@@ -139,6 +139,7 @@ config X86
select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
select HAVE_ARCH_PREL32_RELOCATIONS
+ select HAVE_ARCH_PTE_SWP_PGIDLE
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_THREAD_STRUCT_WHITELIST
select HAVE_ARCH_STACKLEAK
@@ -1371,6 +1371,21 @@ static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
#endif
#endif
+static inline pte_t pte_swp_mkpage_idle(pte_t pte)
+{
+ return pte_set_flags(pte, _PAGE_SWP_PGIDLE);
+}
+
+static inline int pte_swp_page_idle(pte_t pte)
+{
+ return pte_flags(pte) & _PAGE_SWP_PGIDLE;
+}
+
+static inline pte_t pte_swp_clear_mkpage_idle(pte_t pte)
+{
+ return pte_clear_flags(pte, _PAGE_SWP_PGIDLE);
+}
+
#define PKRU_AD_BIT 0x1
#define PKRU_WD_BIT 0x2
#define PKRU_BITS_PER_PKEY 2
@@ -100,6 +100,12 @@
#define _PAGE_SWP_SOFT_DIRTY (_AT(pteval_t, 0))
#endif
+#ifdef CONFIG_IDLE_PAGE_TRACKING
+#define _PAGE_SWP_PGIDLE _PAGE_USER
+#else
+#define _PAGE_SWP_PGIDLE (_AT(pteval_t, 0))
+#endif
+
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
#define _PAGE_NX (_AT(pteval_t, 1) << _PAGE_BIT_NX)
#define _PAGE_DEVMAP (_AT(u64, 1) << _PAGE_BIT_DEVMAP)
This bit will be used by idle page tracking code to correctly identify if a page that was swapped out was idle before it got swapped out. Without this PTE bit, we lose information about if a page is idle or not since the page frame gets unmapped and the page gets freed. Bits 2-6 are unused in the swap PTE (see the comment in arch/x86/include/asm/pgtable_64.h). Bit 2 corresponds to _PAGE_USER. Use it for swap PTE purposes. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- arch/x86/Kconfig | 1 + arch/x86/include/asm/pgtable.h | 15 +++++++++++++++ arch/x86/include/asm/pgtable_types.h | 6 ++++++ 3 files changed, 22 insertions(+)