thp: don't allow transparent hugepage support without PSE
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index c48ba05..18601c8 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -160,6 +160,11 @@
{
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
index b6facc3..915809b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -487,7 +487,15 @@
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)) {