mm: define USE_SPLIT_PTLOCKS rather than repeating expression

[deliverable/linux.git] / include / linux / mm.h

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fa651609b65dbc928a1a3d20035c29b42a1a8947..4194bf8e4f6c249c5d06740a7f21396f55bf7241 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -73,7 +73,7 @@ extern unsigned int kobjsize(const void *objp);
 #endif
 
 /*
- * vm_flags..
+ * vm_flags in vm_area_struct, see mm_types.h.
  */
 #define VM_READ                0x00000001      /* currently active flags */
 #define VM_WRITE       0x00000002
@@ -919,7 +919,7 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
 }
 #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
 
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#if USE_SPLIT_PTLOCKS
 /*
  * We tuck a spinlock to guard each pagetable page into its struct page,
  * at page->private, with BUILD_BUG_ON to make sure that this will not
@@ -932,14 +932,14 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
 } while (0)
 #define pte_lock_deinit(page)  ((page)->mapping = NULL)
 #define pte_lockptr(mm, pmd)   ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
-#else
+#else  /* !USE_SPLIT_PTLOCKS */
 /*
  * We use mm->page_table_lock to guard all pagetable pages of the mm.
  */
 #define pte_lock_init(page)    do {} while (0)
 #define pte_lock_deinit(page)  do {} while (0)
 #define pte_lockptr(mm, pmd)   ({(void)(pmd); &(mm)->page_table_lock;})
-#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
+#endif /* USE_SPLIT_PTLOCKS */
 
 static inline void pgtable_page_ctor(struct page *page)
 {