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From: Joel Fernandes <joel@joelfernandes.org>
To: paulmck@kernel.org
Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com,
	dipankar@in.ibm.com, akpm@linux-foundation.org,
	mathieu.desnoyers@efficios.com, josh@joshtriplett.org,
	tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org,
	dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com,
	oleg@redhat.com
Subject: Re: [PATCH RFC tip/core/rcu 09/16] rcu-tasks: Add an RCU-tasks rude variant
Date: Mon, 16 Mar 2020 15:47:54 -0400
Message-ID: <20200316194754.GA172196@google.com> (raw)
In-Reply-To: <20200312181702.8443-9-paulmck@kernel.org>

On Thu, Mar 12, 2020 at 11:16:55AM -0700, paulmck@kernel.org wrote:
> From: "Paul E. McKenney" <paulmck@kernel.org>
> 
> This commit adds a "rude" variant of RCU-tasks that has as quiescent
> states schedule(), cond_resched_tasks_rcu_qs(), userspace execution,
> and (in theory, anyway) cond_resched().  Updates make use of IPIs and
> force an IPI and a context switch on each online CPU.  This variant
> is useful in some situations in tracing.

Would it be possible to better clarify that the "rude version" works only
from preempt-disabled regions? Is that also true for the "non-rude" version?

Also it would be good to clarify better in cover letter, how these new
flavors relate to the existing Tasks-RCU implementation.

In the existing one, a quiescent state is a task updating its context switch
counters such that it went to sleep at least once, implying there is no
chance it is on an about to be destroyed trampoline.

However, here we are trying to determine if a task state is no longer on an
RQ (which I gleaned from the first patch). Sounds very similar, would the
context switch counters not help in that determination as well? If it is Ok,
it would be good to describe in cover letter about what is exactly is a
quiescent state and what exactly is a reader section in the cover letter, for
both non-rude and rude version. Thanks!

