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
next prev parent reply other threads:[~2026-09-19 0:01 UTC|newest]
Thread overview: 53+ 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 15:55 ` Boqun Feng
2026-09-25 19:08 ` Mathieu Desnoyers
2026-09-20 14:46 ` Gary Guo
2026-09-20 15:44 ` Mathieu Desnoyers
2026-09-20 15:57 ` Gary Guo
2026-09-25 19:19 ` Mathieu Desnoyers
2026-09-25 20:17 ` Gary Guo
2026-09-25 20:18 ` 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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