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