mm: compaction: direct compact when a high-order allocation fails

[safe/jmp/linux-2.6] / mm / mempolicy.c

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 8a993db..721b2b3 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1639,6 +1639,8 @@ static inline unsigned interleave_nid(struct mempolicy *pol,
  * to the struct mempolicy for conditional unref after allocation.
  * If the effective policy is 'BIND, returns a pointer to the mempolicy's
  * @nodemask for filtering the zonelist.
+ *
+ * Must be protected by get_mems_allowed()
  */
 struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
                                gfp_t gfp_flags, struct mempolicy **mpol,
@@ -1684,6 +1686,7 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
        if (!(mask && current->mempolicy))
                return false;
 
+       task_lock(current);
        mempolicy = current->mempolicy;
        switch (mempolicy->mode) {
        case MPOL_PREFERRED:
@@ -1703,6 +1706,7 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
        default:
                BUG();
        }
+       task_unlock(current);
 
        return true;
 }
@@ -1750,13 +1754,17 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
 {
        struct mempolicy *pol = get_vma_policy(current, vma, addr);
        struct zonelist *zl;
+       struct page *page;
 
+       get_mems_allowed();
        if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
                unsigned nid;
 
                nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
                mpol_cond_put(pol);
-               return alloc_page_interleave(gfp, 0, nid);
+               page = alloc_page_interleave(gfp, 0, nid);
+               put_mems_allowed();
+               return page;
        }
        zl = policy_zonelist(gfp, pol);
        if (unlikely(mpol_needs_cond_ref(pol))) {
@@ -1766,12 +1774,15 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
                struct page *page =  __alloc_pages_nodemask(gfp, 0,
                                                zl, policy_nodemask(gfp, pol));
                __mpol_put(pol);
+               put_mems_allowed();
                return page;
        }
        /*
         * fast path:  default or task policy
         */
-       return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
+       page = __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
+       put_mems_allowed();
+       return page;
 }
 
 /**
@@ -1796,18 +1807,23 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
 struct page *alloc_pages_current(gfp_t gfp, unsigned order)
 {
        struct mempolicy *pol = current->mempolicy;
+       struct page *page;
 
        if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
                pol = &default_policy;
 
+       get_mems_allowed();
        /*
         * No reference counting needed for current->mempolicy
         * nor system default_policy
         */
        if (pol->mode == MPOL_INTERLEAVE)
-               return alloc_page_interleave(gfp, order, interleave_nodes(pol));
-       return __alloc_pages_nodemask(gfp, order,
+               page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
+       else
+               page = __alloc_pages_nodemask(gfp, order,
                        policy_zonelist(gfp, pol), policy_nodemask(gfp, pol));
+       put_mems_allowed();
+       return page;
 }
 EXPORT_SYMBOL(alloc_pages_current);