[PATCH 17/23] doc: Catch-up update for locktorture module parameters

From: Frederic Weisbecker
Date: Tue Oct 10 2023 - 08:01:26 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>

This commit documents recently added locktorture module parameters.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
---
.../admin-guide/kernel-parameters.txt | 50 +++++++++++++++++--
1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 300e2c30986c..47f8b1cef4fd 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2913,6 +2913,11 @@
to extract confidential information from the kernel
are also disabled.

+ locktorture.acq_writer_lim= [KNL]
+ Set the time limit in jiffies for a lock
+ acquisition. Acquisitions exceeding this limit
+ will result in a splat once they do complete.
+
locktorture.call_rcu_chains= [KNL]
Specify the number of self-propagating call_rcu()
chains to set up. These are used to ensure that
@@ -2920,6 +2925,18 @@
in progress at any given time. Defaults to 0,
which disables these call_rcu() chains.

+ locktorture.long_hold= [KNL]
+ Specify the duration in milliseconds for the
+ occasional long-duration lock hold time. Defaults
+ to 100 milliseconds. Select 0 to disable.
+
+ locktorture.nested_locks= [KNL]
+ Specify the maximum lock nesting depth that
+ locktorture is to exercise, up to a limit of 8
+ (MAX_NESTED_LOCKS). Specify zero to disable.
+ Note that this parameter is ineffective on types
+ of locks that do not support nested acquisition.
+
locktorture.nreaders_stress= [KNL]
Set the number of locking read-acquisition kthreads.
Defaults to being automatically set based on the
@@ -2935,6 +2952,29 @@
Set time (s) between CPU-hotplug operations, or
zero to disable CPU-hotplug testing.

+ locktorture.readers_bind= [KNL]
+ Specify the list of CPUs to which the readers are
+ to be bound.
+
+ locktorture.rt_boost= [KNL]
+ Do periodic testing of real-time lock priority
+ boosting. Select 0 to disable, 1 to boost
+ only rt_mutex, and 2 to boost unconditionally.
+ Defaults to 2, which might seem to be an
+ odd choice, but which should be harmless for
+ non-real-time spinlocks, due to their disabling
+ of preemption. Note that non-realtime mutexes
+ disable boosting.
+
+ locktorture.rt_boost_factor= [KNL]
+ Number that determines how often and for how
+ long priority boosting is exercised. This is
+ scaled down by the number of writers, so that the
+ number of boosts per unit time remains roughly
+ constant as the number of writers increases.
+ On the other hand, the duration of each boost
+ increases with the number of writers.
+
locktorture.shuffle_interval= [KNL]
Set task-shuffle interval (jiffies). Shuffling
tasks allows some CPUs to go into dyntick-idle
@@ -2957,13 +2997,17 @@
locktorture.torture_type= [KNL]
Specify the locking implementation to test.

+ locktorture.verbose= [KNL]
+ Enable additional printk() statements.
+
+ locktorture.writers_bind= [KNL]
+ Specify the list of CPUs to which the writers are
+ to be bound.
+
locktorture.writer_fifo= [KNL]
Run the write-side locktorture kthreads at
sched_set_fifo() real-time priority.

- locktorture.verbose= [KNL]
- Enable additional printk() statements.
-
logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
Format: <irq>

--
2.34.1