[PATCH 58 of 66] don't allow transparent hugepage support without PSE

Andrea Arcangeli
2010-11-03T15:36:12Z

From: Andrea Arcangeli <aarcange@redhat.com>

Archs implementing Transparent Hugepage Support must implement a
function called has_transparent_hugepage to be sure the virtual or
physical CPU supports Transparent Hugepages.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -160,6 +160,11 @@ static inline int pmd_trans_huge(pmd_t p
{
return pmd_val(pmd) & _PAGE_PSE;
}
+
+static inline int has_transparent_hugepage(void)
+{
+ return cpu_has_pse;
+}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

static inline pte_t pte_set_flags(pte_t pte, pteval_t set)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -487,7 +487,15 @@ static int __init hugepage_init(void)
int err;
#ifdef CONFIG_SYSFS
static struct kobject *hugepage_kobj;
+#endif

+ err = -EINVAL;
+ if (!has_transparent_hugepage()) {
+ transparent_hugepage_flags = 0;
+ goto out;
+ }
+
+#ifdef CONFIG_SYSFS
err = -ENOMEM;
hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);
if (unlikely(!hugepage_kobj)) {