On Thu, Apr 08, 2021 at 11:52:51AM +0200, Oscar Salvador wrote: > I am not really into PMEM, and I ignore whether we need > CONFIG_MEMORY_HOTPLUG in order to have such memory on the system. > If so, the following can be partly ignored. Ok, I refreshed by memory with [1]. >From that, it seems that in order to use PMEM as RAM we need CONFIG_MEMORY_HOTPLUG. But is that always the case? Can happen that in some scenario PMEM comes ready to use and we do not need the hotplug trick? Anyway, I would still like to clarify the state of the HOTPLUG_CPU. On x86_64, HOTPLUG_CPU and MEMORY_HOTPLUG are tied by SPM means, but on arm64 one can have MEMORY_HOTPLUG while not having picked HOTPLUG_CPU. My point is that we might want to put the callback functions and the callback registration for cpu-hotplug guarded by its own HOTPLUG_CPU instead of guarding it in the same MEMORY_HOTPLUG block to make it more clear? -- Oscar Salvador SUSE L3
