Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...

[deliverable/linux.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 90eef404ec2e81179077d3d7c6e35eba9aedfc48..615d9743a3cbad1ca19d745c45115eecb1c463f4 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1771,12 +1771,9 @@ static void collapse_huge_page(struct mm_struct *mm,
 
        VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 #ifndef CONFIG_NUMA
+       up_read(&mm->mmap_sem);
        VM_BUG_ON(!*hpage);
        new_page = *hpage;
-       if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
-               up_read(&mm->mmap_sem);
-               return;
-       }
 #else
        VM_BUG_ON(*hpage);
        /*
@@ -1791,22 +1788,26 @@ static void collapse_huge_page(struct mm_struct *mm,
         */
        new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address,
                                      node, __GFP_OTHER_NODE);
+
+       /*
+        * After allocating the hugepage, release the mmap_sem read lock in
+        * preparation for taking it in write mode.
+        */
+       up_read(&mm->mmap_sem);
        if (unlikely(!new_page)) {
-               up_read(&mm->mmap_sem);
                count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
                *hpage = ERR_PTR(-ENOMEM);
                return;
        }
+#endif
+
        count_vm_event(THP_COLLAPSE_ALLOC);
        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
-               up_read(&mm->mmap_sem);
+#ifdef CONFIG_NUMA
                put_page(new_page);
+#endif
                return;
        }
-#endif
-
-       /* after allocating the hugepage upgrade to mmap_sem write mode */
-       up_read(&mm->mmap_sem);
 
        /*
         * Prevent all access to pagetables with the exception of