diff options
| -rw-r--r-- | fs/proc/task_mmu.c | 42 | ||||
| -rw-r--r-- | include/linux/shmem_fs.h | 2 | ||||
| -rw-r--r-- | mm/shmem.c | 65 |
3 files changed, 53 insertions, 56 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 5830b2e129ed..8a03759bda38 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -488,42 +488,16 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page, } #ifdef CONFIG_SHMEM -static unsigned long smaps_shmem_swap(struct vm_area_struct *vma, - unsigned long addr) -{ - struct page *page; - - page = find_get_entry(vma->vm_file->f_mapping, - linear_page_index(vma, addr)); - if (!page) - return 0; - - if (radix_tree_exceptional_entry(page)) - return PAGE_SIZE; - - page_cache_release(page); - return 0; - -} - static int smaps_pte_hole(unsigned long addr, unsigned long end, struct mm_walk *walk) { struct mem_size_stats *mss = walk->private; - while (addr < end) { - mss->swap += smaps_shmem_swap(walk->vma, addr); - addr += PAGE_SIZE; - } + mss->swap += shmem_partial_swap_usage( + walk->vma->vm_file->f_mapping, addr, end); return 0; } -#else -static unsigned long smaps_shmem_swap(struct vm_area_struct *vma, - unsigned long addr) -{ - return 0; -} #endif static void smaps_pte_entry(pte_t *pte, unsigned long addr, @@ -555,7 +529,17 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr, page = migration_entry_to_page(swpent); } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap && pte_none(*pte))) { - mss->swap += smaps_shmem_swap(vma, addr); + page = find_get_entry(vma->vm_file->f_mapping, + linear_page_index(vma, addr)); + if (!page) + return; + + if (radix_tree_exceptional_entry(page)) + mss->swap += PAGE_SIZE; + else + page_cache_release(page); + + return; } if (!page) diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index bd58be5e7a2a..a43f41cb3c43 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -61,6 +61,8 @@ extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); extern int shmem_unuse(swp_entry_t entry, struct page *page); extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); +extern unsigned long shmem_partial_swap_usage(struct address_space *mapping, + pgoff_t start, pgoff_t end); static inline struct page *shmem_read_mapping_page( struct address_space *mapping, pgoff_t index) diff --git a/mm/shmem.c b/mm/shmem.c index e978621de1ef..760d90cf2a41 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -361,41 +361,18 @@ static int shmem_free_swap(struct address_space *mapping, /* * Determine (in bytes) how many of the shmem object's pages mapped by the - * given vma is swapped out. + * given offsets are swapped out. * * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU, * as long as the inode doesn't go away and racy results are not a problem. */ -unsigned long shmem_swap_usage(struct vm_area_struct *vma) +unsigned long shmem_partial_swap_usage(struct address_space *mapping, + pgoff_t start, pgoff_t end) { - struct inode *inode = file_inode(vma->vm_file); - struct shmem_inode_info *info = SHMEM_I(inode); - struct address_space *mapping = inode->i_mapping; - unsigned long swapped; - pgoff_t start, end; struct radix_tree_iter iter; void **slot; struct page *page; - - /* Be careful as we don't hold info->lock */ - swapped = READ_ONCE(info->swapped); - - /* - * The easier cases are when the shmem object has nothing in swap, or - * the vma maps it whole. Then we can simply use the stats that we - * already track. - */ - if (!swapped) - return 0; - - if (!vma->vm_pgoff && vma->vm_end - vma->vm_start >= inode->i_size) - return swapped << PAGE_SHIFT; - - swapped = 0; - - /* Here comes the more involved part */ - start = linear_page_index(vma, vma->vm_start); - end = linear_page_index(vma, vma->vm_end); + unsigned long swapped = 0; rcu_read_lock(); @@ -430,6 +407,40 @@ restart: } /* + * Determine (in bytes) how many of the shmem object's pages mapped by the + * given vma is swapped out. + * + * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU, + * as long as the inode doesn't go away and racy results are not a problem. + */ +unsigned long shmem_swap_usage(struct vm_area_struct *vma) +{ + struct inode *inode = file_inode(vma->vm_file); + struct shmem_inode_info *info = SHMEM_I(inode); + struct address_space *mapping = inode->i_mapping; + unsigned long swapped; + + /* Be careful as we don't hold info->lock */ + swapped = READ_ONCE(info->swapped); + + /* + * The easier cases are when the shmem object has nothing in swap, or + * the vma maps it whole. Then we can simply use the stats that we + * already track. + */ + if (!swapped) + return 0; + + if (!vma->vm_pgoff && vma->vm_end - vma->vm_start >= inode->i_size) + return swapped << PAGE_SHIFT; + + /* Here comes the more involved part */ + return shmem_partial_swap_usage(mapping, + linear_page_index(vma, vma->vm_start), + linear_page_index(vma, vma->vm_end)); +} + +/* * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists. */ void shmem_unlock_mapping(struct address_space *mapping) |