From: Steven Rostedt <rostedt@goodmis.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, dhowells@redhat.com,
edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com,
joel@joelfernandes.org,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Andrii Nakryiko <andriin@fb.com>
Subject: Re: [PATCH RFC v2 tip/core/rcu 14/22] rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks
Date: Thu, 19 Mar 2020 15:42:39 -0400 [thread overview]
Message-ID: <20200319154239.6d67877d@gandalf.local.home> (raw)
In-Reply-To: <20200319001100.24917-14-paulmck@kernel.org>
On Wed, 18 Mar 2020 17:10:52 -0700
paulmck@kernel.org wrote:
> From: "Paul E. McKenney" <paulmck@kernel.org>
>
> Because RCU does not watch exception early-entry/late-exit, idle-loop,
> or CPU-hotplug execution, protection of tracing and BPF operations is
> needlessly complicated. This commit therefore adds a variant of
> Tasks RCU that:
>
> o Has explicit read-side markers to allow finite grace periods in
> the face of in-kernel loops for PREEMPT=n builds. These markers
> are rcu_read_lock_trace() and rcu_read_unlock_trace().
>
> o Protects code in the idle loop, exception entry/exit, and
> CPU-hotplug code paths. In this respect, RCU-tasks trace is
> similar to SRCU, but with lighter-weight readers.
>
> o Avoids expensive read-side instruction, having overhead similar
> to that of Preemptible RCU.
>
> There are of course downsides:
>
> o The grace-period code can send IPIs to CPUs, even when those CPUs
> are in the idle loop or in nohz_full userspace. This will be
> addressed by later commits.
>
> o It is necessary to scan the full tasklist, much as for Tasks RCU.
>
> o There is a single callback queue guarded by a single lock,
> again, much as for Tasks RCU. However, those early use cases
> that request multiple grace periods in quick succession are
> expected to do so from a single task, which makes the single
> lock almost irrelevant. If needed, multiple callback queues
> can be provided using any number of schemes.
>
> Perhaps most important, this variant of RCU does not affect the vanilla
> flavors, rcu_preempt and rcu_sched. The fact that RCU Tasks Trace
> readers can operate from idle, offline, and exception entry/exit in no
> way enables rcu_preempt and rcu_sched readers to do so.
>
> This effort benefited greatly from off-list discussions of BPF
> requirements with Alexei Starovoitov and Andrii Nakryiko. At least
> some of the on-list discussions are captured in the Link: tags below.
> In addition, KCSAN was quite helpful in finding some early bugs.
If we have this, do we still need to have RCU Tasks Rude flavor?
>
> Link: https://lore.kernel.org/lkml/20200219150744.428764577@infradead.org/
> Link: https://lore.kernel.org/lkml/87mu8p797b.fsf@nanos.tec.linutronix.de/
> Link: https://lore.kernel.org/lkml/20200225221305.605144982@linutronix.de/
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
> Cc: Andrii Nakryiko <andriin@fb.com>
> ---
> include/linux/rcupdate_trace.h | 84 ++++++++++
> include/linux/sched.h | 8 +
> init/init_task.c | 4 +
> kernel/fork.c | 4 +
> kernel/rcu/Kconfig | 12 +-
> kernel/rcu/tasks.h | 359 ++++++++++++++++++++++++++++++++++++++++-
> 6 files changed, 462 insertions(+), 9 deletions(-)
> create mode 100644 include/linux/rcupdate_trace.h
>
> diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
> index 0d43ec1..187226b 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 || TASKS_RUDE_RCU
> + def_bool TASKS_RCU || TASKS_RUDE_RCU || TASKS_TRACE_RCU
> select SRCU
> help
> This option enables generic infrastructure code supporting
> @@ -94,6 +94,16 @@ config TASKS_RUDE_RCU
> switches on all online CPUs, including idle ones, so use
> with caution. Not for manual selection.
>
> +config TASKS_TRACE_RCU
> + def_bool 0
> + default n
Again, no need for "default n"
> + help
> + This option enables a task-based RCU implementation that uses
> + explicit rcu_read_lock_trace() read-side markers, and allows
> + these readers to appear in the idle loop as well as on the CPU
> + hotplug code paths. It can force IPIs on online CPUs, including
> + idle ones, so use with caution. Not for manual selection.
