linux-stable.git/kernel/rcu/tree.c, branch linux-5.11.y Linux kernel stable tree rcu: Remove spurious instrumentation_end() in rcu_nmi_enter() 2021-05-14T08:49:52+00:00 Zhouyi Zhou zhouzhouyi@gmail.com 2021-01-11T01:08:59+00:00 6d79181f4e28ce9f058247dc5e18b1b5f1b74c83 [ Upstream commit 6494ccb93271bee596a12db32ff44867d5be2321 ] In rcu_nmi_enter(), there is an erroneous instrumentation_end() in the second branch of the "if" statement. Oddly enough, "objtool check -f vmlinux.o" fails to complain because it is unable to correctly cover all cases. Instead, objtool visits the third branch first, which marks following trace_rcu_dyntick() as visited. This commit therefore removes the spurious instrumentation_end(). Fixes: 04b25a495bd6 ("rcu: Mark rcu_nmi_enter() call to rcu_cleanup_after_idle() noinstr") Reported-by Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6494ccb93271bee596a12db32ff44867d5be2321 ]

In rcu_nmi_enter(), there is an erroneous instrumentation_end() in the
second branch of the "if" statement.  Oddly enough, "objtool check -f
vmlinux.o" fails to complain because it is unable to correctly cover
all cases.  Instead, objtool visits the third branch first, which marks
following trace_rcu_dyntick() as visited.  This commit therefore removes
the spurious instrumentation_end().

Fixes: 04b25a495bd6 ("rcu: Mark rcu_nmi_enter() call to rcu_cleanup_after_idle() noinstr")
Reported-by Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
kvfree_rcu: Use same set of GFP flags as does single-argument 2021-05-12T06:37:21+00:00 Uladzislau Rezki (Sony) urezki@gmail.com 2021-01-29T20:05:05+00:00 21f38bcbde96d861ba9a272f156e742483e7c194 [ Upstream commit ee6ddf58475cce8a3d3697614679cd8cb4a6f583 ] Running an rcuscale stress-suite can lead to "Out of memory" of a system. This can happen under high memory pressure with a small amount of physical memory. For example, a KVM test configuration with 64 CPUs and 512 megabytes can result in OOM when running rcuscale with below parameters: ../kvm.sh --torture rcuscale --allcpus --duration 10 --kconfig CONFIG_NR_CPUS=64 \ --bootargs "rcuscale.kfree_rcu_test=1 rcuscale.kfree_nthreads=16 rcuscale.holdoff=20 \ rcuscale.kfree_loops=10000 torture.disable_onoff_at_boot" --trust-make <snip> [ 12.054448] kworker/1:1H invoked oom-killer: gfp_mask=0x2cc0(GFP_KERNEL|__GFP_NOWARN), order=0, oom_score_adj=0 [ 12.055303] CPU: 1 PID: 377 Comm: kworker/1:1H Not tainted 5.11.0-rc3+ #510 [ 12.055416] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014 [ 12.056485] Workqueue: events_highpri fill_page_cache_func [ 12.056485] Call Trace: [ 12.056485] dump_stack+0x57/0x6a [ 12.056485] dump_header+0x4c/0x30a [ 12.056485] ? del_timer_sync+0x20/0x30 [ 12.056485] out_of_memory.cold.47+0xa/0x7e [ 12.056485] __alloc_pages_slowpath.constprop.123+0x82f/0xc00 [ 12.056485] __alloc_pages_nodemask+0x289/0x2c0 [ 12.056485] __get_free_pages+0x8/0x30 [ 12.056485] fill_page_cache_func+0x39/0xb0 [ 12.056485] process_one_work+0x1ed/0x3b0 [ 12.056485] ? process_one_work+0x3b0/0x3b0 [ 12.060485] worker_thread+0x28/0x3c0 [ 12.060485] ? process_one_work+0x3b0/0x3b0 [ 12.060485] kthread+0x138/0x160 [ 12.060485] ? kthread_park+0x80/0x80 [ 12.060485] ret_from_fork+0x22/0x30 [ 12.062156] Mem-Info: [ 12.062350] active_anon:0 inactive_anon:0 isolated_anon:0 [ 12.062350] active_file:0 inactive_file:0 isolated_file:0 [ 12.062350] unevictable:0 dirty:0 writeback:0 [ 12.062350] slab_reclaimable:2797 slab_unreclaimable:80920 [ 12.062350] mapped:1 shmem:2 pagetables:8 bounce:0 [ 12.062350] free:10488 free_pcp:1227 free_cma:0 ... [ 12.101610] Out of memory and no killable processes... [ 12.102042] Kernel panic - not syncing: System is deadlocked on memory [ 12.102583] CPU: 1 PID: 377 Comm: kworker/1:1H Not tainted 5.11.0-rc3+ #510 [ 12.102600] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014 <snip> Because kvfree_rcu() has a fallback path, memory allocation failure is not the end of the world. Furthermore, the added overhead of aggressive GFP settings must be balanced against the overhead of the fallback path, which is a cache miss for double-argument kvfree_rcu() and a call to synchronize_rcu() for single-argument kvfree_rcu(). The current choice of GFP_KERNEL|__GFP_NOWARN can result in longer latencies than a call to synchronize_rcu(), so less-tenacious GFP flags would be helpful. Here is the tradeoff that must be balanced: a) Minimize use of the fallback path, b) Avoid pushing the system into OOM, c) Bound allocation latency to that of synchronize_rcu(), and d) Leave the emergency reserves to use cases lacking fallbacks. This commit therefore changes GFP flags from GFP_KERNEL|__GFP_NOWARN to GFP_KERNEL|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_NOWARN. This combination leaves the emergency reserves alone and can initiate reclaim, but will not invoke the OOM killer. Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ee6ddf58475cce8a3d3697614679cd8cb4a6f583 ]

