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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt97
1 files changed, 70 insertions, 27 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index b799bcf67d7b..2b8ee90bb644 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -461,6 +461,11 @@
possible to determine what the correct size should be.
This option provides an override for these situations.
+ carrier_timeout=
+ [NET] Specifies amount of time (in seconds) that
+ the kernel should wait for a network carrier. By default
+ it waits 120 seconds.
+
ca_keys= [KEYS] This parameter identifies a specific key(s) on
the system trusted keyring to be used for certificate
trust validation.
@@ -910,6 +915,10 @@
The filter can be disabled or changed to another
driver later using sysfs.
+ driver_async_probe= [KNL]
+ List of driver names to be probed asynchronously.
+ Format: <driver_name1>,<driver_name2>...
+
drm.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
Broken monitors, graphic adapters, KVMs and EDIDless
panels may send no or incorrect EDID data sets.
@@ -1073,9 +1082,15 @@
specified address. The serial port must already be
setup and configured. Options are not yet supported.
+ efifb,[options]
+ Start an early, unaccelerated console on the EFI
+ memory mapped framebuffer (if available). On cache
+ coherent non-x86 systems that use system memory for
+ the framebuffer, pass the 'ram' option so that it is
+ mapped with the correct attributes.
+
earlyprintk= [X86,SH,ARM,M68k,S390]
earlyprintk=vga
- earlyprintk=efi
earlyprintk=sclp
earlyprintk=xen
earlyprintk=serial[,ttySn[,baudrate]]
@@ -1182,9 +1197,10 @@
arch/x86/kernel/cpu/cpufreq/elanfreq.c.
elevator= [IOSCHED]
- Format: {"cfq" | "deadline" | "noop"}
- See Documentation/block/cfq-iosched.txt and
- Documentation/block/deadline-iosched.txt for details.
+ Format: { "mq-deadline" | "kyber" | "bfq" }
+ See Documentation/block/deadline-iosched.txt,
+ Documentation/block/kyber-iosched.txt and
+ Documentation/block/bfq-iosched.txt for details.
elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390]
Specifies physical address of start of kernel core
@@ -1696,12 +1712,11 @@
By default, super page will be supported if Intel IOMMU
has the capability. With this option, super page will
not be supported.
- sm_off [Default Off]
- By default, scalable mode will be supported if the
+ sm_on [Default Off]
+ By default, scalable mode will be disabled even if the
hardware advertises that it has support for the scalable
mode translation. With this option set, scalable mode
- will not be used even on hardware which claims to support
- it.
+ will be used on hardware which claims to support it.
tboot_noforce [Default Off]
Do not force the Intel IOMMU enabled under tboot.
By default, tboot will force Intel IOMMU on, which
@@ -1831,6 +1846,11 @@
to let secondary kernels in charge of setting up
LPIs.
+ irqchip.gicv3_pseudo_nmi= [ARM64]
+ Enables support for pseudo-NMIs in the kernel. This
+ requires the kernel to be built with
+ CONFIG_ARM64_PSEUDO_NMI.
+
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
@@ -1982,6 +2002,12 @@
Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
the default is off.
+ kpti= [ARM64] Control page table isolation of user
+ and kernel address spaces.
+ Default: enabled on cores which need mitigation.
+ 0: force disabled
+ 1: force enabled
+
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
Default is 0 (don't ignore, but inject #GP)
@@ -2319,6 +2345,10 @@
lsm.debug [SECURITY] Enable LSM initialization debugging output.
+ lsm=lsm1,...,lsmN
+ [SECURITY] Choose order of LSM initialization. This
+ overrides CONFIG_LSM, and the "security=" parameter.
+
machvec= [IA-64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
@@ -3654,19 +3684,6 @@
latencies, which will choose a value aligned
with the appropriate hardware boundaries.
- rcutree.jiffies_till_sched_qs= [KNL]
- Set required age in jiffies for a
- given grace period before RCU starts
- soliciting quiescent-state help from
- rcu_note_context_switch(). If not specified, the
- kernel will calculate a value based on the most
- recent settings of rcutree.jiffies_till_first_fqs
- and rcutree.jiffies_till_next_fqs.
- This calculated value may be viewed in
- rcutree.jiffies_to_sched_qs. Any attempt to
- set rcutree.jiffies_to_sched_qs will be
- cheerfully overwritten.
-
rcutree.jiffies_till_first_fqs= [KNL]
Set delay from grace-period initialization to
first attempt to force quiescent states.
@@ -3678,6 +3695,20 @@
quiescent states. Units are jiffies, minimum
value is one, and maximum value is HZ.
+ rcutree.jiffies_till_sched_qs= [KNL]
+ Set required age in jiffies for a
+ given grace period before RCU starts
+ soliciting quiescent-state help from
+ rcu_note_context_switch() and cond_resched().
+ If not specified, the kernel will calculate
+ a value based on the most recent settings
+ of rcutree.jiffies_till_first_fqs
+ and rcutree.jiffies_till_next_fqs.
+ This calculated value may be viewed in
+ rcutree.jiffies_to_sched_qs. Any attempt to set
+ rcutree.jiffies_to_sched_qs will be cheerfully
+ overwritten.
+
rcutree.kthread_prio= [KNL,BOOT]
Set the SCHED_FIFO priority of the RCU per-CPU
kthreads (rcuc/N). This value is also used for
@@ -3721,6 +3752,11 @@
This wake_up() will be accompanied by a
WARN_ONCE() splat and an ftrace_dump().
+ rcutree.sysrq_rcu= [KNL]
+ Commandeer a sysrq key to dump out Tree RCU's
+ rcu_node tree with an eye towards determining
+ why a new grace period has not yet started.
+
rcuperf.gp_async= [KNL]
Measure performance of asynchronous
grace-period primitives such as call_rcu().
@@ -4090,11 +4126,9 @@
Note: increases power consumption, thus should only be
enabled if running jitter sensitive (HPC/RT) workloads.
- security= [SECURITY] Choose a security module to enable at boot.
- If this boot parameter is not specified, only the first
- security module asking for security registration will be
- loaded. An invalid security module name will be treated
- as if no module has been chosen.
+ security= [SECURITY] Choose a legacy "major" security module to
+ enable at boot. This has been deprecated by the
+ "lsm=" parameter.
selinux= [SELINUX] Disable or enable SELinux at boot time.
Format: { "0" | "1" }
@@ -4698,7 +4732,8 @@
usbcore.authorized_default=
[USB] Default USB device authorization:
(default -1 = authorized except for wireless USB,
- 0 = not authorized, 1 = authorized)
+ 0 = not authorized, 1 = authorized, 2 = authorized
+ if device connected to internal port)
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
@@ -5043,6 +5078,14 @@
or other driver-specific files in the
Documentation/watchdog/ directory.
+ watchdog_thresh=
+ [KNL]
+ Set the hard lockup detector stall duration
+ threshold in seconds. The soft lockup detector
+ threshold is set to twice the value. A value of 0
+ disables both lockup detectors. Default is 10
+ seconds.
+
workqueue.watchdog_thresh=
If CONFIG_WQ_WATCHDOG is configured, workqueue can
warn stall conditions and dump internal state to