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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt118
1 files changed, 94 insertions, 24 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index f2a93c8679e8..f3eeecbb3f63 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -356,7 +356,7 @@
shot down by NMI
autoconf= [IPV6]
- See Documentation/networking/ipv6.txt.
+ See Documentation/networking/ipv6.rst.
show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
Limit apic dumping. The parameter defines the maximal
@@ -458,7 +458,7 @@
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
kernel args too.
- bttv.pll= See Documentation/media/v4l-drivers/bttv.rst
+ bttv.pll= See Documentation/admin-guide/media/bttv.rst
bttv.tuner=
bulk_remove=off [PPC] This parameter disables the use of the pSeries
@@ -638,7 +638,7 @@
See Documentation/admin-guide/serial-console.rst for more
information. See
- Documentation/networking/netconsole.txt for an
+ Documentation/networking/netconsole.rst for an
alternative.
uart[8250],io,<addr>[,options]
@@ -831,15 +831,18 @@
decnet.addr= [HW,NET]
Format: <area>[,<node>]
- See also Documentation/networking/decnet.txt.
+ See also Documentation/networking/decnet.rst.
default_hugepagesz=
- [same as hugepagesz=] The size of the default
- HugeTLB page size. This is the size represented by
- the legacy /proc/ hugepages APIs, used for SHM, and
- default size when mounting hugetlbfs filesystems.
- Defaults to the default architecture's huge page size
- if not specified.
+ [HW] The size of the default HugeTLB page. This is
+ the size represented by the legacy /proc/ hugepages
+ APIs. In addition, this is the default hugetlb size
+ used for shmget(), mmap() and mounting hugetlbfs
+ filesystems. If not specified, defaults to the
+ architecture's default huge page size. Huge page
+ sizes are architecture dependent. See also
+ Documentation/admin-guide/mm/hugetlbpage.rst.
+ Format: size[KMG]
deferred_probe_timeout=
[KNL] Debugging option to set a timeout in seconds for
@@ -871,8 +874,13 @@
can be useful when debugging issues that require an SLB
miss to occur.
+ stress_slb [PPC]
+ Limits the number of kernel SLB entries, and flushes
+ them frequently to increase the rate of SLB faults
+ on kernel addresses.
+
disable= [IPV6]
- See Documentation/networking/ipv6.txt.
+ See Documentation/networking/ipv6.rst.
hardened_usercopy=
[KNL] Under CONFIG_HARDENED_USERCOPY, whether
@@ -912,7 +920,7 @@
to workaround buggy firmware.
disable_ipv6= [IPV6]
- See Documentation/networking/ipv6.txt.
+ See Documentation/networking/ipv6.rst.
disable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
@@ -1190,6 +1198,11 @@
This is designed to be used in conjunction with
the boot argument: earlyprintk=vga
+ This parameter works in place of the kgdboc parameter
+ but can only be used if the backing tty is available
+ very early in the boot process. For early debugging
+ via a serial port see kgdboc_earlycon instead.
+
edd= [EDD]
Format: {"off" | "on" | "skip[mbr]"}
@@ -1479,13 +1492,24 @@
hugepages using the cma allocator. If enabled, the
boot-time allocation of gigantic hugepages is skipped.
- hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
- hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
- On x86-64 and powerpc, this option can be specified
- 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).
+ hugepages= [HW] Number of HugeTLB pages to allocate at boot.
+ If this follows hugepagesz (below), it specifies
+ the number of pages of hugepagesz to be allocated.
+ If this is the first HugeTLB parameter on the command
+ line, it specifies the number of pages to allocate for
+ the default huge page size. See also
+ Documentation/admin-guide/mm/hugetlbpage.rst.
+ Format: <integer>
+
+ hugepagesz=
+ [HW] The size of the HugeTLB pages. This is used in
+ conjunction with hugepages (above) to allocate huge
+ pages of a specific size at boot. The pair
+ hugepagesz=X hugepages=Y can be specified once for
+ each supported huge page size. Huge page sizes are
+ architecture dependent. See also
+ Documentation/admin-guide/mm/hugetlbpage.rst.
+ Format: size[KMG]
hung_task_panic=
[KNL] Should the hung task detector generate panics.
