All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com,
	rostedt@goodmis.org, "Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH RFC v2 18/24] doc: Add hazptrtorture module parameters
Date: Wed, 15 Jul 2026 17:18:03 -0700	[thread overview]
Message-ID: <20260716001809.11084-18-paulmck@kernel.org> (raw)
In-Reply-To: <23e34c2e-67fd-45da-b130-e70a131a59ea@paulmck-laptop>

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

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 .../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 b5493a7f8f2281..7977ce806a2647 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1951,6 +1951,102 @@ 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:[~2026-07-16  0:18 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-16  0:18 [PATCH RFC v2 0/24] Simple hazard-pointer implementation and torture tests Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 01/24] hazptr: Implement Hazard Pointers Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 02/24] hazptr: Add refscale test Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 03/24] torture: Add a hazptrtorture.c torture test Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 04/24] hazptrtorture: Add testing of on-stack hazptr_ctx structures Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 05/24] hazptrtorture: Add microsecond-scale sleep in readers Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 06/24] hazptrtorture: Enable system-independent CPU overcommit Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 07/24] torture: Add a stutter_will_wait() function Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 08/24] hazptrtorture: Use mnemonic local variables for context information Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 09/24] hazptrtorture: Split hazptr_torture_reader_tail() from hazptr_torture_reader() Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 10/24] hazptrtorture: Add kthread to release deferred hazard pointers Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 11/24] hazptrtorture: Defer release of " Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 12/24] hazptrtorture: Add irq_acquire to acquire hazptr from irq Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 13/24] hazptrtorture: Use task_state_to_char() for task-state reporting Paul E. McKenney
2026-07-16  0:17 ` [PATCH RFC v2 14/24] hazptrtorture: Pass hazptr_pending to hazptr_torture_reader_tail() Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 15/24] hazptrtorture: Add the ability to disable the writer kthread Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 16/24] hazptrtorture: Add irq_release to release hazptr from irq Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 17/24] hazptrtorture: Accumulate operation statistics Paul E. McKenney
2026-07-16  0:18 ` Paul E. McKenney [this message]
2026-07-16  0:18 ` [PATCH RFC v2 19/24] hazptr: Permit detaching hazard pointers from contexts Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 20/24] hazptrtorture: Detach deferred and IPIed hazard pointers Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 21/24] hazptr: Introduce CONFIG_HAZPTR_DEBUG misuse detection Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 22/24] hazptrtorture: Fix hazptr ownership issue Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 23/24] hazptrtorture: Enable CONFIG_HAZPTR_DEBUG Paul E. McKenney
2026-07-16  0:18 ` [PATCH RFC v2 24/24] hazptr: Upgrade kernel-doc headers Paul E. McKenney

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260716001809.11084-18-paulmck@kernel.org \
    --to=paulmck@kernel.org \
    --cc=kernel-team@meta.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rcu@vger.kernel.org \
    --cc=rostedt@goodmis.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.