Re: [PATCH 6/8] Direct Migration V2: Avoid writeback / page_migrate() method

Christoph Lameter
2005-11-09T19:14:25Z

On Wed, 9 Nov 2005, Nikita Danilov wrote:

> buffer_migrate_page is a pointer to function.
>
> buffer_migrate_page(a, b) is a value of type int (or void *).

Yup that is wrong. It must be

#define buffer_migrate_page NULL

While investigating that I found a name clash and some issues with #ifdef
CONFIG_MIGRATION for direct migration. Sigh.

===

Fix UP compile

- Remove parameters from macro definitions for migration function
if CONFIG_MIGRATION is off.

- Avoid name clash between migrate_page macro and the address operations
field names migrate_page by renaming it to migratepage.

- Adjust #ifdef CONFIG_MIGRATION in vmscan.c to include
fail_migrate_page (provide by macro if !CONFIG_MIGRATION and
surround putback_lru_pages() with #ifdef CONFIG_MIGRATION

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.14-mm1/mm/vmscan.c
===================================================================
--- linux-2.6.14-mm1.orig/mm/vmscan.c 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/mm/vmscan.c 2005-11-09 11:08:31.000000000 -0800
@@ -572,6 +572,7 @@ keep:
return reclaimed;
}

+#ifdef CONFIG_MIGRATION
/*
* Non migratable page
*/
@@ -580,8 +581,6 @@ int fail_migrate_page(struct page *newpa
return -EIO;
}

-
-#ifdef CONFIG_MIGRATION
/*
* swapout a single page
* page is locked upon entry, unlocked on exit
@@ -916,8 +916,8 @@ redo:
if (!mapping)
goto unlock_both;

- if (mapping->a_ops->migrate_page) {
- rc = mapping->a_ops->migrate_page(newpage, page);
+ if (mapping->a_ops->migratepage) {
+ rc = mapping->a_ops->migratepage(newpage, page);
goto unlock_both;
}

@@ -1142,6 +1142,7 @@ done:
pagevec_release(&pvec);
}

+#ifdef CONFIG_MIGRATION
/*
* Add isolated pages on the list back to the LRU
*
@@ -1159,6 +1160,7 @@ int putback_lru_pages(struct list_head *
}
return count;
}
+#endif

/*
* This moves pages from the active list to the inactive list.
Index: linux-2.6.14-mm1/include/linux/fs.h
===================================================================
--- linux-2.6.14-mm1.orig/include/linux/fs.h 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/include/linux/fs.h 2005-11-09 10:54:03.000000000 -0800
@@ -333,7 +333,7 @@ struct address_space_operations {
struct page* (*get_xip_page)(struct address_space *, sector_t,
int);
/* migrate the contents of a page to the specified target */
- int (*migrate_page) (struct page *, struct page *);
+ int (*migratepage) (struct page *, struct page *);
};

struct backing_dev_info;
@@ -1684,7 +1684,7 @@ extern ssize_t simple_read_from_buffer(v
#ifdef CONFIG_MIGRATION
extern int buffer_migrate_page(struct page *, struct page *);
#else
-#define buffer_migrate_page(a,b) NULL
+#define buffer_migrate_page NULL
#endif

extern int inode_change_ok(struct inode *, struct iattr *);
Index: linux-2.6.14-mm1/include/linux/swap.h
===================================================================
--- linux-2.6.14-mm1.orig/include/linux/swap.h 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/include/linux/swap.h 2005-11-09 10:54:03.000000000 -0800
@@ -189,8 +189,8 @@ extern void migrate_page_copy(struct pag
extern int fail_migrate_page(struct page *, struct page *);
#else
/* Possible settings for the migrate_page() method in address_operations */
-#define migrate_page(a,b) NULL
-#define fail_migrate_page(a,b) NULL
+#define migrate_page NULL
+#define fail_migrate_page NULL
#endif

#ifdef CONFIG_MMU
Index: linux-2.6.14-mm1/mm/swap_state.c
===================================================================
--- linux-2.6.14-mm1.orig/mm/swap_state.c 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/mm/swap_state.c 2005-11-09 10:54:03.000000000 -0800
@@ -26,7 +26,7 @@ static struct address_space_operations s
.writepage = swap_writepage,
.sync_page = block_sync_page,
.set_page_dirty = __set_page_dirty_nobuffers,
- .migrate_page = migrate_page,
+ .migratepage = migrate_page,
};

static struct backing_dev_info swap_backing_dev_info = {
Index: linux-2.6.14-mm1/fs/ext2/inode.c
===================================================================
--- linux-2.6.14-mm1.orig/fs/ext2/inode.c 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/fs/ext2/inode.c 2005-11-09 10:54:03.000000000 -0800
@@ -706,7 +706,7 @@ struct address_space_operations ext2_aop
.bmap = ext2_bmap,
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
- .migrate_page = buffer_migrate_page,
+ .migratepage = buffer_migrate_page,
};

struct address_space_operations ext2_aops_xip = {
@@ -724,7 +724,7 @@ struct address_space_operations ext2_nob
.bmap = ext2_bmap,
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
- .migrate_page = buffer_migrate_page,
+ .migratepage = buffer_migrate_page,
};

/*
Index: linux-2.6.14-mm1/fs/ext3/inode.c
===================================================================
--- linux-2.6.14-mm1.orig/fs/ext3/inode.c 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/fs/ext3/inode.c 2005-11-09 10:54:03.000000000 -0800
@@ -1562,7 +1562,7 @@ static struct address_space_operations e
.invalidatepage = ext3_invalidatepage,
.releasepage = ext3_releasepage,
.direct_IO = ext3_direct_IO,
- .migrate_page = buffer_migrate_page,
+ .migratepage = buffer_migrate_page,
};

static struct address_space_operations ext3_writeback_aops = {
@@ -1576,7 +1576,7 @@ static struct address_space_operations e
.invalidatepage = ext3_invalidatepage,
.releasepage = ext3_releasepage,
.direct_IO = ext3_direct_IO,
- .migrate_page = buffer_migrate_page,
+ .migratepage = buffer_migrate_page,
};

static struct address_space_operations ext3_journalled_aops = {
Index: linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_aops.c
===================================================================
--- linux-2.6.14-mm1.orig/fs/xfs/linux-2.6/xfs_aops.c 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_aops.c 2005-11-09 10:54:03.000000000 -0800
@@ -1348,5 +1348,5 @@ struct address_space_operations linvfs_a
.commit_write = generic_commit_write,
.bmap = linvfs_bmap,
.direct_IO = linvfs_direct_IO,
- .migrate_page = buffer_migrate_page,
+ .migratepage = buffer_migrate_page,
};
Index: linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_buf.c
===================================================================
--- linux-2.6.14-mm1.orig/fs/xfs/linux-2.6/xfs_buf.c 2005-11-09 10:54:03.000000000 -0800
+++ linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_buf.c 2005-11-09 10:59:39.000000000 -0800
@@ -1568,7 +1568,7 @@ xfs_mapping_buftarg(
struct address_space *mapping;
static struct address_space_operations mapping_aops = {
.sync_page = block_sync_page,
- .migrate_page = fail_migrate_page,
+ .migratepage = fail_migrate_page,
};

inode = new_inode(bdev->bd_inode->i_sb);