diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 54 |
1 files changed, 32 insertions, 22 deletions
diff --git a/mm/memory.c b/mm/memory.c index 8dc69471be6c..a62f06750e93 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4125,29 +4125,17 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) goto out; } - /* - * Make it present again, Depending on how arch implementes non - * accessible ptes, some can allow access by kernel mode. - */ - old_pte = ptep_modify_prot_start(vma, vmf->address, vmf->pte); + /* Get the normal PTE */ + old_pte = ptep_get(vmf->pte); pte = pte_modify(old_pte, vma->vm_page_prot); - pte = pte_mkyoung(pte); - if (was_writable) - pte = pte_mkwrite(pte); - ptep_modify_prot_commit(vma, vmf->address, vmf->pte, old_pte, pte); - update_mmu_cache(vma, vmf->address, vmf->pte); page = vm_normal_page(vma, vmf->address, pte); - if (!page) { - pte_unmap_unlock(vmf->pte, vmf->ptl); - return 0; - } + if (!page) + goto out_map; /* TODO: handle PTE-mapped THP */ - if (PageCompound(page)) { - pte_unmap_unlock(vmf->pte, vmf->ptl); - return 0; - } + if (PageCompound(page)) + goto out_map; /* * Avoid grouping on RO pages in general. RO pages shouldn't hurt as @@ -4157,7 +4145,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) * pte_dirty has unpredictable behaviour between PTE scan updates, * background writeback, dirty balancing and application behaviour. */ - if (!pte_write(pte)) + if (!was_writable) flags |= TNF_NO_GROUP; /* @@ -4171,23 +4159,45 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) page_nid = page_to_nid(page); target_nid = numa_migrate_prep(page, vma, vmf->address, page_nid, &flags); - pte_unmap_unlock(vmf->pte, vmf->ptl); if (target_nid == NUMA_NO_NODE) { put_page(page); - goto out; + goto out_map; } + pte_unmap_unlock(vmf->pte, vmf->ptl); /* Migrate to the requested node */ if (migrate_misplaced_page(page, vma, target_nid)) { page_nid = target_nid; flags |= TNF_MIGRATED; - } else + } else { flags |= TNF_MIGRATE_FAIL; + vmf->pte = pte_offset_map(vmf->pmd, vmf->address); + spin_lock(vmf->ptl); + if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) { + pte_unmap_unlock(vmf->pte, vmf->ptl); + goto out; + } + goto out_map; + } out: if (page_nid != NUMA_NO_NODE) task_numa_fault(last_cpupid, page_nid, 1, flags); return 0; +out_map: + /* + * Make it present again, depending on how arch implements + * non-accessible ptes, some can allow access by kernel mode. + */ + old_pte = ptep_modify_prot_start(vma, vmf->address, vmf->pte); + pte = pte_modify(old_pte, vma->vm_page_prot); + pte = pte_mkyoung(pte); + if (was_writable) + pte = pte_mkwrite(pte); + ptep_modify_prot_commit(vma, vmf->address, vmf->pte, old_pte, pte); + update_mmu_cache(vma, vmf->address, vmf->pte); + pte_unmap_unlock(vmf->pte, vmf->ptl); + goto out; } static inline vm_fault_t create_huge_pmd(struct vm_fault *vmf) |