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-rw-r--r--Documentation/kernel-parameters.txt147
1 files changed, 132 insertions, 15 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a92c5eb..6c72381 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -446,12 +446,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
possible to determine what the correct size should be.
This option provides an override for these situations.
- capability.disable=
- [SECURITY] Disable capabilities. This would normally
- be used only if an alternative security model is to be
- configured. Potentially dangerous and should only be
- used if you are entirely sure of the consequences.
-
ccw_timeout_log [S390]
See Documentation/s390/CommonIO for details.
@@ -526,7 +520,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
coherent_pool=nn[KMG] [ARM,KNL]
Sets the size of memory pool for coherent, atomic dma
- allocations if Contiguous Memory Allocator (CMA) is used.
+ allocations, by default set to 256K.
code_bytes [X86] How many bytes of object code to print
in an oops report.
@@ -905,6 +899,24 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
gpt [EFI] Forces disk with valid GPT signature but
invalid Protective MBR to be treated as GPT.
+ grcan.enable0= [HW] Configuration of physical interface 0. Determines
+ the "Enable 0" bit of the configuration register.
+ Format: 0 | 1
+ Default: 0
+ grcan.enable1= [HW] Configuration of physical interface 1. Determines
+ the "Enable 0" bit of the configuration register.
+ Format: 0 | 1
+ Default: 0
+ grcan.select= [HW] Select which physical interface to use.
+ Format: 0 | 1
+ Default: 0
+ grcan.txsize= [HW] Sets the size of the tx buffer.
+ Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0.
+ Default: 1024
+ grcan.rxsize= [HW] Sets the size of the rx buffer.
+ Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0.
+ Default: 1024
+
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
for 64-bit NUMA, off otherwise.
@@ -1051,6 +1063,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
+ ima_appraise= [IMA] appraise integrity measurements
+ Format: { "off" | "enforce" | "fix" }
+ default: "enforce"
+
+ ima_appraise_tcb [IMA]
+ The builtin appraise policy appraises all files
+ owned by uid=0.
+
ima_audit= [IMA]
Format: { "0" | "1" }
0 -- integrity auditing messages. (Default)
@@ -1134,7 +1154,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
forcesac
soft
pt [x86, IA-64]
- group_mf [x86, IA-64]
io7= [HW] IO7 for Marvel based alpha systems
@@ -1297,6 +1316,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
+ lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline
+ value for LAPIC timer one-shot implementation. Default
+ back to the programmable timer unit in the LAPIC.
+
lapic_timer_c2_ok [X86,APIC] trust the local apic timer
in C2 power state.
@@ -1351,6 +1374,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
* nohrst, nosrst, norst: suppress hard, soft
and both resets.
+ * rstonce: only attempt one reset during
+ hot-unplug link recovery
+
* dump_id: dump IDENTIFY data.
If there are multiple matching configurations changing
@@ -1471,9 +1497,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
Amount of memory to be used when the kernel is not able
to see the whole system memory or for test.
- [X86-32] Use together with memmap= to avoid physical
- address space collisions. Without memmap= PCI devices
- could be placed at addresses belonging to unused RAM.
+ [X86] Work as limiting max address. Use together
+ with memmap= to avoid physical address space collisions.
+ Without memmap= PCI devices could be placed at addresses
+ belonging to unused RAM.
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.
@@ -1583,6 +1610,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
log everything. Information is printed at KERN_DEBUG
so loglevel=8 may also need to be specified.
+ module.sig_enforce
+ [KNL] When CONFIG_MODULE_SIG is set, this means that
+ modules without (valid) signatures will fail to load.
+ Note that if CONFIG_MODULE_SIG_ENFORCE is set, that
+ is always true, so this option does nothing.
+
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
@@ -1720,6 +1753,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
will be autodetected by the client, and it will fall
back to using the idmapper.
To turn off this behaviour, set the value to '0'.
+ nfs.nfs4_unique_id=
+ [NFS4] Specify an additional fixed unique ident-
+ ification string that NFSv4 clients can insert into
+ their nfs_client_id4 string. This is typically a
+ UUID that is generated at system install time.
nfs.send_implementation_id =
[NFSv4.1] Send client implementation identification
@@ -1813,8 +1851,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
noexec=on: enable non-executable mappings (default)
noexec=off: disable non-executable mappings
+ nosmap [X86]
+ Disable SMAP (Supervisor Mode Access Prevention)
+ even if it is supported by processor.
+
nosmep [X86]
- Disable SMEP (Supervisor Mode Execution Protection)
+ Disable SMEP (Supervisor Mode Execution Prevention)
even if it is supported by processor.
noexec32 [X86-64]
@@ -1834,6 +1876,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
and restore using xsave. The kernel will fallback to
enabling legacy floating-point and sse state.
