diff options
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 057b13bde82d..a5f651c6df4e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1303,7 +1303,6 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) page = pmd_page(orig_pmd); VM_BUG_ON_PAGE(!PageHead(page), page); - /* Lock page for reuse_swap_page() */ if (!trylock_page(page)) { get_page(page); spin_unlock(vmf->ptl); @@ -1319,10 +1318,15 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) } /* - * We can only reuse the page if nobody else maps the huge page or it's - * part. + * See do_wp_page(): we can only map the page writable if there are + * no additional references. Note that we always drain the LRU + * pagevecs immediately after adding a THP. */ - if (reuse_swap_page(page)) { + if (page_count(page) > 1 + PageSwapCache(page) * thp_nr_pages(page)) + goto unlock_fallback; + if (PageSwapCache(page)) + try_to_free_swap(page); + if (page_count(page) == 1) { pmd_t entry; entry = pmd_mkyoung(orig_pmd); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); @@ -1333,6 +1337,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) return VM_FAULT_WRITE; } +unlock_fallback: unlock_page(page); spin_unlock(vmf->ptl); fallback: |