On Mon 13-09-21 19:34:23, Feng Tang wrote: > On Mon, Sep 13, 2021 at 11:15:54AM +0200, Michal Hocko wrote: [...] > > > +/* Whether the 'nodes' are all movable nodes */ > > > +static inline bool movable_only_nodes(nodemask_t *nodes) > > > +{ > > > + struct zonelist *zonelist; > > > + struct zoneref *z; > > > + > > > + zonelist = &(first_online_pgdat())->node_zonelists[ZONELIST_FALLBACK]; > > > > This will work but it just begs a question why you haven't chosen a node > > from the given nodemask. So I believe it would be easier to read if you > > did > > zonelist = NODE_DATA(first_node(nodes))->node_zonelists[ZONELIST_FALLBACK] > > This was also my first try to get the 'zonelist', but from the > update_nodemask(), the nodemask could be NULL. I guess you meant to say s@NULL@empty@ While this complicates things a bit it is nothing really hard to work around. You simply check for nodes_empty() and return false because such a nodemask cannot by definition be movable only. -- Michal Hocko SUSE Labs