[PATCH v4 04/11] mm: thp: introduce CONFIG_ARCH_ENABLE_THP_MIGRATION

From: Zi Yan
Date: Mon Mar 13 2017 - 11:49:19 EST


From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>

Introduces CONFIG_ARCH_ENABLE_THP_MIGRATION to limit thp migration
functionality to x86_64, which should be safer at the first step.

Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
---
v1 -> v2:
- fixed config name in subject and patch description
---
arch/x86/Kconfig | 4 ++++
include/linux/huge_mm.h | 10 ++++++++++
mm/Kconfig | 3 +++
3 files changed, 17 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 69188841717a..a24bc11c7aed 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2276,6 +2276,10 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION
def_bool y
depends on X86_64 && HUGETLB_PAGE && MIGRATION

+config ARCH_ENABLE_THP_MIGRATION
+ def_bool y
+ depends on X86_64 && TRANSPARENT_HUGEPAGE && MIGRATION
+
menu "Power management and ACPI options"

config ARCH_HIBERNATION_HEADER
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index a3762d49ba39..1b81cb57ff0f 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -212,6 +212,11 @@ void mm_put_huge_zero_page(struct mm_struct *mm);

#define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))

+static inline bool thp_migration_supported(void)
+{
+ return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
+}
+
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
@@ -306,6 +311,11 @@ static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
{
return NULL;
}
+
+static inline bool thp_migration_supported(void)
+{
+ return false;
+}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#endif /* _LINUX_HUGE_MM_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index 9b8fccb969dc..317a2f973720 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -289,6 +289,9 @@ config MIGRATION
config ARCH_ENABLE_HUGEPAGE_MIGRATION
bool

+config ARCH_ENABLE_THP_MIGRATION
+ bool
+
config PHYS_ADDR_T_64BIT
def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT

--
2.11.0