thanks,

 - Joel



> 
> Suggested-by: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> ---
>  include/linux/rcupdate.h |  3 ++
>  kernel/rcu/Kconfig       | 12 +++++-
>  kernel/rcu/tasks.h       | 99 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 113 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
> index 5523145..2be97a8 100644
> --- a/include/linux/rcupdate.h
> +++ b/include/linux/rcupdate.h
> @@ -37,6 +37,7 @@
>  /* Exported common interfaces */
>  void call_rcu(struct rcu_head *head, rcu_callback_t func);
>  void rcu_barrier_tasks(void);
> +void rcu_barrier_tasks_rude(void);
>  void synchronize_rcu(void);
>  
>  #ifdef CONFIG_PREEMPT_RCU
> @@ -138,6 +139,8 @@ static inline void rcu_init_nohz(void) { }
>  #define rcu_note_voluntary_context_switch(t) rcu_tasks_qs(t)
>  void call_rcu_tasks(struct rcu_head *head, rcu_callback_t func);
>  void synchronize_rcu_tasks(void);
> +void call_rcu_tasks_rude(struct rcu_head *head, rcu_callback_t func);
> +void synchronize_rcu_tasks_rude(void);
>  void exit_tasks_rcu_start(void);
>  void exit_tasks_rcu_finish(void);
>  #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
> diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
> index 38475d0..0d43ec1 100644
> --- a/kernel/rcu/Kconfig
> +++ b/kernel/rcu/Kconfig
> @@ -71,7 +71,7 @@ config TREE_SRCU
>  	  This option selects the full-fledged version of SRCU.
>  
>  config TASKS_RCU_GENERIC
> -	def_bool TASKS_RCU
> +	def_bool TASKS_RCU || TASKS_RUDE_RCU
>  	select SRCU
>  	help
>  	  This option enables generic infrastructure code supporting
> @@ -84,6 +84,16 @@ config TASKS_RCU
>  	  only voluntary context switch (not preemption!), idle, and
>  	  user-mode execution as quiescent states.  Not for manual selection.
>  
> +config TASKS_RUDE_RCU
> +	def_bool 0
> +	default n
> +	help
> +	  This option enables a task-based RCU implementation that uses
> +	  only context switch (including preemption) and user-mode
> +	  execution as quiescent states.  It forces IPIs and context
> +	  switches on all online CPUs, including idle ones, so use
> +	  with caution.  Not for manual selection.
> +
>  config RCU_STALL_COMMON
>  	def_bool TREE_RCU
>  	help
> diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
> index d77921e..1d25c50 100644
> --- a/kernel/rcu/tasks.h
> +++ b/kernel/rcu/tasks.h
> @@ -180,6 +180,9 @@ static void __init rcu_tasks_bootup_oddness(void)
>  	else
>  		pr_info("\tTasks RCU enabled.\n");
>  #endif /* #ifdef CONFIG_TASKS_RCU */
> +#ifdef CONFIG_TASKS_RUDE_RCU
> +	pr_info("\tRude variant of Tasks RCU enabled.\n");
> +#endif /* #ifdef CONFIG_TASKS_RUDE_RCU */
>  }
>  
>  #endif /* #ifndef CONFIG_TINY_RCU */
> @@ -410,3 +413,99 @@ static int __init rcu_spawn_tasks_kthread(void)
>  core_initcall(rcu_spawn_tasks_kthread);
>  
>  #endif /* #ifdef CONFIG_TASKS_RCU */
> +
> +#ifdef CONFIG_TASKS_RUDE_RCU
> +
> +////////////////////////////////////////////////////////////////////////
> +//
> +// "Rude" variant of Tasks RCU, inspired by Steve Rostedt's trick of
> +// passing an empty function to schedule_on_each_cpu().  This approach
> +// provides an asynchronous call_rcu_rude() API and batching of concurrent
> +// calls to the synchronous synchronize_rcu_rude() API.  This sends IPIs
> +// far and wide and induces otherwise unnecessary context switches on all
> +// online CPUs, whether online or not.
> +
