mm: numa: Trap pmd hinting faults only if we would otherwise trap PTE faults

[karo-tx-linux.git] / mm / mprotect.c

diff --git a/mm/mprotect.c b/mm/mprotect.c
index f0b087d1069ce1cd5117bff5397523eab43f306f..5aae39017d6dd0af5385c04ef6c0b488900f6d8a 100644 (file)
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -146,6 +146,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 
        pmd = pmd_offset(pud, addr);
        do {
+               unsigned long this_pages;
+
                next = pmd_addr_end(addr, end);
                if (pmd_trans_huge(*pmd)) {
                        if (next - addr != HPAGE_PMD_SIZE)
@@ -165,8 +167,9 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
                }
                if (pmd_none_or_clear_bad(pmd))
                        continue;
-               pages += change_pte_range(vma, pmd, addr, next, newprot,
+               this_pages = change_pte_range(vma, pmd, addr, next, newprot,
                                 dirty_accountable, prot_numa, &all_same_nidpid);
+               pages += this_pages;
 
                /*
                 * If we are changing protections for NUMA hinting faults then
@@ -174,7 +177,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
                 * node. This allows a regular PMD to be handled as one fault
                 * and effectively batches the taking of the PTL
                 */
-               if (prot_numa && all_same_nidpid)
+               if (prot_numa && this_pages && all_same_nidpid)
                        change_pmd_protnuma(vma->vm_mm, addr, pmd);
        } while (pmd++, addr = next, addr != end);