aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/kernel-parameters.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt113
1 files changed, 105 insertions, 8 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7dbe5ec9d9cd..4df73da11adc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -829,6 +829,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
CONFIG_DEBUG_PAGEALLOC, hence this option will not help
tracking down these problems.
+ debug_pagealloc=
+ [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this
+ parameter enables the feature at boot time. In
+ default, it is disabled. We can avoid allocating huge
+ chunk of memory for debug pagealloc if we don't enable
+ it at boot time and the system will work mostly same
+ with the kernel built without CONFIG_DEBUG_PAGEALLOC.
+ on: enable the feature
+
debugpat [X86] Enable PAT debugging
decnet.addr= [HW,NET]
@@ -1015,10 +1024,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
Format: {"off" | "on" | "skip[mbr]"}
efi= [EFI]
- Format: { "old_map" }
+ Format: { "old_map", "nochunk", "noruntime" }
old_map [X86-64]: switch to the old ioremap-based EFI
runtime services mapping. 32-bit still uses this one by
default.
+ nochunk: disable reading files in "chunks" in the EFI
+ boot stub, as chunking can cause problems with some
+ firmware implementations.
+ noruntime : disable EFI runtime services support
efi_no_storage_paranoia [EFI; X86]
Using this parameter you can use more than 50% of
@@ -1224,9 +1237,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
multiple times interleaved with hugepages= to reserve
huge pages of different sizes. Valid pages sizes on
x86-64 are 2M (when the CPU supports "pse") and 1G
- (when the CPU supports the "pdpe1gb" cpuinfo flag)
- Note that 1GB pages can only be allocated at boot time
- using hugepages= and not freed afterwards.
+ (when the CPU supports the "pdpe1gb" cpuinfo flag).
hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
terminal devices. Valid values: 0..8
@@ -1260,7 +1271,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
i8042.noloop [HW] Disable the AUX Loopback command while probing
for the AUX port
i8042.nomux [HW] Don't check presence of an active multiplexing
- controller. Default: true.
+ controller
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
controllers
i8042.notimeout [HW] Ignore timeout condition signalled by controller
@@ -1303,6 +1314,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
.cdrom .chs .ignore_cable are additional options
See Documentation/ide/ide.txt.
+ ide-generic.probe-mask= [HW] (E)IDE subsystem
+ Format: <int>
+ Probe mask for legacy ISA IDE ports. Depending on
+ platform up to 6 ports are supported, enabled by
+ setting corresponding bits in the mask to 1. The
+ default value is 0x0, which has a special meaning.
+ On systems that have PCI, it triggers scanning the
+ PCI bus for the first and the second port, which
+ are then probed. On systems without PCI the value
+ of 0x0 enables probing the two first ports as if it
+ was 0x3.
+
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
Claim all unknown PCI IDE storage controllers.
@@ -1353,6 +1376,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
Formats: { "ima" | "ima-ng" }
Default: "ima-ng"
+ ima_template_fmt=
+ [IMA] Define a custom template format.
+ Format: { "field1|...|fieldN" }
+
ima.ahash_minsize= [IMA] Minimum file size for asynchronous hash usage
Format: <min_file_size>
Set the minimal file size for using asynchronous hash.
@@ -1430,6 +1457,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
disable
Do not enable intel_pstate as the default
scaling driver for the supported processors
+ force
+ Enable intel_pstate on systems that prohibit it by default
+ in favor of acpi-cpufreq. Forcing the intel_pstate driver
+ instead of acpi-cpufreq may disable platform features, such
+ as thermal controls and power capping, that rely on ACPI
+ P-States information being indicated to OSPM and therefore
+ should be used with caution. This option does not work with
+ processors that aren't supported by the intel_pstate driver
+ or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
+ no_hwp
+ Do not enable hardware P state control (HWP)
+ if available.
intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
@@ -1583,6 +1622,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
kmemleak= [KNL] Boot-time kmemleak enable/disable
Valid arguments: on, off
Default: on
+ Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
+ the default is off.
kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode
Valid arguments: 0, 1, 2
@@ -2232,7 +2273,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
nodsp [SH] Disable hardware DSP at boot time.
- noefi [X86] Disable EFI runtime services support.