> +// Empty function to allow workqueues to force a context switch.
> +static void rcu_tasks_be_rude(struct work_struct *work)
> +{
> +}
> +
> +// Wait for one rude RCU-tasks grace period.
> +static void rcu_tasks_rude_wait_gp(struct rcu_tasks *rtp)
> +{
> +	schedule_on_each_cpu(rcu_tasks_be_rude);
> +}
> +EXPORT_SYMBOL_GPL(rcu_tasks_rude_wait_gp);
> +
> +void call_rcu_tasks_rude(struct rcu_head *rhp, rcu_callback_t func);
> +DEFINE_RCU_TASKS(rcu_tasks_rude, rcu_tasks_rude_wait_gp, call_rcu_tasks_rude);
> +
> +/**
> + * call_rcu_tasks_rude() - Queue a callback rude task-based grace period
> + * @rhp: structure to be used for queueing the RCU updates.
> + * @func: actual callback function to be invoked after the grace period
> + *
> + * The callback function will be invoked some time after a full grace
> + * period elapses, in other words after all currently executing RCU
> + * read-side critical sections have completed. call_rcu_tasks_rude()
> + * assumes that the read-side critical sections end at context switch,
> + * cond_resched_rcu_qs(), or transition to usermode execution.  As such,
> + * there are no read-side primitives analogous to rcu_read_lock() and
> + * rcu_read_unlock() because this primitive is intended to determine
> + * that all tasks have passed through a safe state, not so much for
> + * data-strcuture synchronization.
> + *
> + * See the description of call_rcu() for more detailed information on
> + * memory ordering guarantees.
> + */
> +void call_rcu_tasks_rude(struct rcu_head *rhp, rcu_callback_t func)
> +{
> +	call_rcu_tasks_generic(rhp, func, &rcu_tasks_rude);
> +}
> +EXPORT_SYMBOL_GPL(call_rcu_tasks_rude);
> +
> +/**
> + * synchronize_rcu_tasks_rude - wait for a rude rcu-tasks grace period
> + *
> + * Control will return to the caller some time after a rude rcu-tasks
> + * grace period has elapsed, in other words after all currently
> + * executing rcu-tasks read-side critical sections have elapsed.  These
> + * read-side critical sections are delimited by calls to schedule(),
> + * cond_resched_tasks_rcu_qs(), userspace execution, and (in theory,
> + * anyway) cond_resched().
> + *
> + * This is a very specialized primitive, intended only for a few uses in
> + * tracing and other situations requiring manipulation of function preambles
> + * and profiling hooks.  The synchronize_rcu_tasks_rude() function is not
> + * (yet) intended for heavy use from multiple CPUs.
> + *
> + * See the description of synchronize_rcu() for more detailed information
> + * on memory ordering guarantees.
> + */
> +void synchronize_rcu_tasks_rude(void)
> +{
> +	synchronize_rcu_tasks_generic(&rcu_tasks_rude);
> +}
> +EXPORT_SYMBOL_GPL(synchronize_rcu_tasks_rude);
> +
> +/**
> + * rcu_barrier_tasks_rude - Wait for in-flight call_rcu_tasks_rude() callbacks.
> + *
> + * Although the current implementation is guaranteed to wait, it is not
> + * obligated to, for example, if there are no pending callbacks.
> + */
> +void rcu_barrier_tasks_rude(void)
> +{
> +	/* There is only one callback queue, so this is easy.  ;-) */
> +	synchronize_rcu_tasks_rude();
> +}
> +EXPORT_SYMBOL_GPL(rcu_barrier_tasks_rude);
> +
> +static int __init rcu_spawn_tasks_rude_kthread(void)
> +{
> +	rcu_spawn_tasks_kthread_generic(&rcu_tasks_rude);
> +	return 0;
> +}
> +core_initcall(rcu_spawn_tasks_rude_kthread);
> +
> +#endif /* #ifdef CONFIG_TASKS_RUDE_RCU */
> -- 
> 2.9.5
> 

