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

From: Gavin Shan
Date: Mon Sep 18 2023 - 21:10:59 EST


On 9/14/23 02:38, James Morse 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.

Remove arch_unregister_cpu() and use the __weak version.

Signed-off-by: James Morse <james.morse@xxxxxxx>
---
arch/loongarch/kernel/topology.c | 9 ---------
1 file changed, 9 deletions(-)

I think arch/x86/kernel/topology.c::arch_unregister_cpu() can be dropped either.

Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>

diff --git a/arch/loongarch/kernel/topology.c b/arch/loongarch/kernel/topology.c
index 8e4441c1ff39..5a75e2cc0848 100644
--- a/arch/loongarch/kernel/topology.c
+++ b/arch/loongarch/kernel/topology.c
@@ -16,13 +16,4 @@ int arch_register_cpu(int cpu)
return register_cpu(c, cpu);
}
EXPORT_SYMBOL(arch_register_cpu);
-
-void arch_unregister_cpu(int cpu)
-{
- struct cpu *c = &per_cpu(cpu_devices, cpu);
-
- c->hotpluggable = 0;
- unregister_cpu(c);
-}
-EXPORT_SYMBOL(arch_unregister_cpu);
#endif

Thanks,
Gavin