Running an rcuscale stress-suite can lead to "Out of memory" of a
system. This can happen under high memory pressure with a small amount
of physical memory.

For example, a KVM test configuration with 64 CPUs and 512 megabytes
can result in OOM when running rcuscale with below parameters:

../kvm.sh --torture rcuscale --allcpus --duration 10 --kconfig CONFIG_NR_CPUS=64 \
--bootargs "rcuscale.kfree_rcu_test=1 rcuscale.kfree_nthreads=16 rcuscale.holdoff=20 \
  rcuscale.kfree_loops=10000 torture.disable_onoff_at_boot" --trust-make

<snip>
[   12.054448] kworker/1:1H invoked oom-killer: gfp_mask=0x2cc0(GFP_KERNEL|__GFP_NOWARN), order=0, oom_score_adj=0
[   12.055303] CPU: 1 PID: 377 Comm: kworker/1:1H Not tainted 5.11.0-rc3+ #510
[   12.055416] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014
[   12.056485] Workqueue: events_highpri fill_page_cache_func
[   12.056485] Call Trace:
[   12.056485]  dump_stack+0x57/0x6a
[   12.056485]  dump_header+0x4c/0x30a
[   12.056485]  ? del_timer_sync+0x20/0x30
[   12.056485]  out_of_memory.cold.47+0xa/0x7e
[   12.056485]  __alloc_pages_slowpath.constprop.123+0x82f/0xc00
[   12.056485]  __alloc_pages_nodemask+0x289/0x2c0
[   12.056485]  __get_free_pages+0x8/0x30
[   12.056485]  fill_page_cache_func+0x39/0xb0
[   12.056485]  process_one_work+0x1ed/0x3b0
[   12.056485]  ? process_one_work+0x3b0/0x3b0
[   12.060485]  worker_thread+0x28/0x3c0
[   12.060485]  ? process_one_work+0x3b0/0x3b0
[   12.060485]  kthread+0x138/0x160
[   12.060485]  ? kthread_park+0x80/0x80
[   12.060485]  ret_from_fork+0x22/0x30
[   12.062156] Mem-Info:
[   12.062350] active_anon:0 inactive_anon:0 isolated_anon:0
[   12.062350]  active_file:0 inactive_file:0 isolated_file:0
[   12.062350]  unevictable:0 dirty:0 writeback:0
[   12.062350]  slab_reclaimable:2797 slab_unreclaimable:80920
[   12.062350]  mapped:1 shmem:2 pagetables:8 bounce:0
[   12.062350]  free:10488 free_pcp:1227 free_cma:0
...
[   12.101610] Out of memory and no killable processes...
[   12.102042] Kernel panic - not syncing: System is deadlocked on memory
[   12.102583] CPU: 1 PID: 377 Comm: kworker/1:1H Not tainted 5.11.0-rc3+ #510
[   12.102600] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014
<snip>