+ noefi Disable EFI runtime services support.
noexec [IA-64]
@@ -2485,12 +2526,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
OSS [HW,OSS]
See Documentation/sound/oss/oss-parameters.txt
+ page_owner= [KNL] Boot-time page_owner enabling option.
+ Storage of the information about who allocated
+ each page is disabled in default. With this switch,
+ we can turn it on.
+ on: enable the feature
+
panic= [KNL] Kernel behaviour on panic: delay <timeout>
timeout > 0: seconds before rebooting
timeout = 0: wait forever
timeout < 0: reboot immediately
Format: <timeout>
+ panic_on_warn panic() instead of WARN(). Useful to cause kdump
+ on a WARN().
+
crash_kexec_post_notifiers
Run kdump after running panic-notifiers and dumping
kmsg. This only for the users who doubt kdump always
@@ -2922,6 +2972,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
quiescent states. Units are jiffies, minimum
value is one, and maximum value is HZ.
+ rcutree.kthread_prio= [KNL,BOOT]
+ Set the SCHED_FIFO priority of the RCU
+ per-CPU kthreads (rcuc/N). This value is also
+ used for the priority of the RCU boost threads
+ (rcub/N). Valid values are 1-99 and the default
+ is 1 (the least-favored priority).
+
rcutree.rcu_nocb_leader_stride= [KNL]
Set the number of NOCB kthread groups, which
defaults to the square root of the number of
@@ -3071,6 +3128,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
messages. Disable with a value less than or equal
to zero.
+ rcupdate.rcu_self_test= [KNL]
+ Run the RCU early boot self tests
+
+ rcupdate.rcu_self_test_bh= [KNL]
+ Run the RCU bh early boot self tests
+
+ rcupdate.rcu_self_test_sched= [KNL]
+ Run the RCU sched early boot self tests
+
rdinit= [KNL]
Format: <full_path>
Run specified binary instead of /init from the ramdisk,
@@ -3394,6 +3460,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
neutralize any effect of /proc/sys/kernel/sysrq.
Useful for debugging.
+ tcpmhash_entries= [KNL,NET]
+ Set the number of tcp_metrics_hash slots.
+ Default value is 8192 or 16384 depending on total
+ ram pages. This is used to specify the TCP metrics
+ cache size. See Documentation/networking/ip-sysctl.txt
+ "tcp_no_metrics_save" section for more details.
+
tdfx= [HW,DRM]
test_suspend= [SUSPEND][,N]
@@ -3465,6 +3538,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
e.g. base its process migration decisions on it.
Default is on.
+ topology_updates= [KNL, PPC, NUMA]
+ Format: {off}
+ Specify if the kernel should ignore (off)
+ topology updates sent by the hypervisor to this
+ LPAR.
+
tp720= [HW,PS2]
tpm_suspend_pcr=[HW,TPM]
@@ -3477,7 +3556,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
are saved.
trace_buf_size=nn[KMG]
- [FTRACE] will set tracing buffer size.
+ [FTRACE] will set tracing buffer size on each cpu.
trace_event=[event-list]
[FTRACE] Set and start specified trace events in order
@@ -3500,6 +3579,24 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
See also Documentation/trace/ftrace.txt "trace options"
section.
+ tp_printk[FTRACE]
+ Have the tracepoints sent to printk as well as the
+ tracing ring buffer. This is useful for early boot up
+ where the system hangs or reboots and does not give the
+ option for reading the tracing buffer or performing a
+ ftrace_dump_on_oops.
+
+ To turn off having tracepoints sent to printk,
+ echo 0 > /proc/sys/kernel/tracepoint_printk
+ Note, echoing 1 into this file without the
+ tracepoint_printk kernel cmdline option has no effect.
+
+ ** CAUTION **
+
+ Having tracepoints sent to printk() and activating high
+ frequency tracepoints such as irq or sched, can cause
+ the system to live lock.
+
traceoff_on_warning
[FTRACE] enable this option to disable tracing when a
warning is hit. This turns off "tracing_on". Tracing can
@@ -3597,7 +3694,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
usb-storage.delay_use=
[UMS] The delay in seconds before a new device is
- scanned for Logical Units (default 5).
+ scanned for Logical Units (default 1).
usb-storage.quirks=
[UMS] A list of quirks entries to supplement or