@@ -1748,6 +1772,13 @@
initrd= [BOOT] Specify the location of the initial ramdisk
+ initrdmem= [KNL] Specify a physical address and size from which to
+ load the initrd. If an initrd is compiled in or
+ specified in the bootparams, it takes priority over this
+ setting.
+ Format: ss[KMG],nn[KMG]
+ Default is 0, 0
+
init_on_alloc= [MM] Fill newly allocated pages and heap objects with
zeroes.
Format: 0 | 1
@@ -2105,6 +2136,21 @@
kms, kbd format: kms,kbd
kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]
+ kgdboc_earlycon= [KGDB,HW]
+ If the boot console provides the ability to read
+ characters and can work in polling mode, you can use
+ this parameter to tell kgdb to use it as a backend
+ until the normal console is registered. Intended to
+ be used together with the kgdboc parameter which
+ specifies the normal console to transition to.
+
+ The name of the early console should be specified
+ as the value of this parameter. Note that the name of
+ the early console might be different than the tty
+ name passed to kgdboc. It's OK to leave the value
+ blank and the first boot console that implements
+ read() will be picked.
+
kgdbwait [KGDB] Stop kernel execution and enter the
kernel debugger at the earliest opportunity.
@@ -2705,7 +2751,7 @@
See Documentation/admin-guide/pm/sleep-states.rst.
meye.*= [HW] Set MotionEye Camera parameters
- See Documentation/media/v4l-drivers/meye.rst.
+ See Documentation/admin-guide/media/meye.rst.
mfgpt_irq= [IA-32] Specify the IRQ to use for the
Multi-Function General Purpose Timers on AMD Geode
@@ -3329,7 +3375,7 @@
See Documentation/admin-guide/sysctl/vm.rst for details.
ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
- See Documentation/debugging-via-ohci1394.txt for more
+ See Documentation/core-api/debugging-via-ohci1394.rst for more
info.
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
@@ -4210,12 +4256,24 @@
Duration of CPU stall (s) to test RCU CPU stall
warnings, zero to disable.
+ rcutorture.stall_cpu_block= [KNL]
+ Sleep while stalling if set. This will result
+ in warnings from preemptible RCU in addition
+ to any other stall-related activity.
+
rcutorture.stall_cpu_holdoff= [KNL]
Time to wait (s) after boot before inducing stall.
rcutorture.stall_cpu_irqsoff= [KNL]
Disable interrupts while stalling if set.
+ rcutorture.stall_gp_kthread= [KNL]
+ Duration (s) of forced sleep within RCU
+ grace-period kthread to test RCU CPU stall
+ warnings, zero to disable. If both stall_cpu
+ and stall_gp_kthread are specified, the
+ kthread is starved first, then the CPU.
+
rcutorture.stat_interval= [KNL]
Time (s) between statistics printk()s.
@@ -4286,6 +4344,13 @@
only normal grace-period primitives. No effect
on CONFIG_TINY_RCU kernels.
+ rcupdate.rcu_task_ipi_delay= [KNL]
+ Set time in jiffies during which RCU tasks will
+ avoid sending IPIs, starting with the beginning
+ of a given grace period. Setting a large
+ number avoids disturbing real-time workloads,
+ but lengthens grace periods.
+
rcupdate.rcu_task_stall_timeout= [KNL]
Set timeout in jiffies for RCU task stall warning
messages. Disable with a value less than or equal
@@ -4910,7 +4975,7 @@
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
+ cache size. See Documentation/networking/ip-sysctl.rst
"tcp_no_metrics_save" section for more details.
tdfx= [HW,DRM]
@@ -5067,6 +5132,12 @@
interruptions from clocksource watchdog are not
acceptable).
+ tsc_early_khz= [X86] Skip early TSC calibration and use the given
+ value instead. Useful when the early TSC frequency discovery
+ procedure is not reliable, such as on overclocked systems
+ with CPUID.16h support and partial CPUID.15h support.
+ Format: <unsigned int>
+
tsx= [X86] Control Transactional Synchronization
Extensions (TSX) feature in Intel processors that
support TSX control.
@@ -5187,8 +5258,7 @@
usbcore.old_scheme_first=
[USB] Start with the old device initialization
- scheme, applies only to low and full-speed devices
- (default 0 = off).
+ scheme (default 0 = off).
usbcore.usbfs_memory_mb=
[USB] Memory limit (in MB) for buffers allocated by