Documentation / CPU hotplug: Rephrase the outdated description for MADT entries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 <rjw@sisk.pl>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Hanjun Guo 2013-06-21 17:09:18 +08:00 committed by Rafael J. Wysocki
parent 86393865f0
commit 73e797f79e
1 changed files with 4 additions and 2 deletions

View File

@ -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.
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