and the 255.255.255.255 spew shows up even when debug
prints are disabled.

The fix: just zero out arp_target at init time.

While we're in here, init arp_all_targets_value in the right place.

Fixes: dc9c4d0f ("bonding: reduce scope of some global variables")
CC: Mahesh Bandewar <maheshb@google.com>
CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: netdev@vger.kernel.org
CC: stable@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

* pm-sleep:
  PM / hibernate: Declare variables as static
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()

* powercap:
  PowerCap: Fix an error code in powercap_register_zone()

* acpi-button:
  Revert "ACPI / button: Remove lid_init_state=method mode"

* acpi-tools:
  tools/power/acpi: Add .gitignore file

* intel_pstate:
  cpufreq: intel_pstate: Document the current behavior and user interface

* pm-cpufreq:
  cpufreq: dbx500: add a Kconfig symbol

* pm-cpufreq-sched:
  cpufreq: schedutil: use now as reference when aggregating shared policy requests