diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 168 |
1 files changed, 117 insertions, 51 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index aefd358a5ca3..2b8ee90bb644 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -331,7 +331,7 @@ APC and your system crashes randomly. apic= [APIC,X86] Advanced Programmable Interrupt Controller - Change the output verbosity whilst booting + Change the output verbosity while booting Format: { quiet (default) | verbose | debug } Change the amount of debugging information output when initialising the APIC and IO-APIC components. @@ -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. @@ -486,10 +491,14 @@ cut the overhead, others just disable the usage. So only cgroup_disable=memory is actually worthy} - cgroup_no_v1= [KNL] Disable one, multiple, all cgroup controllers in v1 - Format: { controller[,controller...] | "all" } + cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1 + Format: { { controller | "all" | "named" } + [,{ controller | "all" | "named" }...] } Like cgroup_disable, but only applies to cgroup v1; the blacklisted controllers remain available in cgroup2. + "all" blacklists all controllers and "named" disables + named mounts. Specifying both "all" and "named" disables + all v1 hierarchies. cgroup.memory= [KNL] Pass options to the cgroup memory controller. Format: <string> @@ -674,6 +683,9 @@ cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system + cpuidle.governor= + [CPU_IDLE] Name of the cpuidle governor to use. + cpufreq.off=1 [CPU_FREQ] disable the cpufreq sub-system @@ -903,6 +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. @@ -1021,6 +1037,12 @@ specified address. The serial port must already be setup and configured. Options are not yet supported. + rda,<addr> + Start an early, polled-mode console on a serial port + of an RDA Micro SoC, such as RDA8810PL, at the + specified address. The serial port must already be + setup and configured. Options are not yet supported. + smh Use ARM semihosting calls for early console. s3c2410,<addr> @@ -1060,9 +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]] @@ -1169,9 +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 @@ -1683,12 +1712,11 @@ By default, super page will be supported if Intel IOMMU has the capability. With this option, super page will not be supported. - ecs_off [Default Off] - By default, extended context tables will be supported if - the hardware advertises that it has support both for the - extended tables themselves, and also PASID support. With - this option set, extended tables will not be used even - on hardware which claims to support them. + 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 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 @@ -1818,6 +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 @@ -1969,6 +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) @@ -2096,6 +2135,9 @@ off Disables hypervisor mitigations and doesn't emit any warnings. + It also drops the swap size and available + RAM limit restriction on both hypervisor and + bare metal. Default is 'flush'. @@ -2303,6 +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 @@ -2827,7 +2873,7 @@ check bypass). With this option data leaks are possible in the system. - nospectre_v2 [X86] Disable all mitigations for the Spectre variant 2 + nospectre_v2 [X86,PPC_FSL_BOOK3E] Disable all mitigations for the Spectre variant 2 (indirect branch prediction) vulnerability. System may allow data leaks with this option, which is equivalent to spectre_v2=off. @@ -3082,6 +3128,14 @@ timeout < 0: reboot immediately Format: <timeout> + panic_print= Bitmask for printing system info when panic happens. + User can chose combination of the following bits: + bit 0: print all tasks info + bit 1: print system memory info + bit 2: print timer info + bit 3: print locks info if CONFIG_LOCKDEP is on + bit 4: print ftrace buffer + panic_on_warn panic() instead of WARN(). Useful to cause kdump on a WARN(). @@ -3630,19 +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. @@ -3654,6 +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 @@ -3697,6 +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(). @@ -3748,24 +3808,6 @@ in microseconds. The default of zero says no holdoff. - rcutorture.cbflood_inter_holdoff= [KNL] - Set holdoff time (jiffies) between successive - callback-flood tests. - - rcutorture.cbflood_intra_holdoff= [KNL] - Set holdoff time (jiffies) between successive - bursts of callbacks within a given callback-flood - test. - - rcutorture.cbflood_n_burst= [KNL] - Set the number of bursts making up a given - callback-flood test. Set this to zero to - disable callback-flood testing. - - rcutorture.cbflood_n_per_burst= [KNL] - Set the number of callbacks to be registered - in a given burst of a callback-flood test. - rcutorture.fqs_duration= [KNL] Set duration of force_quiescent_state bursts in microseconds. @@ -3778,6 +3820,23 @@ Set wait time between force_quiescent_state bursts in seconds. + rcutorture.fwd_progress= [KNL] + Enable RCU grace-period forward-progress testing + for the types of RCU supporting this notion. + + rcutorture.fwd_progress_div= [KNL] + Specify the fraction of a CPU-stall-warning + period to do tight-loop forward-progress testing. + + rcutorture.fwd_progress_holdoff= [KNL] + Number of seconds to wait between successive + forward-progress tests. + + rcutorture.fwd_progress_need_resched= [KNL] + Enclose cond_resched() calls within checks for + need_resched() during tight-loop forward-progress + testing. + rcutorture.gp_cond= [KNL] Use conditional/asynchronous update-side primitives, if available. @@ -4067,11 +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" } @@ -4675,7 +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 @@ -5020,6 +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 |