aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/admin-guide/kernel-parameters.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt68
1 files changed, 56 insertions, 12 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 902ecd92a29fb..ef25e06ec08cc 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -431,6 +431,9 @@
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
Format: <io>,<irq>,<nodeID>
+ arm64.no32bit_el0 [ARM64] Unconditionally disable the execution of
+ 32 bit applications.
+
arm64.nobti [ARM64] Unconditionally disable Branch Target
Identification support
@@ -2148,6 +2151,12 @@
Format: 0 | 1
Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON.
+ init_mlocked_on_free= [MM] Fill freed userspace memory with zeroes if
+ it was mlock'ed and not explicitly munlock'ed
+ afterwards.
+ Format: 0 | 1
+ Default set by CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON
+
init_pkru= [X86] Specify the default memory protection keys rights
register contents for all processes. 0x55555554 by
default (disallow access to all but pkey 0). Can
@@ -2251,6 +2260,8 @@
no_x2apic_optout
BIOS x2APIC opt-out request will be ignored
nopost disable Interrupt Posting
+ posted_msi
+ enable MSIs delivered as posted interrupts
iomem= Disable strict checking of access to MMIO memory
strict regions from userspace.
@@ -3423,6 +3434,9 @@
arch-independent options, each of which is an
aggregation of existing arch-specific options.
+ Note, "mitigations" is supported if and only if the
+ kernel was built with CPU_MITIGATIONS=y.
+
off
Disable all optional CPU mitigations. This
improves system performance, but it may also
@@ -3773,10 +3787,12 @@
Format: [state][,regs][,debounce][,die]
nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
- Format: [panic,][nopanic,][num]
+ Format: [panic,][nopanic,][rNNN,][num]
Valid num: 0 or 1
0 - turn hardlockup detector in nmi_watchdog off
1 - turn hardlockup detector in nmi_watchdog on
+ rNNN - configure the watchdog with raw perf event 0xNNN
+
When panic is specified, panic when an NMI watchdog
timeout occurs (or 'nopanic' to not panic on an NMI
watchdog, if CONFIG_BOOTPARAM_HARDLOCKUP_PANIC is set)
@@ -4170,13 +4186,11 @@
page_alloc.shuffle=
[KNL] Boolean flag to control whether the page allocator
- should randomize its free lists. The randomization may
- be automatically enabled if the kernel detects it is
- running on a platform with a direct-mapped memory-side
- cache, and this parameter can be used to
- override/disable that behavior. The state of the flag
- can be read from sysfs at:
+ should randomize its free lists. This parameter can be
+ used to enable/disable page randomization. The state of
+ the flag can be read from sysfs at:
/sys/module/page_alloc/parameters/shuffle.
+ This parameter is only available if CONFIG_SHUFFLE_PAGE_ALLOCATOR=y.
page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
Storage of the information about who allocated
@@ -4591,9 +4605,10 @@
norid [S390] ignore the RID field and force use of
one PCI domain per PCI function
- pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
+ pcie_aspm= [PCIE] Forcibly enable or ignore PCIe Active State Power
Management.
- off Disable ASPM.
+ off Don't touch ASPM configuration at all. Leave any
+ configuration done by firmware unchanged.
force Enable ASPM even on devices that claim not to support it.
WARNING: Forcing ASPM on may cause system lockups.
@@ -4781,7 +4796,9 @@
prot_virt= [S390] enable hosting protected virtual machines
isolated from the hypervisor (if hardware supports
- that).
+ that). If enabled, the default kernel base address
+ might be overridden even when Kernel Address Space
+ Layout Randomization is disabled.
Format: <bool>
psi= [KNL] Enable or disable pressure stall information
@@ -5092,6 +5109,20 @@
delay, memory pressure or callback list growing too
big.
+ rcutree.rcu_normal_wake_from_gp= [KNL]
+ Reduces a latency of synchronize_rcu() call. This approach
+ maintains its own track of synchronize_rcu() callers, so it
+ does not interact with regular callbacks because it does not
+ use a call_rcu[_hurry]() path. Please note, this is for a
+ normal grace period.
+
+ How to enable it:
+
+ echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp
+ or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1"
+
+ Default is 0.
+
rcuscale.gp_async= [KNL]
Measure performance of asynchronous
grace-period primitives such as call_rcu().
@@ -5808,6 +5839,7 @@
but is useful for debugging and performance tuning.
sched_thermal_decay_shift=
+ [Deprecated]
[KNL, SMP] Set a decay shift for scheduler thermal
pressure signal. Thermal pressure signal follows the
default decay period of other scheduler pelt
@@ -6745,6 +6777,7 @@
- "tpm"
- "tee"
- "caam"
+ - "dcp"
If not specified then it defaults to iterating through
the trust source list starting with TPM and assigns the
first trust source as a backend which is initialized
@@ -6760,6 +6793,18 @@
If not specified, "default" is used. In this case,
the RNG's choice is left to each individual trust source.
+ trusted.dcp_use_otp_key
+ This is intended to be used in combination with
+ trusted.source=dcp and will select the DCP OTP key
+ instead of the DCP UNIQUE key blob encryption.
+
+ trusted.dcp_skip_zk_test
+ This is intended to be used in combination with
+ trusted.source=dcp and will disable the check if the
+ blob key is all zeros. This is helpful for situations where
+ having this key zero'ed is acceptable. E.g. in testing
+ scenarios.
+
tsc= Disable clocksource stability checks for TSC.
Format: <string>
[x86] reliable: mark tsc clocksource as reliable, this
@@ -7320,7 +7365,7 @@
This can be changed after boot by writing to the
matching /sys/module/workqueue/parameters file. All
workqueues with the "default" affinity scope will be
- updated accordignly.
+ updated accordingly.
workqueue.debug_force_rr_cpu
Workqueue used to implicitly guarantee that work
@@ -7464,4 +7509,3 @@
memory, and other data can't be written using
xmon commands.
off xmon is disabled.
-