--- arch/x86/mm/init.c

+++ arch/x86/mm/init.c

@@ -287,6 +287,25 @@ unsigned long __init_refok init_memory_m

load_cr3(swapper_pg_dir);

#endif

+#ifdef CONFIG_X86_64

+ if (!after_bootmem && !start) {

+ pud_t *pud;

+ pmd_t *pmd;

+

+ mmu_cr4_features = read_cr4();

+

+ /*

+ * _brk_end cannot change anymore, but it and _end may be

+ * located on different 2M pages. cleanup_highmap(), however,

+ * can only consider _end when it runs, so destroy any

+ * mappings beyond _brk_end here.

+ */

+ pud = pud_offset(pgd_offset_k(_brk_end), _brk_end);

+ pmd = pmd_offset(pud, _brk_end - 1);

+ while (++pmd <= pmd_offset(pud, (unsigned long)_end - 1))

+ pmd_clear(pmd);

+ }

+#endif

__flush_tlb_all();

if (!after_bootmem && e820_table_end > e820_table_start)