On Thu, Nov 09, 2023 at 11:25:20AM +0800, Jeff Xie wrote: > +static int filemap_alloc_post_page_owner(struct folio *folio, struct task_struct *tsk, > + void *data, char *kbuf, size_t count) > +{ > + int ret; > + int mapcount; > + dev_t s_dev; > + struct inode *inode; > + struct vm_area_struct *vma; > + struct mm_struct *mm; > + unsigned long virtual_start = 0x0; > + unsigned long virtual_end = 0x0; > + struct address_space *mapping = data; This is just folio->mapping. > + mapcount = folio_mapcount(folio); > + if (mapcount && tsk && tsk->mm) { > + mm = tsk->mm; > + VMA_ITERATOR(vmi, mm, 0); > + mmap_read_lock(mm); > + for_each_vma(vmi, vma) { > + if (page_mapped_in_vma(&folio->page, vma)) { > + virtual_start = vma_address(&folio->page, vma); > + virtual_end = virtual_start + folio_nr_pages(folio) * PAGE_SIZE; > + break; > + } > + } > + mmap_read_unlock(mm); > + } Why not just walk the rmap directly to find out where it's mapped in any process instead of the one which allocated it?