cpuset: mm: reduce large amounts of memory barrier related damage v3

[mirror_ubuntu-zesty-kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 62f9fada4d6de9f912cad9bfacf6cf84098914f0..b1c3148773344da4b1e90101888ea3860b3743b1 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -454,14 +454,16 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
                                struct vm_area_struct *vma,
                                unsigned long address, int avoid_reserve)
 {
-       struct page *page = NULL;
+       struct page *page;
        struct mempolicy *mpol;
        nodemask_t *nodemask;
        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)