+ eagerfpu= [X86]
+ on enable eager fpu restore
+ off disable eager fpu restore
+ auto selects the default scheme, which automatically
+ enables eagerfpu restore for xsaveopt.
+
nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
wfi(ARM) instruction doesn't work correctly and not to
use it. This is also useful when using JTAG debugger.
@@ -1953,6 +2001,20 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
+ cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
+ CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off.
+ Some features depend on CPU0. Known dependencies are:
+ 1. Resume from suspend/hibernate depends on CPU0.
+ Suspend/hibernate will fail if CPU0 is offline and you
+ need to online CPU0 before suspend/hibernate.
+ 2. PIC interrupts also depend on CPU0. CPU0 can't be
+ removed if a PIC interrupt is detected.
+ It's said poweroff/reboot may depend on CPU0 on some
+ machines although I haven't seen such issues so far
+ after CPU0 is offline on a few tested machines.
+ If the dependencies are under your control, you can
+ turn on cpu0_hotplug.
+
nptcg= [IA-64] Override max number of concurrent global TLB
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
@@ -1965,6 +2027,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
+ numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing.
+ Allowed values are enable and disable
+
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
one of ['zone', 'node', 'default'] can be specified
This can be set from sysctl after boot.
@@ -2363,10 +2428,36 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
See Documentation/blockdev/ramdisk.txt.
+ rcu_nocbs= [KNL,BOOT]
+ In kernels built with CONFIG_RCU_NOCB_CPU=y, set
+ the specified list of CPUs to be no-callback CPUs.
+ Invocation of these CPUs' RCU callbacks will
+ be offloaded to "rcuoN" kthreads created for
+ that purpose. This reduces OS jitter on the
+ offloaded CPUs, which can be useful for HPC and
+ real-time workloads. It can also improve energy
+ efficiency for asymmetric multiprocessors.
+
+ rcu_nocb_poll [KNL,BOOT]
+ Rather than requiring that offloaded CPUs
+ (specified by rcu_nocbs= above) explicitly
+ awaken the corresponding "rcuoN" kthreads,
+ make these kthreads poll for callbacks.
+ This improves the real-time response for the
+ offloaded CPUs by relieving them of the need to
+ wake up the corresponding kthread, but degrades
+ energy efficiency by requiring that the kthreads
+ periodically wake up to do the polling.
+
rcutree.blimit= [KNL,BOOT]
Set maximum number of finished RCU callbacks to process
in one batch.
+ rcutree.fanout_leaf= [KNL,BOOT]
+ Increase the number of CPUs assigned to each
+ leaf rcu_node structure. Useful for very large
+ systems.
+
rcutree.qhimark= [KNL,BOOT]
Set threshold of queued
RCU callbacks over which batch limiting is disabled.
@@ -2381,6 +2472,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
rcutree.rcu_cpu_stall_timeout= [KNL,BOOT]
Set timeout for RCU CPU stall warning messages.
+ rcutree.jiffies_till_first_fqs= [KNL,BOOT]
+ Set delay from grace-period initialization to
+ first attempt to force quiescent states.
+ Units are jiffies, minimum value is zero,
+ and maximum value is HZ.
+
+ rcutree.jiffies_till_next_fqs= [KNL,BOOT]
+ Set delay between subsequent attempts to force
+ quiescent states. Units are jiffies, minimum
+ value is one, and maximum value is HZ.
+
rcutorture.fqs_duration= [KNL,BOOT]
Set duration of force_quiescent_state bursts.
@@ -2634,9 +2736,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
smart2= [HW]
Format: <io1>[,<io2>[,...,<io8>]]
- smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
- attempt to substitute SMP alternatives once at boot.
-
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
@@ -2815,6 +2914,22 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
to facilitate early boot debugging.
See also Documentation/trace/events.txt
+ trace_options=[option-list]
+ [FTRACE] Enable or disable tracer options at boot.
+ The option-list is a comma delimited list of options
+ that can be enabled or disabled just as if you were
+ to echo the option name into
+
+ /sys/kernel/debug/tracing/trace_options
+
+ For example, to enable stacktrace option (to dump the
+ stack trace of each event), add to the command line:
+
+ trace_options=stacktrace
+
+ See also Documentation/trace/ftrace.txt "trace options"
+ section.
+
transparent_hugepage=
[KNL]
Format: [always|madvise|never]
@@ -2932,6 +3047,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
initial READ(10) command);
o = CAPACITY_OK (accept the capacity
reported by the device);
+ p = WRITE_CACHE (the device cache is ON
+ by default);
r = IGNORE_RESIDUE (the device reports
bogus residue values);
s = SINGLE_LUN (the device has only one