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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt85
1 files changed, 82 insertions, 3 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 3f1cc5e317ed..f8d9af5d51e5 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4893,6 +4893,18 @@
rcupdate.rcu_cpu_stall_timeout= [KNL]
Set timeout for RCU CPU stall warning messages.
+ The value is in seconds and the maximum allowed
+ value is 300 seconds.
+
+ rcupdate.rcu_exp_cpu_stall_timeout= [KNL]
+ Set timeout for expedited RCU CPU stall warning
+ messages. The value is in milliseconds
+ and the maximum allowed value is 21000
+ milliseconds. Please note that this value is
+ adjusted to an arch timer tick resolution.
+ Setting this to zero causes the value from
+ rcupdate.rcu_cpu_stall_timeout to be used (after
+ conversion from seconds to milliseconds).
rcupdate.rcu_expedited= [KNL]
Use expedited grace-period primitives, for
@@ -4955,10 +4967,34 @@
number avoids disturbing real-time workloads,
but lengthens grace periods.
+ rcupdate.rcu_task_stall_info= [KNL]
+ Set initial timeout in jiffies for RCU task stall
+ informational messages, which give some indication
+ of the problem for those not patient enough to
+ wait for ten minutes. Informational messages are
+ only printed prior to the stall-warning message
+ for a given grace period. Disable with a value
+ less than or equal to zero. Defaults to ten
+ seconds. A change in value does not take effect
+ until the beginning of the next grace period.
+
+ rcupdate.rcu_task_stall_info_mult= [KNL]
+ Multiplier for time interval between successive
+ RCU task stall informational messages for a given
+ RCU tasks grace period. This value is clamped
+ to one through ten, inclusive. It defaults to
+ the value three, so that the first informational
+ message is printed 10 seconds into the grace
+ period, the second at 40 seconds, the third at
+ 160 seconds, and then the stall warning at 600
+ seconds would prevent a fourth at 640 seconds.
+
rcupdate.rcu_task_stall_timeout= [KNL]
- Set timeout in jiffies for RCU task stall warning
- messages. Disable with a value less than or equal
- to zero.
+ Set timeout in jiffies for RCU task stall
+ warning messages. Disable with a value less
+ than or equal to zero. Defaults to ten minutes.
+ A change in value does not take effect until
+ the beginning of the next grace period.
rcupdate.rcu_self_test= [KNL]
Run the RCU early boot self tests
@@ -5377,6 +5413,17 @@
smart2= [HW]
Format: <io1>[,<io2>[,...,<io8>]]
+ smp.csd_lock_timeout= [KNL]
+ Specify the period of time in milliseconds
+ that smp_call_function() and friends will wait
+ for a CPU to release the CSD lock. This is
+ useful when diagnosing bugs involving CPUs
+ disabling interrupts for extended periods
+ of time. Defaults to 5,000 milliseconds, and
+ setting a value of zero disables this feature.
+ This feature may be more efficiently disabled
+ using the csdlock_debug- kernel parameter.
+
smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
smsc-ircc2.ircc_sir= [HW] SIR base I/O port
@@ -5608,6 +5655,30 @@
off: Disable mitigation and remove
performance impact to RDRAND and RDSEED
+ srcutree.big_cpu_lim [KNL]
+ Specifies the number of CPUs constituting a
+ large system, such that srcu_struct structures
+ should immediately allocate an srcu_node array.
+ This kernel-boot parameter defaults to 128,
+ but takes effect only when the low-order four
+ bits of srcutree.convert_to_big is equal to 3
+ (decide at boot).
+
+ srcutree.convert_to_big [KNL]
+ Specifies under what conditions an SRCU tree
+ srcu_struct structure will be converted to big
+ form, that is, with an rcu_node tree:
+
+ 0: Never.
+ 1: At init_srcu_struct() time.
+ 2: When rcutorture decides to.
+ 3: Decide at boot time (default).
+ 0x1X: Above plus if high contention.
+
+ Either way, the srcu_node tree will be sized based
+ on the actual runtime number of CPUs (nr_cpu_ids)
+ instead of the compile-time CONFIG_NR_CPUS.
+
srcutree.counter_wrap_check [KNL]
Specifies how frequently to check for
grace-period sequence counter wrap for the
@@ -5625,6 +5696,14 @@
expediting. Set to zero to disable automatic
expediting.
+ srcutree.small_contention_lim [KNL]
+ Specifies the number of update-side contention
+ events per jiffy will be tolerated before
+ initiating a conversion of an srcu_struct
+ structure to big form. Note that the value of
+ srcutree.convert_to_big must have the 0x10 bit
+ set for contention-based conversions to occur.
+
ssbd= [ARM64,HW]
Speculative Store Bypass Disable control