Because kvfree_rcu() has a fallback path, memory allocation failure is
not the end of the world.  Furthermore, the added overhead of aggressive
GFP settings must be balanced against the overhead of the fallback path,
which is a cache miss for double-argument kvfree_rcu() and a call to
synchronize_rcu() for single-argument kvfree_rcu().  The current choice
of GFP_KERNEL|__GFP_NOWARN can result in longer latencies than a call
to synchronize_rcu(), so less-tenacious GFP flags would be helpful.

Here is the tradeoff that must be balanced:
    a) Minimize use of the fallback path,
    b) Avoid pushing the system into OOM,
    c) Bound allocation latency to that of synchronize_rcu(), and
    d) Leave the emergency reserves to use cases lacking fallbacks.

This commit therefore changes GFP flags from GFP_KERNEL|__GFP_NOWARN to
GFP_KERNEL|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_NOWARN.  This combination
leaves the emergency reserves alone and can initiate reclaim, but will
not invoke the OOM killer.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point 2021-03-04T11:15:31+00:00 Frederic Weisbecker frederic@kernel.org 2021-01-31T23:05:48+00:00 4d5fe992200b63342a42893862ee09af55c254ca commit 4ae7dc97f726ea95c58ac58af71cc034ad22d7de upstream. Following the idle loop model, cleanly check for pending rcuog wakeup before the last rescheduling point upon resuming to guest mode. This way we can avoid to do it from rcu_user_enter() with the last resort self-IPI hack that enforces rescheduling. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-6-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4ae7dc97f726ea95c58ac58af71cc034ad22d7de upstream.

Following the idle loop model, cleanly check for pending rcuog wakeup
before the last rescheduling point upon resuming to guest mode. This
way we can avoid to do it from rcu_user_enter() with the last resort
self-IPI hack that enforces rescheduling.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210131230548.32970-6-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
entry: Explicitly flush pending rcuog wakeup before last rescheduling point 2021-03-04T11:15:31+00:00 Frederic Weisbecker frederic@kernel.org 2021-01-31T23:05:47+00:00 e868ddb4381e3b1d24860a040e552fe9a5cf26dc commit 47b8ff194c1fd73d58dc339b597d466fe48c8958 upstream. Following the idle loop model, cleanly check for pending rcuog wakeup before the last rescheduling point on resuming to user mode. This way we can avoid to do it from rcu_user_enter() with the last resort self-IPI hack that enforces rescheduling. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-5-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 47b8ff194c1fd73d58dc339b597d466fe48c8958 upstream.

