On Wed, Oct 10, 2018 at 03:19:09PM +0800, Huang Ying wrote: > +#ifdef CONFIG_THP_SWAP > +/* > + * The corresponding page table shouldn't be changed under us, that > + * is, the page table lock should be held. > + */ > +int split_swap_cluster_map(swp_entry_t entry) > +{ > + struct swap_info_struct *si; > + struct swap_cluster_info *ci; > + unsigned long offset = swp_offset(entry); > + > + VM_BUG_ON(!IS_ALIGNED(offset, SWAPFILE_CLUSTER)); > + si = _swap_info_get(entry); > + if (!si) > + return -EBUSY; I think this return value doesn't get used anywhere?