From: Hanjun Guo Date: Fri, 21 Jun 2013 09:09:18 +0000 (+0800) Subject: Documentation / CPU hotplug: Rephrase the outdated description for MADT entries X-Git-Tag: firefly_0821_release~176^2~5788^2~13^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=73e797f79e5edb3d000d1911a2d859f15c446c1a;p=firefly-linux-kernel-4.4.55.git Documentation / CPU hotplug: Rephrase the outdated description for MADT entries More than 256 entries in ACPI MADT is supported from ACPI 3.0, so the information in should be Documentation/cpu-hotplug.txt updated. [rjw: Changelog] Suggested-by: Rafael J. Wysocki Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki --- diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt index 9f401350f502..67f733d6f848 100644 --- a/Documentation/cpu-hotplug.txt +++ b/Documentation/cpu-hotplug.txt @@ -370,8 +370,10 @@ A: There is no clear spec defined way from ACPI that can give us that CPUs in MADT as hotpluggable CPUS. In the case there are no disabled CPUS we assume 1/2 the number of CPUs currently present can be hotplugged. - Caveat: Today's ACPI MADT can only provide 256 entries since the apicid field - in MADT is only 8 bits. + Caveat: ACPI MADT can only provide 256 entries in systems with only ACPI 2.0c + or earlier ACPI version supported, because the apicid field in MADT is only + 8 bits. From ACPI 3.0, this limitation was removed since the apicid field + was extended to 32 bits with x2APIC introduced. User Space Notification