Following the idle loop model, cleanly check for pending rcuog wakeup
before the last rescheduling point on resuming to user mode. This
way we can avoid to do it from rcu_user_enter() with the last resort
self-IPI hack that enforces rescheduling.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210131230548.32970-5-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rcu/nocb: Trigger self-IPI on late deferred wake up before user resume 2021-03-04T11:15:31+00:00 Frederic Weisbecker frederic@kernel.org 2021-01-31T23:05:46+00:00 23e600cc996fb66a2f99550d6d730b051d379dc6 commit f8bb5cae9616224a39cbb399de382d36ac41df10 upstream. Entering RCU idle mode may cause a deferred wake up of an RCU NOCB_GP kthread (rcuog) to be serviced. Unfortunately the call to rcu_user_enter() is already past the last rescheduling opportunity before we resume to userspace or to guest mode. We may escape there with the woken task ignored. The ultimate resort to fix every callsites is to trigger a self-IPI (nohz_full depends on arch to implement arch_irq_work_raise()) that will trigger a reschedule on IRQ tail or guest exit. Eventually every site that want a saner treatment will need to carefully place a call to rcu_nocb_flush_deferred_wakeup() before the last explicit need_resched() check upon resume. Fixes: 96d3fd0d315a (rcu: Break call_rcu() deadlock involving scheduler and perf) Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-4-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f8bb5cae9616224a39cbb399de382d36ac41df10 upstream.

Entering RCU idle mode may cause a deferred wake up of an RCU NOCB_GP
kthread (rcuog) to be serviced.

Unfortunately the call to rcu_user_enter() is already past the last
rescheduling opportunity before we resume to userspace or to guest mode.
We may escape there with the woken task ignored.

The ultimate resort to fix every callsites is to trigger a self-IPI
(nohz_full depends on arch to implement arch_irq_work_raise()) that will
trigger a reschedule on IRQ tail or guest exit.

Eventually every site that want a saner treatment will need to carefully
place a call to rcu_nocb_flush_deferred_wakeup() before the last explicit
need_resched() check upon resume.

Fixes: 96d3fd0d315a (rcu: Break call_rcu() deadlock involving scheduler and perf)
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210131230548.32970-4-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rcu/nocb: Perform deferred wake up before last idle's need_resched() check 2021-03-04T11:15:31+00:00 Frederic Weisbecker frederic@kernel.org 2021-01-31T23:05:45+00:00 3b7f1cc4be2bf8c192b5bc89c1ad697df061aa4b commit 43789ef3f7d61aa7bed0cb2764e588fc990c30ef upstream. Entering RCU idle mode may cause a deferred wake up of an RCU NOCB_GP kthread (rcuog) to be serviced. Usually a local wake up happening while running the idle task is handled in one of the need_resched() checks carefully placed within the idle loop that can break to the scheduler. Unfortunately the call to rcu_idle_enter() is already beyond the last generic need_resched() check and we may halt the CPU with a resched request unhandled, leaving the task hanging. Fix this with splitting the rcuog wakeup handling from rcu_idle_enter() and place it before the last generic need_resched() check in the idle loop. It is then assumed that no call to call_rcu() will be performed after that in the idle loop until the CPU is put in low power mode. Fixes: 96d3fd0d315a (rcu: Break call_rcu() deadlock involving scheduler and perf) Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-3-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 43789ef3f7d61aa7bed0cb2764e588fc990c30ef upstream.

Entering RCU idle mode may cause a deferred wake up of an RCU NOCB_GP
kthread (rcuog) to be serviced.

Usually a local wake up happening while running the idle task is handled
in one of the need_resched() checks carefully placed within the idle
loop that can break to the scheduler.

Unfortunately the call to rcu_idle_enter() is already beyond the last
generic need_resched() check and we may halt the CPU with a resched
request unhandled, leaving the task hanging.

Fix this with splitting the rcuog wakeup handling from rcu_idle_enter()
and place it before the last generic need_resched() check in the idle
loop. It is then assumed that no call to call_rcu() will be performed
after that in the idle loop until the CPU is put in low power mode.

Fixes: 96d3fd0d315a (rcu: Break call_rcu() deadlock involving scheduler and perf)
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210131230548.32970-3-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers 2021-03-04T11:15:31+00:00 Frederic Weisbecker frederic@kernel.org 2021-01-31T23:05:44+00:00 487e35b007b33dcb33366b4857a4f55772f5274e commit 54b7429efffc99e845ba9381bee3244f012a06c2 upstream. Deferred wakeup of rcuog kthreads upon RCU idle mode entry is going to be handled differently whether initiated by idle, user or guest. Prepare with pulling that control up to rcu_eqs_enter() callers. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-2-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 54b7429efffc99e845ba9381bee3244f012a06c2 upstream.

