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Commit 83d1674a authored by Gerald Schaefer's avatar Gerald Schaefer Committed by Linus Torvalds
Browse files

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: default avatarChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarKOSAKI Motorhiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9ca908f4

include/linux/mempolicy.h

+19 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ enum { 
#include <linux/rbtree.h>

#include <linux/spinlock.h>

#include <linux/nodemask.h>

#include <linux/pagemap.h>



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



/* 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 {};

include/linux/migrate.h

+0 −21
Original line number Diff line number Diff line
@@ -3,28 +3,10 @@ 


#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

/* 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 *,
@@ -39,9 +21,6 @@ extern int migrate_vmas(struct mm_struct *mm, 
		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; }

mm/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -174,7 +174,7 @@ config SPLIT_PTLOCK_CPUS 
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

mm/migrate.c

+1 −1
Original line number Diff line number Diff line
@@ -1071,7 +1071,6 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages, 
	mmput(mm);

	return err;

}

#endif



/*

 * 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;

}

#endif