rcu: Update comment from rsp->rcu_gp_seq to rsp->gp_seq

Signed-off-by: Lihao Liang <lihaoliang@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

rcu: Add callbacks-invoked counters

This commit adds a count of the callbacks invoked to the per-CPU rcu_data
structure. This count is printed by the show_rcu_gp_kthreads() that
is invoked by rcuto

rcu: Add callbacks-invoked counters

This commit adds a count of the callbacks invoked to the per-CPU rcu_data
structure. This count is printed by the show_rcu_gp_kthreads() that
is invoked by rcutorture and the RCU CPU stall-warning code. It is also
intended for use by drgn.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next

Some conflicts with ttm_bo->offset removal, but drm-misc-next needs updating to v5.8.

Signed-off-by: Maarten Lankhorst <maarten.la

Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next

Some conflicts with ttm_bo->offset removal, but drm-misc-next needs updating to v5.8.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

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Merge drm/drm-next into drm-intel-next-queued

Catch up with upstream, in particular to get c1e8d7c6a7a6 ("mmap locking
API: convert mmap_sem comments").

Signed-off-by: Jani Nikula <jani.nikula@inte

Merge drm/drm-next into drm-intel-next-queued

Catch up with upstream, in particular to get c1e8d7c6a7a6 ("mmap locking
API: convert mmap_sem comments").

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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Merge tag 'v5.8-rc1' into regulator-5.8

Linux 5.8-rc1

Merge tag 'v5.8-rc1' into fixes

Linux 5.8-rc1

Merge v5.8-rc1 into drm-misc-fixes

Beginning a new release cycles for what will become v5.8. Updating
drm-misc-fixes accordingly.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge branch 'dt/schema-cleanups' into dt/linus

Merge branch 'x86/entry' into ras/core

to fixup conflicts in arch/x86/kernel/cpu/mce/core.c so MCE specific follow
up patches can be applied without creating a horrible merge conflict
afterwards.

Merge branch 'next' into for-linus

Prepare input updates for 5.8 merge window.

Merge tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
"The RCU updates for this cycle were:

- RCU-tasks update, including a

Merge tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
"The RCU updates for this cycle were:

- RCU-tasks update, including addition of RCU Tasks Trace for BPF use
and TASKS_RUDE_RCU

- kfree_rcu() updates.

- Remove scheduler locking restriction

- RCU CPU stall warning updates.

- Torture-test updates.

- Miscellaneous fixes and other updates"

* tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
rcu: Allow for smp_call_function() running callbacks from idle
rcu: Provide rcu_irq_exit_check_preempt()
rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()
rcu: Provide __rcu_is_watching()
rcu: Provide rcu_irq_exit_preempt()
rcu: Make RCU IRQ enter/exit functions rely on in_nmi()
rcu/tree: Mark the idle relevant functions noinstr
x86: Replace ist_enter() with nmi_enter()
x86/mce: Send #MC singal from task work
x86/entry: Get rid of ist_begin/end_non_atomic()
sched,rcu,tracing: Avoid tracing before in_nmi() is correct
sh/ftrace: Move arch_ftrace_nmi_{enter,exit} into nmi exception
lockdep: Always inline lockdep_{off,on}()
hardirq/nmi: Allow nested nmi_enter()
arm64: Prepare arch_nmi_enter() for recursion
printk: Disallow instrumenting print_nmi_enter()
printk: Prepare for nested printk_nmi_enter()
rcutorture: Convert ULONG_CMP_LT() to time_before()
torture: Add a --kasan argument
torture: Save a few lines by using config_override_param initially
...

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Merge branch 'for-5.8' into for-linus

Merge branch 'core/rcu' into sched/core, to pick up dependency

We are going to rely on the loosening of RCU callback semantics,
introduced by this commit:

806f04e9fd2c: ("rcu: Allow for smp_call_

Merge branch 'core/rcu' into sched/core, to pick up dependency

We are going to rely on the loosening of RCU callback semantics,
introduced by this commit:

806f04e9fd2c: ("rcu: Allow for smp_call_function() running callbacks from idle")

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

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Merge branch 'timers/drivers/timer-ti' into timers/drivers/next

Merge tag 'v5.6' into next

Sync up with mainline to get device tree and other changes.

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul McKenney:

1. Miscellaneous fixes.
2. kfree_rcu() updates.

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul McKenney:

1. Miscellaneous fixes.
2. kfree_rcu() updates.
3. Remove scheduler locking restriction
4. RCU-tasks update, including addition of RCU Tasks Trace for
BPF use and RCU Tasks Rude. (This branch is on top of #3 due
to overlap of changed code.)
5. RCU CPU stall warning updates.
6. Torture-test updates.

