Machine check
mce=off disable machine check
+ mce=bootlog Enable logging of machine checks left over from booting.
+ Disabled by default on AMD because some BIOS leave bogus ones.
+ If your BIOS doesn't do that it's a good idea to enable though
+ to make sure you log even machine check events that result
+ in a reboot. On Intel systems it is enabled by default.
+ mce=nobootlog
+ Disable boot machine check logging.
+ mce=tolerancelevel (number)
+ 0: always panic, 1: panic if deadlock possible,
+ 2: try to avoid panic, 3: never panic or exit (for testing)
+ default is 1
+ Can be also set using sysfs which is preferable.
nomce (for compatibility with i386): same as mce=off
notsc
Don't use the CPU time stamp counter to read the wall time.
This can be used to work around timing problems on multiprocessor systems
- with not properly synchronized CPUs. Only useful with a SMP kernel
+ with not properly synchronized CPUs.
report_lost_ticks
Report when timer interrupts are lost because some code turned off
event. This will make the CPUs eat a lot more power, but may be useful
to get slightly better performance in multiprocessor benchmarks. It also
makes some profiling using performance counters more accurate.
+ Please note that on systems with MONITOR/MWAIT support (like Intel EM64T
+ CPUs) this option has no performance advantage over the normal idle loop.
+ It may also interact badly with hyperthreading.
Rebooting
cpumask=MASK only use cpus with bits set in mask
+ additional_cpus=NUM Allow NUM more CPUs for hotplug
+ (defaults are specified by the BIOS or half the available CPUs)
+
NUMA
numa=off Only set up a single NUMA node spanning all memory.
kstack=N Print that many words from the kernel stack in oops dumps.
+ pagefaulttrace Dump all page faults. Only useful for extreme debugging
+ and will create a lot of output.
+
Misc
noreplacement Don't replace instructions with more appropiate ones
- for the CPU. This may be useful on asymmetric MP systems
- where some CPU have less capabilities than the others.
-
+ for the CPU. This may be useful on asymmetric MP systems
+ where some CPU have less capabilities than the others.