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authorThomas Gleixner <tglx@linutronix.de>2017-11-13 11:39:01 +0300
committerThomas Gleixner <tglx@linutronix.de>2017-11-13 12:03:53 +0300
commitf4c09f87adfe31587aa4b2aea2cb2dbde2150f54 (patch)
tree2f447482a8c304bc26d0ae02172f979e6ecd5c5b /Documentation/power/suspend-and-cpuhotplug.txt
parentc6cd924efe941ef62eb805c59e4a09e219ac5c6d (diff)
downloadlinux-f4c09f87adfe31587aa4b2aea2cb2dbde2150f54.tar.xz
cpu/hotplug: Get rid of CPU hotplug notifier leftovers
The CPU hotplug notifiers are history. Remove the last reminders. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation/power/suspend-and-cpuhotplug.txt')
-rw-r--r--Documentation/power/suspend-and-cpuhotplug.txt9
1 files changed, 4 insertions, 5 deletions
diff --git a/Documentation/power/suspend-and-cpuhotplug.txt b/Documentation/power/suspend-and-cpuhotplug.txt
index 2fc909502db5..31abd04b9572 100644
--- a/Documentation/power/suspend-and-cpuhotplug.txt
+++ b/Documentation/power/suspend-and-cpuhotplug.txt
@@ -232,7 +232,7 @@ d. Handling microcode update during suspend/hibernate:
hibernate/restore cycle.]
In the current design of the kernel however, during a CPU offline operation
- as part of the suspend/hibernate cycle (the CPU_DEAD_FROZEN notification),
+ as part of the suspend/hibernate cycle (cpuhp_tasks_frozen is set),
the existing copy of microcode image in the kernel is not freed up.
And during the CPU online operations (during resume/restore), since the
kernel finds that it already has copies of the microcode images for all the
@@ -252,10 +252,9 @@ Yes, they are listed below:
the _cpu_down() and _cpu_up() functions is *always* 0.
This might not reflect the true current state of the system, since the
tasks could have been frozen by an out-of-band event such as a suspend
- operation in progress. Hence, it will lead to wrong notifications being
- sent during the cpu online/offline events (eg, CPU_ONLINE notification
- instead of CPU_ONLINE_FROZEN) which in turn will lead to execution of
- inappropriate code by the callbacks registered for such CPU hotplug events.
+ operation in progress. Hence, the cpuhp_tasks_frozen variable will not
+ reflect the frozen state and the CPU hotplug callbacks which evaluate
+ that variable might execute the wrong code path.
2. If a regular CPU hotplug stress test happens to race with the freezer due
to a suspend operation in progress at the same time, then we could hit the