mm: make CONFIG_MIGRATION available w/o CONFIG_NUMA

We'd like to support CONFIG_MEMORY_HOTREMOVE on s390, which depends on
CONFIG_MIGRATION.  So far, CONFIG_MIGRATION is only available with NUMA
support.

This patch makes CONFIG_MIGRATION selectable for architectures that define
ARCH_ENABLE_MEMORY_HOTREMOVE.  When MIGRATION is enabled w/o NUMA, the
kernel won't compile because migrate_vmas() does not know about
vm_ops->migrate() and vma_migratable() does not know about policy_zone.
To fix this, those two functions can be restricted to '#ifdef CONFIG_NUMA'
because they are not being used w/o NUMA.  vma_migratable() is moved over
from migrate.h to mempolicy.h.

[kosaki.motohiro@jp.fujitsu.com: build fix]
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: KOSAKI Motorhiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 3a39570b81b85e525bea4cde10429ac470546bbe..085c903fe0f1832ce0f46debd8ffcd3f9d5d0564 100644 (file)
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -59,6 +59,7 @@ enum {
 #include <linux/rbtree.h>
 #include <linux/spinlock.h>
 #include <linux/nodemask.h>
 #include <linux/rbtree.h>
 #include <linux/spinlock.h>
 #include <linux/nodemask.h>

+#include <linux/pagemap.h>

 
 struct mm_struct;
 
 
 struct mm_struct;
 


@@ -220,6 +221,24 @@ extern int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context);
 extern int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol,
                        int no_context);
 #endif
 extern int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol,
                        int no_context);
 #endif

+
+/* Check if a vma is migratable */
+static inline int vma_migratable(struct vm_area_struct *vma)
+{
+       if (vma->vm_flags & (VM_IO|VM_HUGETLB|VM_PFNMAP|VM_RESERVED))
+               return 0;
+       /*
+        * Migration allocates pages in the highest zone. If we cannot
+        * do so then migration (at least from node to node) is not
+        * possible.
+        */
+       if (vma->vm_file &&
+               gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
+                                                               < policy_zone)
+                       return 0;
+       return 1;
+}
+

 #else
 
 struct mempolicy {};
 #else
 
 struct mempolicy {};

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index e10a90a93b5d25a53fd12b5e623e40ffbc285bf3..03aea612d28450f24f96274c922a8da987bb918b 100644 (file)
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -3,28 +3,10 @@
 
 #include <linux/mm.h>
 #include <linux/mempolicy.h>
 
 #include <linux/mm.h>
 #include <linux/mempolicy.h>

-#include <linux/pagemap.h>

 
 typedef struct page *new_page_t(struct page *, unsigned long private, int **);
 
 #ifdef CONFIG_MIGRATION
 
 typedef struct page *new_page_t(struct page *, unsigned long private, int **);
 
 #ifdef CONFIG_MIGRATION

-/* Check if a vma is migratable */
-static inline int vma_migratable(struct vm_area_struct *vma)
-{
-       if (vma->vm_flags & (VM_IO|VM_HUGETLB|VM_PFNMAP|VM_RESERVED))
-               return 0;
-       /*
-        * Migration allocates pages in the highest zone. If we cannot
-        * do so then migration (at least from node to node) is not
-        * possible.
-        */
-       if (vma->vm_file &&
-               gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
-                                                               < policy_zone)
-                       return 0;
-       return 1;
-}
-

 extern int isolate_lru_page(struct page *p, struct list_head *pagelist);
 extern int putback_lru_pages(struct list_head *l);
 extern int migrate_page(struct address_space *,
 extern int isolate_lru_page(struct page *p, struct list_head *pagelist);
 extern int putback_lru_pages(struct list_head *l);
 extern int migrate_page(struct address_space *,


@@ -39,9 +21,6 @@ extern int migrate_vmas(struct mm_struct *mm,
                const nodemask_t *from, const nodemask_t *to,
                unsigned long flags);
 #else
                const nodemask_t *from, const nodemask_t *to,
                unsigned long flags);
 #else

-static inline int vma_migratable(struct vm_area_struct *vma)
-                                       { return 0; }
-

 static inline int isolate_lru_page(struct page *p, struct list_head *list)
                                        { return -ENOSYS; }
 static inline int putback_lru_pages(struct list_head *l) { return 0; }
 static inline int isolate_lru_page(struct page *p, struct list_head *list)
                                        { return -ENOSYS; }
 static inline int putback_lru_pages(struct list_head *l) { return 0; }

diff --git a/mm/Kconfig b/mm/Kconfig
index c4de85285bb43cd2ab9810d42c67c8001d9adb1b..aa799007a11b3bc6bfb3817a584ddce683e0c2b7 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -174,7 +174,7 @@ config SPLIT_PTLOCK_CPUS
 config MIGRATION
        bool "Page migration"
        def_bool y
 config MIGRATION
        bool "Page migration"
        def_bool y

-       depends on NUMA
+       depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE

        help
          Allows the migration of the physical location of pages of processes
          while the virtual addresses are not changed. This is useful for
        help
          Allows the migration of the physical location of pages of processes
          while the virtual addresses are not changed. This is useful for

diff --git a/mm/migrate.c b/mm/migrate.c
index e7d13a708da0b5ea4571993f85e44c9f5c0c6876..376cceba82f98e7110520acc885f6bce0687482b 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1071,7 +1071,6 @@ out2:
        mmput(mm);
        return err;
 }
        mmput(mm);
        return err;
 }

-#endif

 
 /*
  * Call migration functions in the vma_ops that may prepare
 
 /*
  * Call migration functions in the vma_ops that may prepare


@@ -1093,3 +1092,4 @@ int migrate_vmas(struct mm_struct *mm, const nodemask_t *to,
        }
        return err;
 }
        }
        return err;
 }

+#endif