mm: fix build warnings in <linux/compaction.h>

Randy reported below build error.

> In file included from ../include/linux/balloon_compaction.h:48:0,
>                  from ../mm/balloon_compaction.c:11:
> ../include/linux/compaction.h:237:51: warning: 'struct node' declared inside parameter list [enabled by default]
>  static inline int compaction_register_node(struct node *node)
> ../include/linux/compaction.h:237:51: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
> ../include/linux/compaction.h:242:54: warning: 'struct node' declared inside parameter list [enabled by default]
>  static inline void compaction_unregister_node(struct node *node)
>

It was caused by non-lru page migration which needs compaction.h but
compaction.h doesn't include any header to be standalone.

I think proper header for non-lru page migration is migrate.h rather
than compaction.h because migrate.h has already headers needed to work
non-lru page migration indirectly like isolate_mode_t, migrate_mode
MIGRATEPAGE_SUCCESS.

[akpm@linux-foundation.org: revert mm-balloon-use-general-non-lru-movable-page-feature-fix.patch temp fix]
Link: http://lkml.kernel.org/r/20160610003304.GE29779@bbox
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/vm/page_migration b/Documentation/vm/page_migration
index 18d37c7ac50bba3cc9fe8555347c16396f3d8a7b..94bd9c11c4e00cdf750bfeb4a9836f8f3ac9cf2f 100644 (file)
--- a/Documentation/vm/page_migration
+++ b/Documentation/vm/page_migration
@@ -181,11 +181,12 @@ After isolation, VM calls migratepage of driver with isolated page.
 The function of migratepage is to move content of the old page to new page
 and set up fields of struct page newpage. Keep in mind that you should
 indicate to the VM the oldpage is no longer movable via __ClearPageMovable()
-under page_lock if you migrated the oldpage successfully and returns 0.
-If driver cannot migrate the page at the moment, driver can return -EAGAIN.
-On -EAGAIN, VM will retry page migration in a short time because VM interprets
--EAGAIN as "temporal migration failure". On returning any error except -EAGAIN,
-VM will give up the page migration without retrying in this time.
+under page_lock if you migrated the oldpage successfully and returns
+MIGRATEPAGE_SUCCESS. If driver cannot migrate the page at the moment, driver
+can return -EAGAIN. On -EAGAIN, VM will retry page migration in a short time
+because VM interprets -EAGAIN as "temporal migration failure". On returning
+any error except -EAGAIN, VM will give up the page migration without retrying
+in this time.
 
 Driver shouldn't touch page.lru field VM using in the functions.
 

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 88d5609375de1cbf85a6962a9f0335431cc4717a..888d5f8322cea8b007d45ca8f191cfb560763027 100644 (file)
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -493,7 +493,7 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info,
 
        put_page(page); /* balloon reference */
 
-       return 0;
+       return MIGRATEPAGE_SUCCESS;
 }
 
 static struct dentry *balloon_mount(struct file_system_type *fs_type,

diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
index 504bd724e6ab3fe9592ad02836ab455a2c09d8f7..79542b2698ec7bae9f915fd6b7f2fefa5891e5a3 100644 (file)
--- a/include/linux/balloon_compaction.h
+++ b/include/linux/balloon_compaction.h
@@ -45,8 +45,7 @@
 #define _LINUX_BALLOON_COMPACTION_H
 #include <linux/pagemap.h>
 #include <linux/page-flags.h>
-#include <linux/node.h>
-#include <linux/compaction.h>
+#include <linux/migrate.h>
 #include <linux/gfp.h>
 #include <linux/err.h>
 #include <linux/fs.h>

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index c6b47c861ceaaf19759e336862cb81611224ca32..1a02dab16646ebc8917a71cc52b0a5491bd49b1c 100644 (file)
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -54,9 +54,6 @@ enum compact_result {
 struct alloc_context; /* in mm/internal.h */
 
 #ifdef CONFIG_COMPACTION
-extern int PageMovable(struct page *page);
-extern void __SetPageMovable(struct page *page, struct address_space *mapping);
-extern void __ClearPageMovable(struct page *page);
 extern int sysctl_compact_memory;
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
                        void __user *buffer, size_t *length, loff_t *ppos);
@@ -154,19 +151,6 @@ extern void kcompactd_stop(int nid);
 extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx);
 
 #else
-static inline int PageMovable(struct page *page)
-{
-       return 0;
-}
-static inline void __SetPageMovable(struct page *page,
-                       struct address_space *mapping)
-{
-}
-
-static inline void __ClearPageMovable(struct page *page)
-{
-}
-
 static inline enum compact_result try_to_compact_pages(gfp_t gfp_mask,
                        unsigned int order, int alloc_flags,
                        const struct alloc_context *ac,

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 404fbfefeb33036358c9af91b5ee795911e08c59..ae8d475a9385226a7af27a39d40a10937b0721e0 100644 (file)
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -71,6 +71,21 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
 
 #endif /* CONFIG_MIGRATION */
 
+#ifdef CONFIG_COMPACTION
+extern int PageMovable(struct page *page);
+extern void __SetPageMovable(struct page *page, struct address_space *mapping);
+extern void __ClearPageMovable(struct page *page);
+#else
+static inline int PageMovable(struct page *page) { return 0; };
+static inline void __SetPageMovable(struct page *page,
+                               struct address_space *mapping)
+{
+}
+static inline void __ClearPageMovable(struct page *page)
+{
+}
+#endif
+
 #ifdef CONFIG_NUMA_BALANCING
 extern bool pmd_trans_migrating(pmd_t pmd);
 extern int migrate_misplaced_page(struct page *page,

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index e4e8081b160b56c7fe7ceb1c842bc6ef9bd7d0bf..04176de6df705510b1da24ea6001174cbe1b46d8 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -50,7 +50,7 @@
 #include <linux/zsmalloc.h>
 #include <linux/zpool.h>
 #include <linux/mount.h>
-#include <linux/compaction.h>
+#include <linux/migrate.h>
 #include <linux/pagemap.h>
 
 #define ZSPAGE_MAGIC   0x58
@@ -2107,7 +2107,7 @@ int zs_page_migrate(struct address_space *mapping, struct page *newpage,
        put_page(page);
        page = newpage;
 
-       ret = 0;
+       ret = MIGRATEPAGE_SUCCESS;
 unpin_objects:
        for (addr = s_addr + offset; addr < s_addr + pos;
                                                addr += class->size) {