rk3168:support act8846 set sleep voltage

[firefly-linux-kernel-4.4.55.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 05f8fd425f69e3a8de95e13e75444c20a66aa46a..037f077b986525796df3263ea118a24a7e4f7e4f 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -460,8 +460,10 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
        struct zonelist *zonelist;
        struct zone *zone;
        struct zoneref *z;
+       unsigned int cpuset_mems_cookie;
 
-       get_mems_allowed();
+retry_cpuset:
+       cpuset_mems_cookie = get_mems_allowed();
        zonelist = huge_zonelist(vma, address,
                                        htlb_alloc_mask, &mpol, &nodemask);
        /*
@@ -488,10 +490,15 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
                        }
                }
        }
-err:
+
        mpol_cond_put(mpol);
-       put_mems_allowed();
+       if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+               goto retry_cpuset;
        return page;
+
+err:
+       mpol_cond_put(mpol);
+       return NULL;
 }
 
 static void update_and_free_page(struct hstate *h, struct page *page)
@@ -2294,6 +2301,22 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 {
        mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
        __unmap_hugepage_range(vma, start, end, ref_page);
+       /*
+        * Clear this flag so that x86's huge_pmd_share page_table_shareable
+        * test will fail on a vma being torn down, and not grab a page table
+        * on its way out.  We're lucky that the flag has such an appropriate
+        * name, and can in fact be safely cleared here. We could clear it
+        * before the __unmap_hugepage_range above, but all that's necessary
+        * is to clear it before releasing the i_mmap_mutex below.
+        *
+        * This works because in the contexts this is called, the VMA is
+        * going to be destroyed. It is not vunerable to madvise(DONTNEED)
+        * because madvise is not supported on hugetlbfs. The same applies
+        * for direct IO. unmap_hugepage_range() is only being called just
+        * before free_pgtables() so clearing VM_MAYSHARE will not cause
+        * surprises later.
+        */
+       vma->vm_flags &= ~VM_MAYSHARE;
        mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
 }
 
@@ -2846,9 +2869,14 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
                }
        }
        spin_unlock(&mm->page_table_lock);
-       mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
-
+       /*
+        * Must flush TLB before releasing i_mmap_mutex: x86's huge_pmd_unshare
+        * may have cleared our pud entry and done put_page on the page table:
+        * once we release i_mmap_mutex, another task can do the final put_page
+        * and that page table be reused and filled with junk.
+        */
        flush_tlb_range(vma, start, end);
+       mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
 }
 
 int hugetlb_reserve_pages(struct inode *inode,