[RFC PATCH v2 25/35] LoongArch: Use the __weak version of arch_unregister_cpu()

Russell King (Oracle) linux at armlinux.org.uk
Mon Oct 23 01:48:09 PDT 2023


On Thu, Sep 14, 2023 at 03:41:11PM +0100, Jonathan Cameron wrote:
> On Wed, 13 Sep 2023 16:38:13 +0000
> James Morse <james.morse at arm.com> wrote:
> 
> > LoongArch provides its own arch_unregister_cpu(). This clears the
> > hotpluggable flag, then unregisters the CPU.
> > 
> > It isn't necessary to clear the hotpluggable flag when unregistering
> > a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices
> > pointer, meaning cpu_is_hotpluggable() will return false, as
> > get_cpu_device() has returned NULL.
> 
> Thought that looked odd earlier but didn't care enough to dig.
> Seem unlikely state would persist for an unregistered cpu.
> Great to see confirmation.

Would it make sense to move this immedaitely after "LoongArch: Switch
over to GENERIC_CPU_DEVICES" ?

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