diff options
| -rw-r--r-- | mm/rmap.c | 136 |
1 files changed, 74 insertions, 62 deletions
@@ -1426,6 +1426,79 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount, return ret; } +static int try_to_unmap_nonlinear(struct page *page, + struct address_space *mapping, struct vm_area_struct *vma) +{ + int ret = SWAP_AGAIN; + unsigned long cursor; + unsigned long max_nl_cursor = 0; + unsigned long max_nl_size = 0; + unsigned int mapcount; + + list_for_each_entry(vma, + &mapping->i_mmap_nonlinear, shared.nonlinear) { + + cursor = (unsigned long) vma->vm_private_data; + if (cursor > max_nl_cursor) + max_nl_cursor = cursor; + cursor = vma->vm_end - vma->vm_start; + if (cursor > max_nl_size) + max_nl_size = cursor; + } + + if (max_nl_size == 0) { /* all nonlinears locked or reserved ? */ + return SWAP_FAIL; + } + + /* + * We don't try to search for this page in the nonlinear vmas, + * and page_referenced wouldn't have found it anyway. Instead + * just walk the nonlinear vmas trying to age and unmap some. + * The mapcount of the page we came in with is irrelevant, + * but even so use it as a guide to how hard we should try? + */ + mapcount = page_mapcount(page); + if (!mapcount) + return ret; + + cond_resched(); + + max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK; + if (max_nl_cursor == 0) + max_nl_cursor = CLUSTER_SIZE; + + do { + list_for_each_entry(vma, + &mapping->i_mmap_nonlinear, shared.nonlinear) { + + cursor = (unsigned long) vma->vm_private_data; + while (cursor < max_nl_cursor && + cursor < vma->vm_end - vma->vm_start) { + if (try_to_unmap_cluster(cursor, &mapcount, + vma, page) == SWAP_MLOCK) + ret = SWAP_MLOCK; + cursor += CLUSTER_SIZE; + vma->vm_private_data = (void *) cursor; + if ((int)mapcount <= 0) + return ret; + } + vma->vm_private_data = (void *) max_nl_cursor; + } + cond_resched(); + max_nl_cursor += CLUSTER_SIZE; + } while (max_nl_cursor <= max_nl_size); + + /* + * Don't loop forever (perhaps all the remaining pages are + * in locked vmas). Reset cursor on all unreserved nonlinear + * vmas, now forgetting on which ones it had fallen behind. + */ + list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear) + vma->vm_private_data = NULL; + + return ret; +} + bool is_vma_temporary_stack(struct vm_area_struct *vma) { int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP); @@ -1515,10 +1588,6 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) pgoff_t pgoff = page->index << compound_order(page); struct vm_area_struct *vma; int ret = SWAP_AGAIN; - unsigned long cursor; - unsigned long max_nl_cursor = 0; - unsigned long max_nl_size = 0; - unsigned int mapcount; mutex_lock(&mapping->i_mmap_mutex); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { @@ -1539,64 +1608,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) if (TTU_ACTION(flags) == TTU_MUNLOCK) goto out; - list_for_each_entry(vma, &mapping->i_mmap_nonlinear, - shared.nonlinear) { - cursor = (unsigned long) vma->vm_private_data; - if (cursor > max_nl_cursor) - max_nl_cursor = cursor; - cursor = vma->vm_end - vma->vm_start; - if (cursor > max_nl_size) - max_nl_size = cursor; - } - - if (max_nl_size == 0) { /* all nonlinears locked or reserved ? */ - ret = SWAP_FAIL; - goto out; - } - - /* - * We don't try to search for this page in the nonlinear vmas, - * and page_referenced wouldn't have found it anyway. Instead - * just walk the nonlinear vmas trying to age and unmap some. - * The mapcount of the page we came in with is irrelevant, - * but even so use it as a guide to how hard we should try? - */ - mapcount = page_mapcount(page); - if (!mapcount) - goto out; - cond_resched(); - - max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK; - if (max_nl_cursor == 0) - max_nl_cursor = CLUSTER_SIZE; - - do { - list_for_each_entry(vma, &mapping->i_mmap_nonlinear, - shared.nonlinear) { - cursor = (unsigned long) vma->vm_private_data; - while ( cursor < max_nl_cursor && - cursor < vma->vm_end - vma->vm_start) { - if (try_to_unmap_cluster(cursor, &mapcount, - vma, page) == SWAP_MLOCK) - ret = SWAP_MLOCK; - cursor += CLUSTER_SIZE; - vma->vm_private_data = (void *) cursor; - if ((int)mapcount <= 0) - goto out; - } - vma->vm_private_data = (void *) max_nl_cursor; - } - cond_resched(); - max_nl_cursor += CLUSTER_SIZE; - } while (max_nl_cursor <= max_nl_size); - - /* - * Don't loop forever (perhaps all the remaining pages are - * in locked vmas). Reset cursor on all unreserved nonlinear - * vmas, now forgetting on which ones it had fallen behind. - */ - list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear) - vma->vm_private_data = NULL; + ret = try_to_unmap_nonlinear(page, mapping, vma); out: mutex_unlock(&mapping->i_mmap_mutex); return ret; |
