diff --git a/mm/memory.c b/mm/memory.c index 27e225bef5d0..9c886e4207a2 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3125,9 +3125,20 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address); if (page) { + int err; + __SetPageLocked(page); __SetPageSwapBacked(page); set_page_private(page, entry.val); + + /* Tell memcg to use swap ownership records */ + SetPageSwapCache(page); + err = mem_cgroup_charge(page, vma->vm_mm, + GFP_KERNEL, false); + ClearPageSwapCache(page); + if (err) + goto out_page; + lru_cache_add_anon(page); swap_readpage(page, true); } @@ -3189,10 +3200,6 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) goto out_page; } - if (mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL, true)) { - ret = VM_FAULT_OOM; - goto out_page; - } cgroup_throttle_swaprate(page, GFP_KERNEL); /* diff --git a/mm/shmem.c b/mm/shmem.c index 71842fd4a9d0..b79116185046 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -623,13 +623,15 @@ static int shmem_add_to_page_cache(struct page *page, page->mapping = mapping; page->index = index; - error = mem_cgroup_charge(page, charge_mm, gfp, PageSwapCache(page)); - if (error) { - if (!PageSwapCache(page) && PageTransHuge(page)) { - count_vm_event(THP_FILE_FALLBACK); - count_vm_event(THP_FILE_FALLBACK_CHARGE); + if (!PageSwapCache(page)) { + error = mem_cgroup_charge(page, charge_mm, gfp, false); + if (error) { + if (PageTransHuge(page)) { + count_vm_event(THP_FILE_FALLBACK); + count_vm_event(THP_FILE_FALLBACK_CHARGE); + } + goto error; } - goto error; } cgroup_throttle_swaprate(page, gfp); diff --git a/mm/swap_state.c b/mm/swap_state.c index 8238954ae781..f841257a3014 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -360,12 +360,13 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, struct vm_area_struct *vma, unsigned long addr, bool *new_page_allocated) { - struct page *found_page = NULL, *new_page = NULL; struct swap_info_struct *si; - int err; + struct page *page; + *new_page_allocated = false; - do { + for (;;) { + int err; /* * First check the swap cache. Since this is normally * called after lookup_swap_cache() failed, re-calling @@ -373,12 +374,12 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, */ si = get_swap_device(entry); if (!si) - break; - found_page = find_get_page(swap_address_space(entry), - swp_offset(entry)); + return NULL; + page = find_get_page(swap_address_space(entry), + swp_offset(entry)); put_swap_device(si); - if (found_page) - break; + if (page) + return page; /* * Just skip read ahead for unused swap slot. @@ -389,54 +390,66 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, * else swap_off will be aborted if we return NULL. */ if (!__swp_swapcount(entry) && swap_slot_cache_enabled) - break; + return NULL; /* - * Get a new page to read into from swap. + * Get a new page to read into from swap. Allocate it now, + * before marking swap_map SWAP_HAS_CACHE, when -EEXIST will + * cause any racers to loop around until we add it to cache. */ - if (!new_page) { - new_page = alloc_page_vma(gfp_mask, vma, addr); - if (!new_page) - break; /* Out of memory */ - } + page = alloc_page_vma(gfp_mask, vma, addr); + if (!page) + return NULL; /* * Swap entry may have been freed since our caller observed it. */ err = swapcache_prepare(entry); - if (err == -EEXIST) { - /* - * We might race against get_swap_page() and stumble - * across a SWAP_HAS_CACHE swap_map entry whose page - * has not been brought into the swapcache yet. - */ - cond_resched(); - continue; - } else if (err) /* swp entry is obsolete ? */ + if (!err) break; - /* May fail (-ENOMEM) if XArray node allocation failed. */ - __SetPageLocked(new_page); - __SetPageSwapBacked(new_page); - err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL); - if (likely(!err)) { - /* Initiate read into locked page */ - SetPageWorkingset(new_page); - lru_cache_add_anon(new_page); - *new_page_allocated = true; - return new_page; - } - __ClearPageLocked(new_page); - /* - * add_to_swap_cache() doesn't return -EEXIST, so we can safely - * clear SWAP_HAS_CACHE flag. - */ - put_swap_page(new_page, entry); - } while (err != -ENOMEM); + put_page(page); + if (err != -EEXIST) + return NULL; - if (new_page) - put_page(new_page); - return found_page; + /* + * We might race against __delete_from_swap_cache(), and + * stumble across a swap_map entry whose SWAP_HAS_CACHE + * has not yet been cleared. Or race against another + * __read_swap_cache_async(), which has set SWAP_HAS_CACHE + * in swap_map, but not yet added its page to swap cache. + */ + cond_resched(); + } + + /* + * The swap entry is ours to swap in. Prepare the new page. + */ + + __SetPageLocked(page); + __SetPageSwapBacked(page); + + /* May fail (-ENOMEM) if XArray node allocation failed. */ + if (add_to_swap_cache(page, entry, gfp_mask & GFP_KERNEL)) { + put_swap_page(page, entry); + goto fail_unlock; + } + + if (mem_cgroup_charge(page, NULL, gfp_mask, false)) { + delete_from_swap_cache(page); + goto fail_unlock; + } + + /* Caller will initiate read into locked page */ + SetPageWorkingset(page); + lru_cache_add_anon(page); + *new_page_allocated = true; + return page; + +fail_unlock: + unlock_page(page); + put_page(page); + return NULL; } /* diff --git a/mm/swapfile.c b/mm/swapfile.c index 720e9a924c01..a3d191e205f2 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1901,11 +1901,6 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, if (unlikely(!page)) return -ENOMEM; - if (mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL, true)) { - ret = -ENOMEM; - goto out_nolock; - } - pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); if (unlikely(!pte_same_as_swp(*pte, swp_entry_to_pte(entry)))) { ret = 0; @@ -1931,7 +1926,6 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, activate_page(page); out: pte_unmap_unlock(pte, ptl); -out_nolock: if (page != swapcache) { unlock_page(page); put_page(page);