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From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: kernel-team@meta.com,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Boqun Feng <boqun@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	lkmm@lists.linux.dev, Zqiang <qiang.zhang@linux.dev>,
	Wang Lian <lianux.mm@gmail.com>,
	Kunwu Chan <kunwu.chan@gmail.com>,
	Bradley Morgan <brads@mainlining.org>,
	"Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH 18/28] doc: Add hazptrtorture module parameters
Date: Fri, 18 Sep 2026 17:00:46 -0700	[thread overview]
Message-ID: <20260919000056.3132131-18-paulmck@kernel.org> (raw)
In-Reply-To: <e9669b34-12c2-4cf2-a887-315f581f0789@paulmck-laptop>

Add the hazard-pointer-torture module parameters to kernel-parameters.txt.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: <rcu@vger.kernel.org>
Cc: <lkmm@lists.linux.dev>
---
 .../admin-guide/kernel-parameters.txt         | 96 +++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 68647ff4bdd2..e93768fd5c55 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1964,6 +1964,102 @@ Kernel parameters
 			for 64-bit NUMA, off otherwise.
 			Format: 0 | 1 (for off | on)
 
+	hazptrtorture.defer_modulus= [KNL]
+			Defer release of the hazard pointer on average
+			one out of the specified number of times.  Zero
+			disables.  Negative one defaults to 1,000 times
+			nr_cpu_ids, unless hazptr.kthread_do_pending_ms is
+			equal to zero, in which case it instead defaults
+			to zero (disabled).
+
+	hazptrtorture.irq_acquire= [KNL]
+			Acquire hazard pointers from an irq handler on average
+			one out of the specified number of times.  Zero
+			disables.  Negative one defaults to 1,000 times
+			nr_cpu_ids.
+
+	hazptrtorture.irq_release= [KNL]
+			Release hazard pointers from an irq handler on average
+			one out of the specified number of times.  Zero
+			disables.  Negative one defaults to 1,000 times
+			nr_cpu_ids.
+
+	hazptrtorture.kthread_do_pending_ms= [KNL]
+			Interval between cleanup of pending (deferred)
+			hazard-pointer releases in milliseconds.
+			Zero disables.	Negative one defaults to three
+			milliseconds, unless hazptr.kthread_do_pending_ms
+			is equal to zero, in which case it instead
+			defaults to zero (disabled).
+
+	hazptrtorture.nreaders= [KNL]
+			Number of hazard-pointer reader kthreads, each
+			of which repeatedly acquires and releases hazard
+			pointers.  If the value is zero, one reader
+			is spawned.  If the value is less than zero,
+			the absolute value is multiplied by the number
+			of online CPUs at initialization time.
+
+	hazptrtorture.nwriters= [KNL]
+			Controls whether or not there is a writer.
+			There is at most one writer, so this value must
+			be zero or one.
+
+	hazptrtorture.onoff_holdoff= [KNL]
+			Set time (s) after boot for CPU-hotplug testing.
+
+	hazptrtorture.onoff_interval= [KNL]
+			Set time (jiffies) between CPU-hotplug operations,
+			or zero to disable CPU-hotplug testing.
+
+	hazptrtorture.preempt_duration= [KNL]
+			Set duration (in milliseconds) of preemptions
+			by a high-priority FIFO real-time task.  Set to
+			zero (the default) to disable.	The CPUs to
+			preempt are selected randomly from the set that
+			are online at a given point in time.  Races with
+			CPUs going offline are ignored, with that attempt
+			at preemption skipped.
+
+	hazptrtorture.preempt_interval= [KNL]
+			Set interval (in milliseconds, defaulting to one
+			second) between preemptions by a high-priority
+			FIFO real-time task.  This delay is mediated
+			by an hrtimer and is further fuzzed to avoid
+			inadvertent synchronizations.
+
+	hazptrtorture.reader_sleep_us= [KNL]
+			Set occassional read-side sleep time in
+			microseconds, defaulting to zero for disabled.
+
+	hazptrtorture.shuffle_interval= [KNL]
+			Set task-shuffle interval (seconds).  Shuffling
+			tasks allows some CPUs to go into dyntick-idle
+			mode during the hazptrtorture test.
+
+	hazptrtorture.shutdown_secs= [KNL]
+			Set time (s) after boot system shutdown.  This
+			is useful for hands-off automated testing.
+
+	hazptrtorture.stat_interval= [KNL]
+			Time (s) between statistics printk()s.
+
+	hazptrtorture.stutter= [KNL]
+			Time (s) to stutter testing, for example,
+			specifying three seconds (the default) causes
+			the test to run for three seconds, wait
+			for five seconds, and so on.  This tests the
+			hazard-pointers primitives' ability to transition
+			abruptly to and from idle.  Setting this to zero
+			disables stuttering.
+
+	hazptrtorture.torture_type= [KNL]
+			Specify the hazard-pointers implementation
+			to test.
+
+	hazptrtorture.verbose= [KNL]
+			Enable additional printk() statements.
+
 	hd=		[EIDE] (E)IDE hard drive subsystem geometry
 			Format: <cyl>,<head>,<sect>
 
