On Fri 19-07-24 19:58:39, Qu Wenruo wrote: > There is an incoming btrfs patchset, which will use @root_mem_cgroup as > the active cgroup to attach metadata folios to its internal btree > inode, so that btrfs can skip the possibly costly charge for the > internal inode which is only accessible by btrfs itself. > > However @root_mem_cgroup is not always defined (not defined for > CONFIG_MEMCG=n case), thus all such callers need to do the extra > handling for different CONFIG_MEMCG settings. > > So here we add a special macro definition of root_mem_cgroup, making it > to always be NULL. Isn't just a declaration sufficient? Nothing should really dereference the pointer anyway. -- Michal Hocko SUSE Labs