  reply index

Thread overview: 171+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-12 18:16 [PATCH RFC tip/core/rcu 0/16] Prototype RCU usable from idle, exception, offline Paul E. McKenney
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 01/16] sched/core: Add function to sample state of non-running function paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 02/16] rcu: Add per-task state to RCU CPU stall warnings paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 03/16] rcutorture: Add flag to produce non-busy-wait task stalls paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 04/16] rcu-tasks: Move Tasks RCU to its own file paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 05/16] rcu-tasks: Create struct to hold state information paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 06/16] rcu: Reinstate synchronize_rcu_mult() paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 07/16] rcutorture: Add a test for synchronize_rcu_mult() paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 08/16] rcu-tasks: Refactor RCU-tasks to allow variants to be added paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 09/16] rcu-tasks: Add an RCU-tasks rude variant paulmck
2020-03-16 19:47   ` Joel Fernandes [this message]
2020-03-16 20:17     ` Joel Fernandes
2020-03-16 20:32       ` Paul E. McKenney
2020-03-16 21:32         ` Steven Rostedt
2020-03-16 21:45           ` Joel Fernandes
2020-03-16 22:03             ` Steven Rostedt
2020-03-16 22:11               ` Paul E. McKenney
2020-05-10  9:59               ` Lai Jiangshan
2020-05-10 15:49                 ` Paul E. McKenney
2020-05-11  0:06                   ` Lai Jiangshan
2020-05-11  2:44                     ` Paul E. McKenney
2020-05-11  0:44                 ` Masami Hiramatsu
2020-05-11 16:07                 ` Steven Rostedt
2020-05-11 19:48                 ` Steven Rostedt
2020-03-16 20:29     ` Paul E. McKenney
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 10/16] rcutorture: Add torture tests for RCU Tasks Rude paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 11/16] rcu-tasks: Use unique names for RCU-Tasks kthreads and messages paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 12/16] rcu-tasks: Further refactor RCU-tasks to allow adding more variants paulmck
2020-03-12 18:16 ` [PATCH RFC tip/core/rcu 13/16] rcu-tasks: Code movement to allow more Tasks RCU variants paulmck
2020-03-12 18:17 ` [PATCH RFC tip/core/rcu 14/16] rcu: Add an RCU Tasks Trace to simplify protection of tracing hooks paulmck
2020-03-12 18:17 ` [PATCH RFC tip/core/rcu 15/16] rcutorture: Add torture tests for RCU Tasks Trace paulmck
2020-03-12 18:17 ` [PATCH RFC tip/core/rcu 16/16] rcu-tasks: Add stall warnings " paulmck
2020-03-13 14:41 ` [PATCH RFC tip/core/rcu 0/16] Prototype RCU usable from idle, exception, offline Frederic Weisbecker
2020-03-13 15:42   ` Paul E. McKenney
2020-03-15 17:45     ` Mathieu Desnoyers
2020-03-15 17:59       ` Paul E. McKenney
2020-03-16 18:36         ` Steven Rostedt
2020-03-16 18:52           ` Paul E. McKenney
2020-03-16 14:45     ` Frederic Weisbecker
2020-03-16 15:39       ` Paul E. McKenney
2020-03-19  0:10 ` [PATCH RFC v2 tip/core/rcu 0/22] " Paul E. McKenney
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 01/22] sched/core: Add function to sample state of locked-down task paulmck
2020-03-19 17:22     ` Steven Rostedt
2020-03-19 17:35       ` Paul E. McKenney
2020-03-20  2:49         ` Paul E. McKenney
2020-03-20  3:09           ` Steven Rostedt
2020-03-20 16:27             ` Paul E. McKenney
2020-03-24  0:06           ` Joel Fernandes
2020-03-24  0:15             ` Joel Fernandes
2020-03-24 16:26               ` Paul E. McKenney
2020-03-24 15:48             ` Paul E. McKenney
2020-03-24 16:52               ` Joel Fernandes
2020-03-24 17:20                 ` Paul E. McKenney
2020-03-24 18:19                   ` Joel Fernandes
2020-03-25  0:58                     ` Paul E. McKenney
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 02/22] rcu: Add per-task state to RCU CPU stall warnings paulmck
2020-03-19 17:27     ` Steven Rostedt
2020-03-19 17:41       ` Paul E. McKenney
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 03/22] rcutorture: Add flag to produce non-busy-wait task stalls paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 04/22] rcu-tasks: Move Tasks RCU to its own file paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 05/22] rcu-tasks: Create struct to hold state information paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 06/22] rcu: Reinstate synchronize_rcu_mult() paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 07/22] rcutorture: Add a test for synchronize_rcu_mult() paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 08/22] rcu-tasks: Refactor RCU-tasks to allow variants to be added paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 09/22] rcu-tasks: Add an RCU-tasks rude variant paulmck
2020-03-19 19:04     ` Steven Rostedt
2020-03-19 23:58       ` Paul E. McKenney
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 10/22] rcutorture: Add torture tests for RCU Tasks Rude paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 11/22] rcu-tasks: Use unique names for RCU-Tasks kthreads and messages paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 12/22] rcu-tasks: Further refactor RCU-tasks to allow adding more variants paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 13/22] rcu-tasks: Code movement to allow more Tasks RCU variants paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 14/22] rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks paulmck
