diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 52 |
1 files changed, 36 insertions, 16 deletions
diff --git a/mm/memory.c b/mm/memory.c index cae514e7dcfc..f75bff2cf662 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2842,7 +2842,7 @@ EXPORT_SYMBOL(unmap_mapping_range); int do_swap_page(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; - struct page *page = NULL, *swapcache; + struct page *page = NULL, *swapcache = NULL; struct mem_cgroup *memcg; struct vma_swap_readahead swap_ra; swp_entry_t entry; @@ -2881,17 +2881,35 @@ int do_swap_page(struct vm_fault *vmf) } goto out; } + + delayacct_set_flag(DELAYACCT_PF_SWAPIN); if (!page) page = lookup_swap_cache(entry, vma_readahead ? vma : NULL, vmf->address); if (!page) { - if (vma_readahead) - page = do_swap_page_readahead(entry, - GFP_HIGHUSER_MOVABLE, vmf, &swap_ra); - else - page = swapin_readahead(entry, - GFP_HIGHUSER_MOVABLE, vma, vmf->address); + struct swap_info_struct *si = swp_swap_info(entry); + + if (!(si->flags & SWP_SYNCHRONOUS_IO)) { + if (vma_readahead) + page = do_swap_page_readahead(entry, + GFP_HIGHUSER_MOVABLE, vmf, &swap_ra); + else + page = swapin_readahead(entry, + GFP_HIGHUSER_MOVABLE, vma, vmf->address); + swapcache = page; + } else { + /* skip swapcache */ + page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address); + if (page) { + __SetPageLocked(page); + __SetPageSwapBacked(page); + set_page_private(page, entry.val); + lru_cache_add_anon(page); + swap_readpage(page, true); + } + } + if (!page) { /* * Back out if somebody else faulted in this pte @@ -2920,7 +2938,6 @@ int do_swap_page(struct vm_fault *vmf) goto out_release; } - swapcache = page; locked = lock_page_or_retry(page, vma->vm_mm, vmf->flags); delayacct_clear_flag(DELAYACCT_PF_SWAPIN); @@ -2935,7 +2952,8 @@ int do_swap_page(struct vm_fault *vmf) * test below, are not enough to exclude that. Even if it is still * swapcache, we need to check that the page's swap has not changed. */ - if (unlikely(!PageSwapCache(page) || page_private(page) != entry.val)) + if (unlikely((!PageSwapCache(page) || + page_private(page) != entry.val)) && swapcache) goto out_page; page = ksm_might_need_to_copy(page, vma, vmf->address); @@ -2988,14 +3006,16 @@ int do_swap_page(struct vm_fault *vmf) pte = pte_mksoft_dirty(pte); set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte); vmf->orig_pte = pte; - if (page == swapcache) { - do_page_add_anon_rmap(page, vma, vmf->address, exclusive); - mem_cgroup_commit_charge(page, memcg, true, false); - activate_page(page); - } else { /* ksm created a completely new copy */ + + /* ksm created a completely new copy */ + if (unlikely(page != swapcache && swapcache)) { page_add_new_anon_rmap(page, vma, vmf->address, false); mem_cgroup_commit_charge(page, memcg, false, false); lru_cache_add_active_or_unevictable(page, vma); + } else { + do_page_add_anon_rmap(page, vma, vmf->address, exclusive); + mem_cgroup_commit_charge(page, memcg, true, false); + activate_page(page); } swap_free(entry); @@ -3003,7 +3023,7 @@ int do_swap_page(struct vm_fault *vmf) (vma->vm_flags & VM_LOCKED) || PageMlocked(page)) try_to_free_swap(page); unlock_page(page); - if (page != swapcache) { + if (page != swapcache && swapcache) { /* * Hold the lock to avoid the swap entry to be reused * until we take the PT lock for the pte_same() check @@ -3036,7 +3056,7 @@ out_page: unlock_page(page); out_release: put_page(page); - if (page != swapcache) { + if (page != swapcache && swapcache) { unlock_page(swapcache); put_page(swapcache); } |