diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/mm/memory.c b/mm/memory.c index 159985d..6204ce2 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -208,10 +208,14 @@ static int tlb_next_batch(struct mmu_gather *tlb) return 1; } + if (tlb->batch_count == MAX_GATHER_BATCH_COUNT) + return 0; + batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); if (!batch) return 0; + tlb->batch_count++; batch->next = NULL; batch->nr = 0; batch->max = MAX_GATHER_BATCH; @@ -238,6 +242,7 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) tlb->local.nr = 0; tlb->local.max = ARRAY_SIZE(tlb->__pages); tlb->active = &tlb->local; + tlb->batch_count = 0; #ifdef CONFIG_HAVE_RCU_TABLE_FREE tlb->batch = NULL; @@ -3568,6 +3573,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (unlikely(is_vm_hugetlb_page(vma))) return hugetlb_fault(mm, vma, address, flags); +retry: pgd = pgd_offset(mm, address); pud = pud_alloc(mm, pgd, address); if (!pud) @@ -3581,13 +3587,24 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, pmd, flags); } else { pmd_t orig_pmd = *pmd; + int ret; + barrier(); if (pmd_trans_huge(orig_pmd)) { if (flags & FAULT_FLAG_WRITE && !pmd_write(orig_pmd) && - !pmd_trans_splitting(orig_pmd)) - return do_huge_pmd_wp_page(mm, vma, address, - pmd, orig_pmd); + !pmd_trans_splitting(orig_pmd)) { + ret = do_huge_pmd_wp_page(mm, vma, address, pmd, + orig_pmd); + /* + * If COW results in an oom, the huge pmd will + * have been split, so retry the fault on the + * pte for a smaller charge. + */ + if (unlikely(ret & VM_FAULT_OOM)) + goto retry; + return ret; + } return 0; } } |