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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 13:19:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 13:19:28 -0700
commit68cadad11fe2ddd126b37a8fba3726be7fa0f5c6 (patch)
tree319a5a701f4e51120a138b23f78cacf116f3cc43 /Documentation/admin-guide
parent727dbda16b83600379061c4ca8270ef3e2f51922 (diff)
parentfe24a0b63278808013e1756e235e0e17e8bae281 (diff)
Merge tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes, perhaps most notably simplifying SRCU_NOTIFIER_INIT() as suggested - RCU Tasks updates, most notably treating Tasks RCU callbacks as lazy while still treating synchronous grace periods as urgent. Also fixes one bug that restores the ability to apply debug-objects to RCU Tasks and another that fixes a race condition that could result in false-positive failures of the boot-time self-test code - RCU-scalability performance-test updates, most notably adding the ability to measure the RCU-Tasks's grace-period kthread's CPU consumption. This proved quite useful for the RCU Tasks work - Reference-acquisition/release performance-test updates, including a fix for an uninitialized wait_queue_head_t - Miscellaneous torture-test updates - Torture-test scripting updates, including removal of the non-longer-functional formal-verification scripts, test builds of individual RCU Tasks flavors, better diagnostics for loss of connectivity for distributed rcutorture tests, disabling of reboot loops in qemu/KVM-based rcutorture testing, and passing of init parameters to rcutorture's init program * tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (64 commits) rcu: Use WRITE_ONCE() for assignments to ->next for rculist_nulls rcu: Make the rcu_nocb_poll boot parameter usable via boot config rcu: Mark __rcu_irq_enter_check_tick() ->rcu_urgent_qs load srcu,notifier: Remove #ifdefs in favor of SRCU Tiny srcu_usage rcutorture: Stop right-shifting torture_random() return values torture: Stop right-shifting torture_random() return values torture: Move stutter_wait() timeouts to hrtimers torture: Move torture_shuffle() timeouts to hrtimers torture: Move torture_onoff() timeouts to hrtimers torture: Make torture_hrtimeout_*() use TASK_IDLE torture: Add lock_torture writer_fifo module parameter torture: Add a kthread-creation callback to _torture_create_kthread() rcu-tasks: Fix boot-time RCU tasks debug-only deadlock rcu-tasks: Permit use of debug-objects with RCU Tasks flavors checkpatch: Complain about unexpected uses of RCU Tasks Trace torture: Cause mkinitrd.sh to indicate failure on compile errors torture: Make init program dump command-line arguments torture: Switch qemu from -nographic to -display none torture: Add init-program support for loongarch torture: Avoid torture-test reboot loops ...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt56
1 files changed, 55 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 6ff63638ed82..77bda843df34 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2938,6 +2938,10 @@
locktorture.torture_type= [KNL]
Specify the locking implementation to test.
+ locktorture.writer_fifo= [KNL]
+ Run the write-side locktorture kthreads at
+ sched_set_fifo() real-time priority.
+
locktorture.verbose= [KNL]
Enable additional printk() statements.
@@ -4949,6 +4953,15 @@
test until boot completes in order to avoid
interference.
+ rcuscale.kfree_by_call_rcu= [KNL]
+ In kernels built with CONFIG_RCU_LAZY=y, test
+ call_rcu() instead of kfree_rcu().
+
+ rcuscale.kfree_mult= [KNL]
+ Instead of allocating an object of size kfree_obj,
+ allocate one of kfree_mult * sizeof(kfree_obj).
+ Defaults to 1.
+
rcuscale.kfree_rcu_test= [KNL]
Set to measure performance of kfree_rcu() flooding.
@@ -4974,6 +4987,12 @@
Number of loops doing rcuscale.kfree_alloc_num number
of allocations and frees.
+ rcuscale.minruntime= [KNL]
+ Set the minimum test run time in seconds. This
+ does not affect the data-collection interval,
+ but instead allows better measurement of things
+ like CPU consumption.
+
rcuscale.nreaders= [KNL]
Set number of RCU readers. The value -1 selects
N, where N is the number of CPUs. A value
@@ -4988,7 +5007,7 @@
the same as for rcuscale.nreaders.
N, where N is the number of CPUs
- rcuscale.perf_type= [KNL]
+ rcuscale.scale_type= [KNL]
Specify the RCU implementation to test.
rcuscale.shutdown= [KNL]
@@ -5004,6 +5023,11 @@
in microseconds. The default of zero says
no holdoff.
+ rcuscale.writer_holdoff_jiffies= [KNL]
+ Additional write-side holdoff between grace
+ periods, but in jiffies. The default of zero
+ says no holdoff.
+
rcutorture.fqs_duration= [KNL]
Set duration of force_quiescent_state bursts
in microseconds.
@@ -5285,6 +5309,13 @@
number avoids disturbing real-time workloads,
but lengthens grace periods.
+ rcupdate.rcu_task_lazy_lim= [KNL]
+ Number of callbacks on a given CPU that will
+ cancel laziness on that CPU. Use -1 to disable
+ cancellation of laziness, but be advised that
+ doing so increases the danger of OOM due to
+ callback flooding.
+
rcupdate.rcu_task_stall_info= [KNL]
Set initial timeout in jiffies for RCU task stall
informational messages, which give some indication
@@ -5314,6 +5345,29 @@
A change in value does not take effect until
the beginning of the next grace period.
+ rcupdate.rcu_tasks_lazy_ms= [KNL]
+ Set timeout in milliseconds RCU Tasks asynchronous
+ callback batching for call_rcu_tasks().
+ A negative value will take the default. A value
+ of zero will disable batching. Batching is
+ always disabled for synchronize_rcu_tasks().
+
+ rcupdate.rcu_tasks_rude_lazy_ms= [KNL]
+ Set timeout in milliseconds RCU Tasks
+ Rude asynchronous callback batching for
+ call_rcu_tasks_rude(). A negative value
+ will take the default. A value of zero will
+ disable batching. Batching is always disabled
+ for synchronize_rcu_tasks_rude().
+
+ rcupdate.rcu_tasks_trace_lazy_ms= [KNL]
+ Set timeout in milliseconds RCU Tasks
+ Trace asynchronous callback batching for
+ call_rcu_tasks_trace(). A negative value
+ will take the default. A value of zero will
+ disable batching. Batching is always disabled
+ for synchronize_rcu_tasks_trace().
+
rcupdate.rcu_self_test= [KNL]
Run the RCU early boot self tests