X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=Documentation%2Fcpu-hotplug.txt;h=9d620c153b04f2469bf664e6489e3af6817663e2;hb=04bedd79a7037ee7af816b06c60c738144475c4a;hp=94bbc27ddd4fbf50ff361177450c5f524210f1cb;hpb=429b022af41108f6942d72547592b1d30e9a51f0;p=~andy%2Flinux diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt index 94bbc27ddd4..9d620c153b0 100644 --- a/Documentation/cpu-hotplug.txt +++ b/Documentation/cpu-hotplug.txt @@ -50,16 +50,17 @@ additional_cpus=n (*) Use this to limit hotpluggable cpus. This option sets cpu_possible_map = cpu_present_map + additional_cpus (*) Option valid only for following architectures -- x86_64, ia64 +- ia64 -ia64 and x86_64 use the number of disabled local apics in ACPI tables MADT -to determine the number of potentially hot-pluggable cpus. The implementation -should only rely on this to count the # of cpus, but *MUST* not rely on the -apicid values in those tables for disabled apics. In the event BIOS doesn't -mark such hot-pluggable cpus as disabled entries, one could use this -parameter "additional_cpus=x" to represent those cpus in the cpu_possible_map. +ia64 uses the number of disabled local apics in ACPI tables MADT to +determine the number of potentially hot-pluggable cpus. The implementation +should only rely on this to count the # of cpus, but *MUST* not rely +on the apicid values in those tables for disabled apics. In the event +BIOS doesn't mark such hot-pluggable cpus as disabled entries, one could +use this parameter "additional_cpus=x" to represent those cpus in the +cpu_possible_map. -possible_cpus=n [s390 only] use this to set hotpluggable cpus. +possible_cpus=n [s390,x86_64] use this to set hotpluggable cpus. This option sets possible_cpus bits in cpu_possible_map. Thus keeping the numbers of bits set constant even if the machine gets rebooted.