docs: Document possible_cpus parameter

The number of possible CPUs is set be kernel in early boot time through
some discovery mechanisms, like ACPI in x86. We have a parameter both
in x86 and S390 to override that - there are some cases of BIOSes exposing
more possible CPUs than the available ones, so this parameter is a good
testing mechanism, but for some reason wasn't mentioned so far in the
kernel parameters guide - let's fix that.

Cc: Changwoo Min <changwoo@igalia.com>
Signed-off-by: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240203152208.1461293-1-gpiccoli@igalia.com
This commit is contained in:
Guilherme G. Piccoli 2024-02-03 12:21:13 -03:00 committed by Jonathan Corbet
parent 932be49b71
commit 3e3ede49ce

View File

@ -4644,6 +4644,11 @@
may be specified.
Format: <port>,<port>....
possible_cpus= [SMP,S390,X86]
Format: <unsigned int>
Set the number of possible CPUs, overriding the
regular discovery mechanisms (such as ACPI/FW, etc).
powersave=off [PPC] This option disables power saving features.
It specifically disables cpuidle and sets the
platform machine description specific power_save