On Wed, Dec 13, 2023 at 1:49 PM Russell King <rmk+kernel@xxxxxxxxxxxxxxx> wrote: > > From: James Morse <james.morse@xxxxxxx> > > The code behind ACPI_HOTPLUG_CPU allows a not-present CPU to become > present. Right. > This isn't the only use of HOTPLUG_CPU. On arm64 and riscv > CPUs can be taken offline as a power saving measure. But still there is the case in which a non-present CPU can become present, isn't it there? > On arm64 an offline CPU may be disabled by firmware, preventing it from > being brought back online, but it remains present throughout. > > Adding code to prevent user-space trying to online these disabled CPUs > needs some additional terminology. > > Rename the Kconfig symbol CONFIG_ACPI_HOTPLUG_PRESENT_CPU to reflect > that it makes possible CPUs present. Honestly, I don't think that this change is necessary or even useful.
