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@xxxxxxxxxx> Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> --- Documentation/admin-guide/kernel-parameters.txt | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 31b3a25680d0..e553740190ea 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -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 -- 2.43.0