And no real need for "Not for manual selection".
> +
> config RCU_STALL_COMMON
> def_bool TREE_RCU
> help
> @@ -480,10 +489,10 @@ core_initcall(rcu_spawn_tasks_kthread);
> //
> // "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.
> +// provides an asynchronous call_rcu_tasks_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.
This looks out of place for this patch. Perhaps you fixed this code and
applied it to the wrong patch?
>
> // Empty function to allow workqueues to force a context switch.
> static void rcu_tasks_be_rude(struct work_struct *work)
> @@ -569,3 +578,337 @@ static int __init rcu_spawn_tasks_rude_kthread(void)
> core_initcall(rcu_spawn_tasks_rude_kthread);
>
> #endif /* #ifdef CONFIG_TASKS_RUDE_RCU */
> +
> +////////////////////////////////////////////////////////////////////////
> +//
> +// Tracing variant of Tasks RCU. This variant is designed to be used
> +// to protect tracing hooks, including those of BPF. This variant
> +// therefore:
> +//
> +// 1. Has explicit read-side markers to allow finite grace periods
> +// in the face of in-kernel loops for PREEMPT=n builds.
> +//
> +// 2. Protects code in the idle loop, exception entry/exit, and
> +// CPU-hotplug code paths, similar to the capabilities of SRCU.
> +//
> +// 3. Avoids expensive read-side instruction, having overhead similar
> +// to that of Preemptible RCU.
> +//
> +// There are of course downsides. The grace-period code can send IPIs to
> +// CPUs, even when those CPUs are in the idle loop or in nohz_full userspace.
> +// It is necessary to scan the full tasklist, much as for Tasks RCU. There
> +// is a single callback queue guarded by a single lock, again, much as for
> +// Tasks RCU. If needed, these downsides can be at least partially remedied.
> +//
> +// Perhaps most important, this variant of RCU does not affect the vanilla
> +// flavors, rcu_preempt and rcu_sched. The fact that RCU Tasks Trace
> +// readers can operate from idle, offline, and exception entry/exit in no
> +// way allows rcu_preempt and rcu_sched readers to also do so.
> +
> +// The lockdep state must be outside of #ifdef to be useful.
> +#ifdef CONFIG_DEBUG_LOCK_ALLOC
> +static struct lock_class_key rcu_lock_trace_key;
> +struct lockdep_map rcu_trace_lock_map =
> + STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_trace", &rcu_lock_trace_key);
> +EXPORT_SYMBOL_GPL(rcu_trace_lock_map);
> +#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
> +
> +#ifdef CONFIG_TASKS_TRACE_RCU
> +
> +atomic_t trc_n_readers_need_end; // Number of waited-for readers.
> +DECLARE_WAIT_QUEUE_HEAD(trc_wait); // List of holdout tasks.
> +
> +// Record outstanding IPIs to each CPU. No point in sending two...
> +static DEFINE_PER_CPU(bool, trc_ipi_to_cpu);
> +
> +/* If we are the last reader, wake up the grace-period kthread. */
> +void rcu_read_unlock_trace_special(struct task_struct *t)
> +{
> + WRITE_ONCE(t->trc_reader_need_end, false);
> + if (atomic_dec_and_test(&trc_n_readers_need_end))
> + wake_up(&trc_wait);
Hmm, this can't be called in places that hold the rq->lock can it?
-- Steve
> +}
> +EXPORT_SYMBOL_GPL(rcu_read_unlock_trace_special);
> +
> +/* Add a task to the holdout list, if it is not already on the list. */
> +static void trc_add_holdout(struct task_struct *t, struct list_head *bhp)
> +{
> + if (list_empty(&t->trc_holdout_list)) {
> + get_task_struct(t);
> + list_add(&t->trc_holdout_list, bhp);
> + }
> +}
> +ndif /* #else #ifdef CONFIG_TASKS_TRACE_RCU */
next prev parent reply other threads:[~2020-03-19 19:42 UTC|newest]
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
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 [this message]
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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