X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=Documentation%2Fcpu-hotplug.txt;h=a741f658a3c9d7393c9693bb4486d30473438222;hb=bb0851ff9dc65dd9c9365fdb87895d98235ac463;hp=4868c34f75090fe75b4f6bb28f70c7638540c4cd;hpb=7c2aed4b5632fb536721b8494d1a4a65852ffb49;p=powerpc.git

diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
index 4868c34f75..a741f658a3 100644
--- a/Documentation/cpu-hotplug.txt
+++ b/Documentation/cpu-hotplug.txt
@@ -54,8 +54,8 @@ additional_cpus=n (*)	Use this to limit hotpluggable cpus. This option sets
 
 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 doesnt
+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.
 
@@ -217,14 +217,19 @@ Q: What happens when a CPU is being logically offlined?
 A: The following happen, listed in no particular order :-)
 
 - A notification is sent to in-kernel registered modules by sending an event
-  CPU_DOWN_PREPARE
-- All process is migrated away from this outgoing CPU to a new CPU
+  CPU_DOWN_PREPARE or CPU_DOWN_PREPARE_FROZEN, depending on whether or not the
+  CPU is being offlined while tasks are frozen due to a suspend operation in
+  progress
+- All processes are migrated away from this outgoing CPU to new CPUs.
+  The new CPU is chosen from each process' current cpuset, which may be
+  a subset of all online CPUs.
 - All interrupts targeted to this CPU is migrated to a new CPU
 - timers/bottom half/task lets are also migrated to a new CPU
 - Once all services are migrated, kernel calls an arch specific routine
   __cpu_disable() to perform arch specific cleanup.
 - Once this is successful, an event for successful cleanup is sent by an event
-  CPU_DEAD.
+  CPU_DEAD (or CPU_DEAD_FROZEN if tasks are frozen due to a suspend while the
+  CPU is being offlined).
 
   "It is expected that each service cleans up when the CPU_DOWN_PREPARE
   notifier is called, when CPU_DEAD is called its expected there is nothing
@@ -242,9 +247,11 @@ A: This is what you would need in your kernel code to receive notifications.
 
 		switch (action) {
 		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
 			foobar_online_action(cpu);
 			break;
 		case CPU_DEAD:
+		case CPU_DEAD_FROZEN:
 			foobar_dead_action(cpu);
 			break;
 		}