mm/THP: deposit the transpare huge pgtable before set_pmd
authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Thu, 6 Jun 2013 00:14:06 +0000 (17:14 -0700)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>
Thu, 20 Jun 2013 06:55:08 +0000 (16:55 +1000)
Architectures like powerpc use the deposited pgtable to store hash index
values.  We need to make the deposted pgtable is visible to other cpus
before we are ready to take a hash fault.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
mm/huge_memory.c

index 5c4fac2d239e5ce28858d550745fa249070824e7..59d9384b6bbfe3392b9c7b7b9f901a8fc89a46c8 100644 (file)
@@ -729,8 +729,8 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
                pmd_t entry;
                entry = mk_huge_pmd(page, vma);
                page_add_new_anon_rmap(page, vma, haddr);
-               set_pmd_at(mm, haddr, pmd, entry);
                pgtable_trans_huge_deposit(mm, pmd, pgtable);
+               set_pmd_at(mm, haddr, pmd, entry);
                add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
                mm->nr_ptes++;
                spin_unlock(&mm->page_table_lock);
@@ -771,8 +771,8 @@ static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
        entry = mk_pmd(zero_page, vma->vm_page_prot);
        entry = pmd_wrprotect(entry);
        entry = pmd_mkhuge(entry);
-       set_pmd_at(mm, haddr, pmd, entry);
        pgtable_trans_huge_deposit(mm, pmd, pgtable);
+       set_pmd_at(mm, haddr, pmd, entry);
        mm->nr_ptes++;
        return true;
 }
@@ -916,8 +916,8 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 
        pmdp_set_wrprotect(src_mm, addr, src_pmd);
        pmd = pmd_mkold(pmd_wrprotect(pmd));
-       set_pmd_at(dst_mm, addr, dst_pmd, pmd);
        pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
+       set_pmd_at(dst_mm, addr, dst_pmd, pmd);
        dst_mm->nr_ptes++;
 
        ret = 0;
@@ -2367,9 +2367,9 @@ static void collapse_huge_page(struct mm_struct *mm,
        spin_lock(&mm->page_table_lock);
        BUG_ON(!pmd_none(*pmd));
        page_add_new_anon_rmap(new_page, vma, address);
+       pgtable_trans_huge_deposit(mm, pmd, pgtable);
        set_pmd_at(mm, address, pmd, _pmd);
        update_mmu_cache_pmd(vma, address, pmd);
-       pgtable_trans_huge_deposit(mm, pmd, pgtable);
        spin_unlock(&mm->page_table_lock);
 
        *hpage = NULL;