Re: [PATCH] mm/migrate: fix CPUHP state to update node demotion order

[Thomas Gleixner]

On Sat, Sep 18 2021 at 10:58, Huang Ying wrote:
> @@ -72,6 +72,7 @@ enum cpuhp_state {
>  	CPUHP_SLUB_DEAD,
>  	CPUHP_DEBUG_OBJ_DEAD,
>  	CPUHP_MM_WRITEBACK_DEAD,
> +	CPUHP_MM_DEMOTION_OFFLINE,

Please keep the _DEAD convention in that section. The plugged CPU is
already gone.

>  	CPUHP_MM_VMSTAT_DEAD,
>  	CPUHP_SOFTIRQ_DEAD,
>  	CPUHP_NET_MVNETA_DEAD,
> @@ -240,6 +241,7 @@ enum cpuhp_state {
>  	CPUHP_AP_BASE_CACHEINFO_ONLINE,
>  	CPUHP_AP_ONLINE_DYN,
>  	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,
> +	CPUHP_AP_MM_DEMOTION_ONLINE,

Are there any ordering requirements of these states vs. other CPU
hotplug states?

If not, then please use the dynamically allocated states.

If so, then please add a comment:

+	/* Must be before CPUHP_XXX and after CPUHP_YYY */
+	CPUHP_MM_DEMOTION_OFFLINE,

Thanks,

        tglx