If the dependencies are under your control, you can
turn on cpu0_hotplug.
+ cpufreq_driver= [X86] Allow only the named cpu frequency scaling driver
+ to register. Example: cpufreq_driver=powernow-k8
+ Format: { none | STRING }
+
cpuidle.off=1 [CPU_IDLE]
disable the cpuidle sub-system
no_entry_flush [PPC]
no_uaccess_flush [PPC]
mmio_stale_data=off [X86]
+ retbleed=off [X86]
Exceptions:
This does not have any effect on
mds=full,nosmt [X86]
tsx_async_abort=full,nosmt [X86]
mmio_stale_data=full,nosmt [X86]
+ retbleed=auto,nosmt [X86]
mminit_loglevel=
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
nomsi [MSI] If the PCI_MSI kernel config parameter is
enabled, this kernel boot option can be used to
disable the use of MSI interrupts system-wide.
+ clearmsi [X86] Clears MSI/MSI-X enable bits early in boot
+ time in order to avoid issues like adapters
+ screaming irqs and preventing boot progress.
+ Also, it enforces the PCI Local Bus spec
+ rule that those bits should be 0 in system reset
+ events (useful for kexec/kdump cases).
noioapicquirk [APIC] Disable all boot interrupt quirks.
Safety option to keep boot IRQs enabled. This
should never be necessary.
Speculative Code Execution with Return Instructions)
vulnerability.
+ AMD-based UNRET and IBPB mitigations alone do not stop
+ sibling threads from influencing the predictions of other
+ sibling threads. For that reason, STIBP is used on pro-
+ cessors that support it, and mitigate SMT on processors
+ that don't.
+
off - no mitigation
auto - automatically select a migitation
auto,nosmt - automatically select a mitigation,
disabling SMT if necessary for
the full mitigation (only on Zen1
and older without STIBP).
- ibpb - mitigate short speculation windows on
- basic block boundaries too. Safe, highest
- perf impact.
- unret - force enable untrained return thunks,
- only effective on AMD f15h-f17h
- based systems.
- unret,nosmt - like unret, will disable SMT when STIBP
- is not available.
+ ibpb - On AMD, mitigate short speculation
+ windows on basic block boundaries too.
+ Safe, highest perf impact. It also
+ enables STIBP if present. Not suitable
+ on Intel.
+ ibpb,nosmt - Like "ibpb" above but will disable SMT
+ when STIBP is not available. This is
+ the alternative for systems which do not
+ have STIBP.
+ unret - Force enable untrained return thunks,
+ only effective on AMD f15h-f17h based
+ systems.
+ unret,nosmt - Like unret, but will disable SMT when STIBP
+ is not available. This is the alternative for
+ systems which do not have STIBP.
Selecting 'auto' will choose a mitigation method at run
time according to the CPU.
rodata= [KNL]
on Mark read-only kernel memory as read-only (default).
off Leave read-only kernel memory writable for debugging.
+ full Mark read-only kernel memory and aliases as read-only
+ [arm64]
rockchip.usb_uart
Enable the uart passthrough on the designated usb port
expediting. Set to zero to disable automatic
expediting.
+ srcutree.srcu_max_nodelay [KNL]
+ Specifies the number of no-delay instances
+ per jiffy for which the SRCU grace period
+ worker thread will be rescheduled with zero
+ delay. Beyond this limit, worker thread will
+ be rescheduled with a sleep delay of one jiffy.
+
+ srcutree.srcu_max_nodelay_phase [KNL]
+ Specifies the per-grace-period phase, number of
+ non-sleeping polls of readers. Beyond this limit,
+ grace period worker thread will be rescheduled
+ with a sleep delay of one jiffy, between each
+ rescan of the readers, for a grace period phase.
+
+ srcutree.srcu_retry_check_delay [KNL]
+ Specifies number of microseconds of non-sleeping
+ delay between each non-sleeping poll of readers.
+
srcutree.small_contention_lim [KNL]
Specifies the number of update-side contention
events per jiffy will be tolerated before
projects / mirror_ubuntu-kinetic-kernel.git / blobdiff