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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt77
1 files changed, 46 insertions, 31 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a10b545c2070..46c60ccb650d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -802,13 +802,14 @@
insecure, please do not use on production kernels.
debug_locks_verbose=
- [KNL] verbose self-tests
- Format=<0|1>
+ [KNL] verbose locking self-tests
+ Format: <int>
Print debugging info while doing the locking API
self-tests.
- We default to 0 (no extra messages), setting it to
- 1 will print _a lot_ more information - normally
- only useful to kernel developers.
+ Bitmask for the various LOCKTYPE_ tests. Defaults to 0
+ (no extra messages), setting it to -1 (all bits set)
+ will print _a_lot_ more information - normally only
+ useful to lockdep developers.
debug_objects [KNL] Enable object debugging
@@ -944,12 +945,6 @@
causing system reset or hang due to sending
INIT from AP to BSP.
- perf_v4_pmi= [X86,INTEL]
- Format: <bool>
- Disable Intel PMU counter freezing feature.
- The feature only exists starting from
- Arch Perfmon v4 (Skylake and newer).
-
disable_ddw [PPC/PSERIES]
Disable Dynamic DMA Window support. Use this
to workaround buggy firmware.
@@ -3458,20 +3453,6 @@
For example, to override I2C bus2:
omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
- oprofile.timer= [HW]
- Use timer interrupt instead of performance counters
-
- oprofile.cpu_type= Force an oprofile cpu type
- This might be useful if you have an older oprofile
- userland or if you want common events.
- Format: { arch_perfmon }
- arch_perfmon: [X86] Force use of architectural
- perfmon on Intel CPUs instead of the
- CPU specific event set.
- timer: [X86] Force use of architectural NMI
- timer mode (see also oprofile.timer
- for generic hr timer mode)
-
oops=panic Always panic on oopses. Default is to just kill the
process, but there is a small probability of
deadlocking the machine.
@@ -3916,6 +3897,13 @@
Format: {"off"}
Disable Hardware Transactional Memory
+ preempt= [KNL]
+ Select preemption mode if you have CONFIG_PREEMPT_DYNAMIC
+ none - Limited to cond_resched() calls
+ voluntary - Limited to cond_resched() and might_sleep() calls
+ full - Any section that isn't explicitly preempt disabled
+ can be preempted anytime.
+
print-fatal-signals=
[KNL] debug: print fatal signals
@@ -4092,6 +4080,10 @@
value, meaning that RCU_SOFTIRQ is used by default.
Specify rcutree.use_softirq=0 to use rcuc kthreads.
+ But note that CONFIG_PREEMPT_RT=y kernels disable
+ this kernel boot parameter, forcibly setting it
+ to zero.
+
rcutree.rcu_fanout_exact= [KNL]
Disable autobalancing of the rcu_node combining
tree. This is used by rcutorture, and might
@@ -4179,12 +4171,6 @@
Set wakeup interval for idle CPUs that have
RCU callbacks (RCU_FAST_NO_HZ=y).
- rcutree.rcu_idle_lazy_gp_delay= [KNL]
- Set wakeup interval for idle CPUs that have
- only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y).
- Lazy RCU callbacks are those which RCU can
- prove do nothing more than free memory.
-
rcutree.rcu_kick_kthreads= [KNL]
Cause the grace-period kthread to get an extra
wake_up() if it sleeps three times longer than
@@ -4338,6 +4324,14 @@
stress RCU, they don't participate in the actual
test, hence the "fake".
+ rcutorture.nocbs_nthreads= [KNL]
+ Set number of RCU callback-offload togglers.
+ Zero (the default) disables toggling.
+
+ rcutorture.nocbs_toggle= [KNL]
+ Set the delay in milliseconds between successive
+ callback-offload toggling attempts.
+
rcutorture.nreaders= [KNL]
Set number of RCU readers. The value -1 selects
N-1, where N is the number of CPUs. A value
@@ -4470,6 +4464,13 @@
only normal grace-period primitives. No effect
on CONFIG_TINY_RCU kernels.
+ But note that CONFIG_PREEMPT_RT=y kernels enables
+ this kernel boot parameter, forcibly setting
+ it to the value one, that is, converting any
+ post-boot attempt at an expedited RCU grace
+ period to instead use normal non-expedited
+ grace-period processing.
+
rcupdate.rcu_task_ipi_delay= [KNL]
Set time in jiffies during which RCU tasks will
avoid sending IPIs, starting with the beginning
@@ -4557,6 +4558,12 @@
refscale.verbose= [KNL]
Enable additional printk() statements.
+ refscale.verbose_batched= [KNL]
+ Batch the additional printk() statements. If zero
+ (the default) or negative, print everything. Otherwise,
+ print every Nth verbose statement, where N is the value
+ specified.
+
relax_domain_level=
[KNL, SMP] Set scheduler's default relax_domain_level.
See Documentation/admin-guide/cgroup-v1/cpusets.rst.
@@ -5331,6 +5338,14 @@
are running concurrently, especially on systems
with rotating-rust storage.
+ torture.verbose_sleep_frequency= [KNL]
+ Specifies how many verbose printk()s should be
+ emitted between each sleep. The default of zero
+ disables verbose-printk() sleeping.
+
+ torture.verbose_sleep_duration= [KNL]
+ Duration of each verbose-printk() sleep in jiffies.
+
tp720= [HW,PS2]
tpm_suspend_pcr=[HW,TPM]