diff options
Diffstat (limited to 'mm/swap_state.c')
| -rw-r--r-- | mm/swap_state.c | 52 |
1 files changed, 18 insertions, 34 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c index 71ce2d1ccbf7..05b6803f0cce 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -39,10 +39,6 @@ struct address_space *swapper_spaces[MAX_SWAPFILES]; static unsigned int nr_swapper_spaces[MAX_SWAPFILES]; bool swap_vma_readahead = true; -#define SWAP_RA_MAX_ORDER_DEFAULT 3 - -static int swap_ra_max_order = SWAP_RA_MAX_ORDER_DEFAULT; - #define SWAP_RA_WIN_SHIFT (PAGE_SHIFT / 2) #define SWAP_RA_HITS_MASK ((1UL << SWAP_RA_WIN_SHIFT) - 1) #define SWAP_RA_HITS_MAX SWAP_RA_HITS_MASK @@ -242,6 +238,17 @@ int add_to_swap(struct page *page) * clear SWAP_HAS_CACHE flag. */ goto fail; + /* + * Normally the page will be dirtied in unmap because its pte should be + * dirty. A special case is MADV_FREE page. The page'e pte could have + * dirty bit cleared but the page's SwapBacked bit is still set because + * clearing the dirty bit and SwapBacked bit has no lock protected. For + * such page, unmap will not set dirty bit for it, so page reclaim will + * not write the page out. This can cause data corruption when the page + * is swap in later. Always setting the dirty bit for the page solves + * the problem. + */ + set_page_dirty(page); return 1; @@ -653,6 +660,13 @@ struct page *swap_readahead_detect(struct vm_fault *vmf, pte_t *tpte; #endif + max_win = 1 << min_t(unsigned int, READ_ONCE(page_cluster), + SWAP_RA_ORDER_CEILING); + if (max_win == 1) { + swap_ra->win = 1; + return NULL; + } + faddr = vmf->address; entry = pte_to_swp_entry(vmf->orig_pte); if ((unlikely(non_swap_entry(entry)))) @@ -661,12 +675,6 @@ struct page *swap_readahead_detect(struct vm_fault *vmf, if (page) return page; - max_win = 1 << READ_ONCE(swap_ra_max_order); - if (max_win == 1) { - swap_ra->win = 1; - return NULL; - } - fpfn = PFN_DOWN(faddr); swap_ra_info = GET_SWAP_RA_VAL(vma); pfn = PFN_DOWN(SWAP_RA_ADDR(swap_ra_info)); @@ -775,32 +783,8 @@ static struct kobj_attribute vma_ra_enabled_attr = __ATTR(vma_ra_enabled, 0644, vma_ra_enabled_show, vma_ra_enabled_store); -static ssize_t vma_ra_max_order_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) -{ - return sprintf(buf, "%d\n", swap_ra_max_order); -} -static ssize_t vma_ra_max_order_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) -{ - int err, v; - - err = kstrtoint(buf, 10, &v); - if (err || v > SWAP_RA_ORDER_CEILING || v <= 0) - return -EINVAL; - - swap_ra_max_order = v; - - return count; -} -static struct kobj_attribute vma_ra_max_order_attr = - __ATTR(vma_ra_max_order, 0644, vma_ra_max_order_show, - vma_ra_max_order_store); - static struct attribute *swap_attrs[] = { &vma_ra_enabled_attr.attr, - &vma_ra_max_order_attr.attr, NULL, }; |