Deferred wakeup of rcuog kthreads upon RCU idle mode entry is going to
be handled differently whether initiated by idle, user or guest. Prepare
with pulling that control up to rcu_eqs_enter() callers.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210131230548.32970-2-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge tag 'sched-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-12-15T02:29:11+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-15T02:29:11+00:00 adb35e8dc98ba9bda99ff79ac6a05b8fcde2a762 Pull scheduler updates from Thomas Gleixner: - migrate_disable/enable() support which originates from the RT tree and is now a prerequisite for the new preemptible kmap_local() API which aims to replace kmap_atomic(). - A fair amount of topology and NUMA related improvements - Improvements for the frequency invariant calculations - Enhanced robustness for the global CPU priority tracking and decision making - The usual small fixes and enhancements all over the place * tag 'sched-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits) sched/fair: Trivial correction of the newidle_balance() comment sched/fair: Clear SMT siblings after determining the core is not idle sched: Fix kernel-doc markup x86: Print ratio freq_max/freq_base used in frequency invariance calculations x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC x86, sched: Calculate frequency invariance for AMD systems irq_work: Optimize irq_work_single() smp: Cleanup smp_call_function*() irq_work: Cleanup sched: Limit the amount of NUMA imbalance that can exist at fork time sched/numa: Allow a floating imbalance between NUMA nodes sched: Avoid unnecessary calculation of load imbalance at clone time sched/numa: Rename nr_running and break out the magic number sched: Make migrate_disable/enable() independent of RT sched/topology: Condition EAS enablement on FIE support arm64: Rebuild sched domains on invariance status changes sched/topology,schedutil: Wrap sched domains rebuild sched/uclamp: Allow to reset a task uclamp constraint value sched/core: Fix typos in comments Documentation: scheduler: fix information on arch SD flags, sched_domain and sched_debug ... 
Pull scheduler updates from Thomas Gleixner:

 - migrate_disable/enable() support which originates from the RT tree
   and is now a prerequisite for the new preemptible kmap_local() API
   which aims to replace kmap_atomic().

 - A fair amount of topology and NUMA related improvements

 - Improvements for the frequency invariant calculations

 - Enhanced robustness for the global CPU priority tracking and decision
   making