2020-03-19  1:37     ` Joel Fernandes
2020-03-19  1:58       ` Joel Fernandes
2020-03-19  3:40         ` Paul E. McKenney
2020-03-19 19:42     ` Steven Rostedt
2020-03-20  0:28       ` Paul E. McKenney
2020-03-20  0:48         ` Steven Rostedt
2020-03-20  2:41           ` Paul E. McKenney
2020-03-28 14:06             ` Joel Fernandes
2020-03-28 15:34               ` Paul E. McKenney
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 15/22] rcutorture: Add torture tests for RCU Tasks Trace paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 16/22] rcu-tasks: Add stall warnings " paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 17/22] rcu-tasks: Move #ifdef into tasks.h paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 18/22] rcu-tasks: Add RCU tasks to rcutorture writer stall output paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 19/22] rcu-tasks: Make rcutorture writer stall output include GP state paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 20/22] rcu-tasks: Make RCU Tasks Trace make use of RCU scheduler hooks paulmck
2020-03-19  0:10   ` [PATCH RFC v2 tip/core/rcu 21/22] rcu-tasks: Add a grace-period start time for throttling and debug paulmck
2020-03-19  0:11   ` [PATCH RFC v2 tip/core/rcu 22/22] rcu-tasks: Provide boot parameter to delay IPIs until late in grace period paulmck
2020-03-19 11:31   ` [PATCH RFC v2 tip/core/rcu 0/22] Prototype RCU usable from idle, exception, offline Mathieu Desnoyers
2020-03-19 13:13     ` Paul E. McKenney
     [not found]   ` <20200319104614.11444-1-hdanton@sina.com>
2020-03-19 12:38     ` [PATCH RFC v2 tip/core/rcu 03/22] rcutorture: Add flag to produce non-busy-wait task stalls Paul E. McKenney
     [not found]     ` <20200319133947.12172-1-hdanton@sina.com>
2020-03-19 15:22       ` Paul E. McKenney
     [not found]       ` <20200320040329.9840-1-hdanton@sina.com>
2020-03-20 16:11         ` Paul E. McKenney
     [not found]   ` <20200320071228.9740-1-hdanton@sina.com>
2020-03-20 19:14     ` [PATCH RFC v2 tip/core/rcu 04/22] rcu-tasks: Move Tasks RCU to its own file Paul E. McKenney
2020-03-27 22:23   ` [PATCH RFC v3 tip/core/rcu 0/34] Prototype RCU usable from idle, exception, offline Paul E. McKenney
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 01/34] sched/core: Add function to sample state of locked-down task paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 02/34] rcu: Add per-task state to RCU CPU stall warnings paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 03/34] rcutorture: Add flag to produce non-busy-wait task stalls paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 04/34] rcu-tasks: Move Tasks RCU to its own file paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 05/34] rcu-tasks: Create struct to hold state information paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 06/34] rcu: Reinstate synchronize_rcu_mult() paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 07/34] rcutorture: Add a test for synchronize_rcu_mult() paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 08/34] rcu-tasks: Refactor RCU-tasks to allow variants to be added paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 09/34] rcu-tasks: Add an RCU-tasks rude variant paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 10/34] rcutorture: Add torture tests for RCU Tasks Rude paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 11/34] rcu-tasks: Use unique names for RCU-Tasks kthreads and messages paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 12/34] rcu-tasks: Further refactor RCU-tasks to allow adding more variants paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 13/34] rcu-tasks: Code movement to allow more Tasks RCU variants paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 14/34] rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 15/34] rcutorture: Add torture tests for RCU Tasks Trace paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 16/34] rcu-tasks: Add stall warnings " paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 17/34] rcu-tasks: Move #ifdef into tasks.h paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 18/34] rcu-tasks: Add RCU tasks to rcutorture writer stall output paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 19/34] rcu-tasks: Make rcutorture writer stall output include GP state paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 20/34] rcu-tasks: Make RCU Tasks Trace make use of RCU scheduler hooks paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 21/34] rcu-tasks: Add a grace-period start time for throttling and debug paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 22/34] rcu-tasks: Provide boot parameter to delay IPIs until late in grace period paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 23/34] rcu-tasks: Split ->trc_reader_need_end paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 24/34] rcu-tasks: Add grace-period and IPI counts to statistics paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 25/34] rcu-tasks: Add Kconfig option to mediate smp_mb() vs. IPI paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 26/34] rcu-tasks: Avoid IPIing userspace/idle tasks if kernel is so built paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 27/34] rcu-tasks: Allow rcu_read_unlock_trace() under scheduler locks paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 28/34] rcu-tasks: Disable CPU hotplug across RCU tasks trace scans paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 29/34] rcu-tasks: Handle the running-offline idle-task special case paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 30/34] rcu-tasks: Make RCU tasks trace also wait for idle tasks paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 31/34] rcu-tasks: Add rcu_dynticks_zero_in_eqs() effectiveness statistics paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 32/34] rcu-tasks: Add count for idle tasks on offline CPUs paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 33/34] rcutorture: Add TRACE02 scenario enabling RCU Tasks Trace IPIs paulmck
