diff options
Diffstat (limited to 'Documentation/power/suspend-and-cpuhotplug.txt')
| -rw-r--r-- | Documentation/power/suspend-and-cpuhotplug.txt | 9 |
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 |