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Merge branches 'fixes.2020.04.27a', 'kfree_rcu.2020.04.27a', 'rcu-tasks.2020.04.27a', 'stall.2020.04.27a' and 'torture.2020.05.07a' into HEAD

fixes.2020.04.27a: Miscellaneous fixes.
kfree_rcu.2020.

Merge branches 'fixes.2020.04.27a', 'kfree_rcu.2020.04.27a', 'rcu-tasks.2020.04.27a', 'stall.2020.04.27a' and 'torture.2020.05.07a' into HEAD

fixes.2020.04.27a: Miscellaneous fixes.
kfree_rcu.2020.04.27a: Changes related to kfree_rcu().
rcu-tasks.2020.04.27a: Addition of new RCU-tasks flavors.
stall.2020.04.27a: RCU CPU stall-warning updates.
torture.2020.05.07a: Torture-test updates.

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rcu-tasks: Avoid IPIing userspace/idle tasks if kernel is so built

Systems running CPU-bound real-time task do not want IPIs sent to CPUs
executing nohz_full userspace tasks. Battery-powered system

rcu-tasks: Avoid IPIing userspace/idle tasks if kernel is so built

Systems running CPU-bound real-time task do not want IPIs sent to CPUs
executing nohz_full userspace tasks. Battery-powered systems don't
want IPIs sent to idle CPUs in low-power mode. Unfortunately, RCU tasks
trace can and will send such IPIs in some cases.

Both of these situations occur only when the target CPU is in RCU
dyntick-idle mode, in other words, when RCU is not watching the
target CPU. This suggests that CPUs in dyntick-idle mode should use
memory barriers in outermost invocations of rcu_read_lock_trace()
and rcu_read_unlock_trace(), which would allow the RCU tasks trace
grace period to directly read out the target CPU's read-side state.
One challenge is that RCU tasks trace is not targeting a specific
CPU, but rather a task. And that task could switch from one CPU to
another at any time.

This commit therefore uses try_invoke_on_locked_down_task()
and checks for task_curr() in trc_inspect_reader_notrunning().
When this condition holds, the target task is running and cannot move.
If CONFIG_TASKS_TRACE_RCU_READ_MB=y, the new rcu_dynticks_zero_in_eqs()
function can be used to check if the specified integer (in this case,
t->trc_reader_nesting) is zero while the target CPU remains in that same
dyntick-idle sojourn. If so, the target task is in a quiescent state.
If not, trc_read_check_handler() must indicate failure so that the
grace-period kthread can take appropriate action or retry after an
appropriate delay, as the case may be.

With this change, given CONFIG_TASKS_TRACE_RCU_READ_MB=y, if a given
CPU remains idle or a given task continues executing in nohz_full mode,
the RCU tasks trace grace-period kthread will detect this without the
need to send an IPI.

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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rcu: Expedite first two FQS scans under callback-overload conditions

Even if some CPUs have excessive numbers of callbacks, RCU's grace-period
kthread will still wait normally between successive for

rcu: Expedite first two FQS scans under callback-overload conditions

Even if some CPUs have excessive numbers of callbacks, RCU's grace-period
kthread will still wait normally between successive force-quiescent-state
scans. The first two are the most important, as they are the ones that
enlist aid from the scheduler when overloaded. This commit therefore
omits the wait before the first and the second force-quiescent-state
scan under callback-overload conditions.

This approach was inspired by a discussion with Jeff Roberson.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

Pull EFI changes for v5.8 from Ard Biesheuvel:

"- preliminary changes for RISC-V
- add support for setti

Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

Pull EFI changes for v5.8 from Ard Biesheuvel:

"- preliminary changes for RISC-V
- add support for setting the resolution on the EFI framebuffer
- simplify kernel image loading for arm64
- Move .bss into .data via the linker script instead of relying on symbol
annotations.
- Get rid of __pure getters to access global variables
- Clean up the config table matching arrays"

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

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Merge branch 'topic/nhlt' into for-next

Merge NHLT init cleanup.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Merge tag 'tegra-for-5.7-asoc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into asoc-5.7

ASoC: tegra: Fixes for v5.7-rc3

This contains a couple of fixes that are needed to properly

Merge tag 'tegra-for-5.7-asoc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into asoc-5.7

ASoC: tegra: Fixes for v5.7-rc3

This contains a couple of fixes that are needed to properly reconfigure
the audio clocks on older Tegra devices.

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Merge branch 'fixes-v5.7' into fixes

Merge drm/drm-next into drm-misc-next

Backmerging required to pull topic/phy-compliance.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-next into drm-intel-next-queued

Backmerging in order to pull "topic/phy-compliance".

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>