2020-03-27 22:24     ` [PATCH v3 tip/core/rcu 34/34] rcu-tasks: Add IPI failure count to statistics paulmck
2020-04-15 18:18     ` [PATCH v4 tip/core/rcu 0/38] Prototype RCU usable from idle, exception, offline Paul E. McKenney
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 01/38] rcu: Add comments marking transitions between RCU watching and not paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 02/38] rcu-tasks: Use context-switch hook for PREEMPT=y kernels paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 03/38] sched/core: Add function to sample state of locked-down task paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 04/38] rcu: Add per-task state to RCU CPU stall warnings paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 05/38] rcu-tasks: Move Tasks RCU to its own file paulmck
2020-05-10  7:42         ` Lai Jiangshan
2020-05-10 15:39           ` Paul E. McKenney
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 06/38] rcu-tasks: Create struct to hold state information paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 07/38] rcu: Reinstate synchronize_rcu_mult() paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 08/38] rcutorture: Add a test for synchronize_rcu_mult() paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 09/38] rcu-tasks: Refactor RCU-tasks to allow variants to be added paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 10/38] rcu-tasks: Add an RCU-tasks rude variant paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 11/38] rcutorture: Add torture tests for RCU Tasks Rude paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 12/38] rcu-tasks: Use unique names for RCU-Tasks kthreads and messages paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 13/38] rcu-tasks: Further refactor RCU-tasks to allow adding more variants paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 14/38] rcu-tasks: Code movement to allow more Tasks RCU variants paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 15/38] rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 16/38] rcutorture: Add torture tests for RCU Tasks Trace paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 17/38] rcu-tasks: Add stall warnings " paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 18/38] rcu-tasks: Move #ifdef into tasks.h paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 19/38] rcu-tasks: Add RCU tasks to rcutorture writer stall output paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 20/38] rcu-tasks: Make rcutorture writer stall output include GP state paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 21/38] rcu-tasks: Make RCU Tasks Trace make use of RCU scheduler hooks paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 22/38] rcu-tasks: Add a grace-period start time for throttling and debug paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 23/38] rcu-tasks: Provide boot parameter to delay IPIs until late in grace period paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 24/38] rcu-tasks: Split ->trc_reader_need_end paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 25/38] rcu-tasks: Add grace-period and IPI counts to statistics paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 26/38] rcu-tasks: Add Kconfig option to mediate smp_mb() vs. IPI paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 27/38] rcu-tasks: Avoid IPIing userspace/idle tasks if kernel is so built paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 28/38] rcu-tasks: Allow rcu_read_unlock_trace() under scheduler locks paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 29/38] rcu-tasks: Disable CPU hotplug across RCU tasks trace scans paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 30/38] rcu-tasks: Handle the running-offline idle-task special case paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 31/38] rcu-tasks: Make RCU tasks trace also wait for idle tasks paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 32/38] rcu-tasks: Add rcu_dynticks_zero_in_eqs() effectiveness statistics paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 33/38] rcu-tasks: Add count for idle tasks on offline CPUs paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 34/38] rcutorture: Add TRACE02 scenario enabling RCU Tasks Trace IPIs paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 35/38] rcu-tasks: Add IPI failure count to statistics paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 36/38] rcu-tasks: Allow standalone use of TASKS_{TRACE_,}RCU paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 37/38] ftrace: Use synchronize_rcu_tasks_rude() instead of ftrace_sync() paulmck
2020-04-15 18:19       ` [PATCH v4 tip/core/rcu 38/38] rcu: Don't acquire lock in NMI handler in rcu_nmi_enter_common() paulmck

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