summaryrefslogtreecommitdiff
path: root/Documentation/kernel-parameters.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt55
1 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9776f068306b..28bd0f0e32c5 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1304,6 +1304,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
+ lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline
+ value for LAPIC timer one-shot implementation. Default
+ back to the programmable timer unit in the LAPIC.
+
lapic_timer_c2_ok [X86,APIC] trust the local apic timer
in C2 power state.
@@ -1984,6 +1988,20 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
+ cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
+ CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off.
+ Some features depend on CPU0. Known dependencies are:
+ 1. Resume from suspend/hibernate depends on CPU0.
+ Suspend/hibernate will fail if CPU0 is offline and you
+ need to online CPU0 before suspend/hibernate.
+ 2. PIC interrupts also depend on CPU0. CPU0 can't be
+ removed if a PIC interrupt is detected.
+ It's said poweroff/reboot may depend on CPU0 on some
+ machines although I haven't seen such issues so far
+ after CPU0 is offline on a few tested machines.
+ If the dependencies are under your control, you can
+ turn on cpu0_hotplug.
+
nptcg= [IA-64] Override max number of concurrent global TLB
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
@@ -2394,6 +2412,27 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
See Documentation/blockdev/ramdisk.txt.
+ rcu_nocbs= [KNL,BOOT]
+ In kernels built with CONFIG_RCU_NOCB_CPU=y, set
+ the specified list of CPUs to be no-callback CPUs.
+ Invocation of these CPUs' RCU callbacks will
+ be offloaded to "rcuoN" kthreads created for
+ that purpose. This reduces OS jitter on the
+ offloaded CPUs, which can be useful for HPC and
+ real-time workloads. It can also improve energy
+ efficiency for asymmetric multiprocessors.
+
+ rcu_nocbs_poll [KNL,BOOT]
+ Rather than requiring that offloaded CPUs
+ (specified by rcu_nocbs= above) explicitly
+ awaken the corresponding "rcuoN" kthreads,
+ make these kthreads poll for callbacks.
+ This improves the real-time response for the
+ offloaded CPUs by relieving them of the need to
+ wake up the corresponding kthread, but degrades
+ energy efficiency by requiring that the kthreads
+ periodically wake up to do the polling.
+
rcutree.blimit= [KNL,BOOT]
Set maximum number of finished RCU callbacks to process
in one batch.
@@ -2859,6 +2898,22 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
to facilitate early boot debugging.
See also Documentation/trace/events.txt
+ trace_options=[option-list]
+ [FTRACE] Enable or disable tracer options at boot.
+ The option-list is a comma delimited list of options
+ that can be enabled or disabled just as if you were
+ to echo the option name into
+
+ /sys/kernel/debug/tracing/trace_options
+
+ For example, to enable stacktrace option (to dump the
+ stack trace of each event), add to the command line:
+
+ trace_options=stacktrace
+
+ See also Documentation/trace/ftrace.txt "trace options"
+ section.
+
transparent_hugepage=
[KNL]
Format: [always|madvise|never]