 - The usual small fixes and enhancements all over the place

* tag 'sched-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits)
  sched/fair: Trivial correction of the newidle_balance() comment
  sched/fair: Clear SMT siblings after determining the core is not idle
  sched: Fix kernel-doc markup
  x86: Print ratio freq_max/freq_base used in frequency invariance calculations
  x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC
  x86, sched: Calculate frequency invariance for AMD systems
  irq_work: Optimize irq_work_single()
  smp: Cleanup smp_call_function*()
  irq_work: Cleanup
  sched: Limit the amount of NUMA imbalance that can exist at fork time
  sched/numa: Allow a floating imbalance between NUMA nodes
  sched: Avoid unnecessary calculation of load imbalance at clone time
  sched/numa: Rename nr_running and break out the magic number
  sched: Make migrate_disable/enable() independent of RT
  sched/topology: Condition EAS enablement on FIE support
  arm64: Rebuild sched domains on invariance status changes
  sched/topology,schedutil: Wrap sched domains rebuild
  sched/uclamp: Allow to reset a task uclamp constraint value
  sched/core: Fix typos in comments
  Documentation: scheduler: fix information on arch SD flags, sched_domain and sched_debug
  ...
Merge tag 'core-rcu-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-12-15T01:21:16+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-15T01:21:16+00:00 8c1dccc80380fca8db09c2a81f5deb3c49b112b2 Pull RCU updates from Thomas Gleixner: "RCU, LKMM and KCSAN updates collected by Paul McKenney. RCU: - Avoid cpuinfo-induced IPI pileups and idle-CPU IPIs - Lockdep-RCU updates reducing the need for __maybe_unused - Tasks-RCU updates - Miscellaneous fixes - Documentation updates - Torture-test updates KCSAN: - updates for selftests, avoiding setting watchpoints on NULL pointers - fix to watchpoint encoding LKMM: - updates for documentation along with some updates to example-code litmus tests" * tag 'core-rcu-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) srcu: Take early exit on memory-allocation failure rcu/tree: Defer kvfree_rcu() allocation to a clean context rcu: Do not report strict GPs for outgoing CPUs rcu: Fix a typo in rcu_blocking_is_gp() header comment rcu: Prevent lockdep-RCU splats on lock acquisition/release rcu/tree: nocb: Avoid raising softirq for offloaded ready-to-execute CBs rcu,ftrace: Fix ftrace recursion rcu/tree: Make struct kernel_param_ops definitions const rcu/tree: Add a warning if CPU being onlined did not report QS already rcu: Clarify nocb kthreads naming in RCU_NOCB_CPU config rcu: Fix single-CPU check in rcu_blocking_is_gp() rcu: Implement rcu_segcblist_is_offloaded() config dependent list.h: Update comment to explicitly note circular lists rcu: Panic after fixed number of stalls x86/smpboot: Move rcu_cpu_starting() earlier rcu: Allow rcu_irq_enter_check_tick() from NMI tools/memory-model: Label MP tests' producers and consumers tools/memory-model: Use "buf" and "flag" for message-passing tests tools/memory-model: Add types to litmus tests tools/memory-model: Add a glossary of LKMM terms ... 
Pull RCU updates from Thomas Gleixner:
 "RCU, LKMM and KCSAN updates collected by Paul McKenney.

  RCU:
   - Avoid cpuinfo-induced IPI pileups and idle-CPU IPIs

   - Lockdep-RCU updates reducing the need for __maybe_unused

   - Tasks-RCU updates

   - Miscellaneous fixes

   - Documentation updates

   - Torture-test updates

  KCSAN:
   - updates for selftests, avoiding setting watchpoints on NULL pointers

   - fix to watchpoint encoding

  LKMM:
   - updates for documentation along with some updates to example-code
     litmus tests"

* tag 'core-rcu-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  srcu: Take early exit on memory-allocation failure
  rcu/tree: Defer kvfree_rcu() allocation to a clean context
  rcu: Do not report strict GPs for outgoing CPUs
  rcu: Fix a typo in rcu_blocking_is_gp() header comment
  rcu: Prevent lockdep-RCU splats on lock acquisition/release
  rcu/tree: nocb: Avoid raising softirq for offloaded ready-to-execute CBs
  rcu,ftrace: Fix ftrace recursion
  rcu/tree: Make struct kernel_param_ops definitions const
  rcu/tree: Add a warning if CPU being onlined did not report QS already
  rcu: Clarify nocb kthreads naming in RCU_NOCB_CPU config
  rcu: Fix single-CPU check in rcu_blocking_is_gp()
  rcu: Implement rcu_segcblist_is_offloaded() config dependent
  list.h: Update comment to explicitly note circular lists
  rcu: Panic after fixed number of stalls
  x86/smpboot:  Move rcu_cpu_starting() earlier
  rcu: Allow rcu_irq_enter_check_tick() from NMI
  tools/memory-model: Label MP tests' producers and consumers
  tools/memory-model: Use "buf" and "flag" for message-passing tests
  tools/memory-model: Add types to litmus tests
  tools/memory-model: Add a glossary of LKMM terms
  ...
Merge branch 'linus' into sched/core, to resolve semantic conflict 2020-11-27T10:10:50+00:00 Ingo Molnar mingo@kernel.org 2020-11-27T10:09:57+00:00 a787bdaff83a085288b6fc607afb4bb648da3cc9 Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Signed-off-by: Ingo Molnar <mingo@kernel.org>