-- 
2.40.1


  parent reply	other threads:[~2026-09-19  0:01 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-18 23:59 [PATCH RFC v3 0/28] Simple hazard-pointer implementation and torture tests Paul E. McKenney
2026-09-19  0:00 ` [PATCH 01/28] hazptr: Implement Hazard Pointers Paul E. McKenney
2026-09-19 11:12   ` Bradley Morgan
2026-09-19 16:30   ` Linus Torvalds
2026-09-19 16:34     ` Bradley Morgan
2026-09-19 17:00       ` Linus Torvalds
2026-09-19 17:09         ` Mathieu Desnoyers
2026-09-19 18:09           ` Boqun Feng
2026-09-19 17:19         ` Mathieu Desnoyers
2026-09-19 18:18         ` Paul E. McKenney
2026-09-19 23:58         ` Bradley Morgan
2026-09-19 16:41   ` Bradley Morgan
2026-09-19 17:56     ` Paul E. McKenney
2026-09-19  0:00 ` [PATCH 02/28] hazptr: Add refscale test Paul E. McKenney
2026-09-19  0:00 ` [PATCH 03/28] torture: Add a hazptrtorture.c torture test Paul E. McKenney
2026-09-19  0:00 ` [PATCH 04/28] hazptrtorture: Add testing of on-stack hazptr_ctx structures Paul E. McKenney
2026-09-19  0:00 ` [PATCH 05/28] hazptrtorture: Add microsecond-scale sleep in readers Paul E. McKenney
2026-09-19  0:00 ` [PATCH 06/28] hazptrtorture: Enable system-independent CPU overcommit Paul E. McKenney
2026-09-19  0:00 ` [PATCH 07/28] torture: Add a stutter_will_wait() function Paul E. McKenney
2026-09-19  0:00 ` [PATCH 08/28] hazptrtorture: Use mnemonic local variables for context information Paul E. McKenney
2026-09-19  0:00 ` [PATCH 09/28] hazptrtorture: Split hazptr_torture_reader_tail() from hazptr_torture_reader() Paul E. McKenney
2026-09-19  0:00 ` [PATCH 10/28] hazptrtorture: Add kthread to release deferred hazard pointers Paul E. McKenney
2026-09-19  0:00 ` [PATCH 11/28] hazptrtorture: Defer release of " Paul E. McKenney
2026-09-19  0:00 ` [PATCH 12/28] hazptrtorture: Add irq_acquire to acquire hazptr from irq Paul E. McKenney
2026-09-19  0:00 ` [PATCH 13/28] hazptrtorture: Use task_state_to_char() for task-state reporting Paul E. McKenney
2026-09-19  0:00 ` [PATCH 14/28] hazptrtorture: Pass hazptr_pending to hazptr_torture_reader_tail() Paul E. McKenney
2026-09-19  0:00 ` [PATCH 15/28] hazptrtorture: Add the ability to disable the writer kthread Paul E. McKenney
2026-09-19  0:00 ` [PATCH 16/28] hazptrtorture: Add irq_release to release hazptr from irq Paul E. McKenney
2026-09-19  0:00 ` [PATCH 17/28] hazptrtorture: Accumulate operation statistics Paul E. McKenney
2026-09-19  0:00 ` Paul E. McKenney [this message]
2026-09-19  0:00 ` [PATCH 19/28] hazptr: Permit detaching hazard pointers from contexts Paul E. McKenney
2026-09-19 11:42   ` Boqun Feng
2026-09-19 11:43     ` Boqun Feng
2026-09-19  0:00 ` [PATCH 20/28] hazptrtorture: Detach deferred and IPIed hazard pointers Paul E. McKenney
2026-09-19  0:00 ` [PATCH 21/28] hazptr: Introduce CONFIG_HAZPTR_DEBUG misuse detection Paul E. McKenney
2026-09-19  0:00 ` [PATCH 22/28] hazptrtorture: Fix hazptr ownership issue Paul E. McKenney
2026-09-19  0:00 ` [PATCH 23/28] hazptrtorture: Enable CONFIG_HAZPTR_DEBUG Paul E. McKenney
2026-09-19  0:00 ` [PATCH 24/28] hazptr: Upgrade kernel-doc headers Paul E. McKenney
2026-09-19  0:00 ` [PATCH 25/28] hazptrtorture: Fix inverted sleep condition in do_pending kthread Paul E. McKenney
2026-09-19  0:00 ` [PATCH 26/28] hazptr: Implement two-phase wildcard scan Paul E. McKenney
2026-09-19 13:28   ` Boqun Feng
2026-09-20 12:46     ` Mathieu Desnoyers
2026-09-20 14:46   ` Gary Guo
2026-09-20 15:44     ` Mathieu Desnoyers
2026-09-19  0:00 ` [PATCH 27/28] hazptr: handle NULL address in hazptr_detach Paul E. McKenney
2026-09-19  0:00 ` [PATCH 28/28] torture.sh: Add hazptr torturing Paul E. McKenney
2026-09-19 11:18   ` Bradley Morgan

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