mm: define USE_SPLIT_PTLOCKS rather than repeating expression

Define USE_SPLIT_PTLOCKS as a constant expression rather than repeating
"NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS" all over the place.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index aa37469da69691cba0eca23089a517dcab26351a..2e1b6408849019d8a24ef7e45f18136f55c902bc 100644 (file)
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -646,7 +646,7 @@ static spinlock_t *lock_pte(struct page *page)
 {
        spinlock_t *ptl = NULL;
 
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#if USE_SPLIT_PTLOCKS
        ptl = __pte_lockptr(page);
        spin_lock(ptl);
 #endif

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 72a15dc26bbf399bb891f01f740283e723929b33..4194bf8e4f6c249c5d06740a7f21396f55bf7241 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -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)
 {

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index bf334138c7c148da4c9ec7b409254045de0d327b..9d49fa36bbeff3237e2e0f4925a0ed3ac1ec1b29 100644 (file)
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -21,11 +21,13 @@
 
 struct address_space;
 
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#define USE_SPLIT_PTLOCKS      (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
+
+#if USE_SPLIT_PTLOCKS
 typedef atomic_long_t mm_counter_t;
-#else  /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
+#else  /* !USE_SPLIT_PTLOCKS */
 typedef unsigned long mm_counter_t;
-#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
+#endif /* !USE_SPLIT_PTLOCKS */
 
 /*
  * Each physical page in the system has a struct page associated with
@@ -65,7 +67,7 @@ struct page {
                                                 * see PAGE_MAPPING_ANON below.
                                                 */
            };
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#if USE_SPLIT_PTLOCKS
            spinlock_t ptl;
 #endif
            struct kmem_cache *slab;    /* SLUB: Pointer to slab */

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3d9120c5ad1589a0da722e514c370c0a3f1c4fe4..272c35309df2762e381677deca00ee19ca3bdcff 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -352,7 +352,7 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 extern void arch_unmap_area(struct mm_struct *, unsigned long);
 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
 
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#if USE_SPLIT_PTLOCKS
 /*
  * The mm counters are not protected by its page_table_lock,
  * so must be incremented atomically.
@@ -363,7 +363,7 @@ extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
 #define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
 #define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
 
-#else  /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
+#else  /* !USE_SPLIT_PTLOCKS */
 /*
  * The mm counters are protected by its page_table_lock,
  * so can be incremented directly.
@@ -374,7 +374,7 @@ extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
 #define inc_mm_counter(mm, member) (mm)->_##member++
 #define dec_mm_counter(mm, member) (mm)->_##member--
 
-#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
+#endif /* !USE_SPLIT_PTLOCKS */
 
 #define get_mm_rss(mm)                                 \
        (get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))