diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 96 |
1 files changed, 80 insertions, 16 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 479ff1737c2f..45d95614ec44 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -431,6 +431,9 @@ arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards Format: <io>,<irq>,<nodeID> + arm64.no32bit_el0 [ARM64] Unconditionally disable the execution of + 32 bit applications. + arm64.nobti [ARM64] Unconditionally disable Branch Target Identification support @@ -1572,12 +1575,28 @@ The above will cause the "foo" tracing instance to trigger a snapshot at the end of boot up. - ftrace_dump_on_oops[=orig_cpu] + ftrace_dump_on_oops[=2(orig_cpu) | =<instance>][,<instance> | + ,<instance>=2(orig_cpu)] [FTRACE] will dump the trace buffers on oops. - If no parameter is passed, ftrace will dump - buffers of all CPUs, but if you pass orig_cpu, it will - dump only the buffer of the CPU that triggered the - oops. + If no parameter is passed, ftrace will dump global + buffers of all CPUs, if you pass 2 or orig_cpu, it + will dump only the buffer of the CPU that triggered + the oops, or the specific instance will be dumped if + its name is passed. Multiple instance dump is also + supported, and instances are separated by commas. Each + instance supports only dump on CPU that triggered the + oops by passing 2 or orig_cpu to it. + + ftrace_dump_on_oops=foo=orig_cpu + + The above will dump only the buffer of "foo" instance + on CPU that triggered the oops. + + ftrace_dump_on_oops,foo,bar=orig_cpu + + The above will dump global buffer on all CPUs, the + buffer of "foo" instance on all CPUs and the buffer + of "bar" instance on CPU that triggered the oops. ftrace_filter=[function-list] [FTRACE] Limit the functions traced by the function @@ -2235,6 +2254,8 @@ no_x2apic_optout BIOS x2APIC opt-out request will be ignored nopost disable Interrupt Posting + posted_msi + enable MSIs delivered as posted interrupts iomem= Disable strict checking of access to MMIO memory strict regions from userspace. @@ -3407,6 +3428,9 @@ arch-independent options, each of which is an aggregation of existing arch-specific options. + Note, "mitigations" is supported if and only if the + kernel was built with CPU_MITIGATIONS=y. + off Disable all optional CPU mitigations. This improves system performance, but it may also @@ -3428,6 +3452,7 @@ retbleed=off [X86] spec_rstack_overflow=off [X86] spec_store_bypass_disable=off [X86,PPC] + spectre_bhi=off [X86] spectre_v2_user=off [X86] srbds=off [X86,INTEL] ssbd=force-off [ARM64] @@ -4153,13 +4178,11 @@ page_alloc.shuffle= [KNL] Boolean flag to control whether the page allocator - should randomize its free lists. The randomization may - be automatically enabled if the kernel detects it is - running on a platform with a direct-mapped memory-side - cache, and this parameter can be used to - override/disable that behavior. The state of the flag - can be read from sysfs at: + should randomize its free lists. This parameter can be + used to enable/disable page randomization. The state of + the flag can be read from sysfs at: /sys/module/page_alloc/parameters/shuffle. + This parameter is only available if CONFIG_SHUFFLE_PAGE_ALLOCATOR=y. page_owner= [KNL,EARLY] Boot-time page_owner enabling option. Storage of the information about who allocated @@ -4211,6 +4234,7 @@ bit 4: print ftrace buffer bit 5: print all printk messages in buffer bit 6: print all CPUs backtrace (if available in the arch) + bit 7: print only tasks in uninterruptible (blocked) state *Be aware* that this option may print a _lot_ of lines, so there are risks of losing older messages in the log. Use this option carefully, maybe worth to setup a @@ -4573,9 +4597,10 @@ norid [S390] ignore the RID field and force use of one PCI domain per PCI function - pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power + pcie_aspm= [PCIE] Forcibly enable or ignore PCIe Active State Power Management. - off Disable ASPM. + off Don't touch ASPM configuration at all. Leave any + configuration done by firmware unchanged. force Enable ASPM even on devices that claim not to support it. WARNING: Forcing ASPM on may cause system lockups. @@ -4763,7 +4788,9 @@ prot_virt= [S390] enable hosting protected virtual machines isolated from the hypervisor (if hardware supports - that). + that). If enabled, the default kernel base address + might be overridden even when Kernel Address Space + Layout Randomization is disabled. Format: <bool> psi= [KNL] Enable or disable pressure stall information @@ -5074,6 +5101,20 @@ delay, memory pressure or callback list growing too big. + rcutree.rcu_normal_wake_from_gp= [KNL] + Reduces a latency of synchronize_rcu() call. This approach + maintains its own track of synchronize_rcu() callers, so it + does not interact with regular callbacks because it does not + use a call_rcu[_hurry]() path. Please note, this is for a + normal grace period. + + How to enable it: + + echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp + or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1" + + Default is 0. + rcuscale.gp_async= [KNL] Measure performance of asynchronous grace-period primitives such as call_rcu(). @@ -5790,6 +5831,7 @@ but is useful for debugging and performance tuning. sched_thermal_decay_shift= + [Deprecated] [KNL, SMP] Set a decay shift for scheduler thermal pressure signal. Thermal pressure signal follows the default decay period of other scheduler pelt @@ -6046,6 +6088,15 @@ sonypi.*= [HW] Sony Programmable I/O Control Device driver See Documentation/admin-guide/laptops/sonypi.rst + spectre_bhi= [X86] Control mitigation of Branch History Injection + (BHI) vulnerability. This setting affects the + deployment of the HW BHI control and the SW BHB + clearing sequence. + + on - (default) Enable the HW or SW mitigation + as needed. + off - Disable the mitigation. + spectre_v2= [X86,EARLY] Control mitigation of Spectre variant 2 (indirect branch speculation) vulnerability. The default operation protects the kernel from @@ -6582,7 +6633,7 @@ 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. + tp_printk kernel cmdline option has no effect. The tp_printk_stop_on_boot (see below) can also be used to stop the printing of events to console at @@ -6718,6 +6769,7 @@ - "tpm" - "tee" - "caam" + - "dcp" If not specified then it defaults to iterating through the trust source list starting with TPM and assigns the first trust source as a backend which is initialized @@ -6733,6 +6785,18 @@ If not specified, "default" is used. In this case, the RNG's choice is left to each individual trust source. + trusted.dcp_use_otp_key + This is intended to be used in combination with + trusted.source=dcp and will select the DCP OTP key + instead of the DCP UNIQUE key blob encryption. + + trusted.dcp_skip_zk_test + This is intended to be used in combination with + trusted.source=dcp and will disable the check if the + blob key is all zeros. This is helpful for situations where + having this key zero'ed is acceptable. E.g. in testing + scenarios. + tsc= Disable clocksource stability checks for TSC. Format: <string> [x86] reliable: mark tsc clocksource as reliable, this @@ -7293,7 +7357,7 @@ This can be changed after boot by writing to the matching /sys/module/workqueue/parameters file. All workqueues with the "default" affinity scope will be - updated accordignly. + updated accordingly. workqueue.debug_force_rr_cpu Workqueue used to implicitly guarantee that work |