From 5d1ea48bdde67898e87d6d8f511fd097fa64c749 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Wed, 10 Dec 2014 15:44:55 -0800
Subject: [PATCH] mm: page_cgroup: rename file to mm/swap_cgroup.c

Now that the external page_cgroup data structure and its lookup is gone,
the only code remaining in there is swap slot accounting.

Rename it and move the conditional compilation into mm/Makefile.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Tejun Heo <tj@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 MAINTAINERS                                    | 2 +-
 include/linux/{page_cgroup.h => swap_cgroup.h} | 8 +++++---
 mm/Makefile                                    | 3 ++-
 mm/memcontrol.c                                | 2 +-
 mm/{page_cgroup.c => swap_cgroup.c}            | 9 +++------
 mm/swap_state.c                                | 1 -
 mm/swapfile.c                                  | 2 +-
 7 files changed, 13 insertions(+), 14 deletions(-)
 rename include/linux/{page_cgroup.h => swap_cgroup.h} (88%)
 rename mm/{page_cgroup.c => swap_cgroup.c} (98%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 0d6469a2cf70..0aedd3e1804b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2606,7 +2606,7 @@ L:	cgroups@vger.kernel.org
 L:	linux-mm@kvack.org
 S:	Maintained
 F:	mm/memcontrol.c
-F:	mm/page_cgroup.c
+F:	mm/swap_cgroup.c
 
 CORETEMP HARDWARE MONITORING DRIVER
 M:	Fenghua Yu <fenghua.yu@intel.com>
diff --git a/include/linux/page_cgroup.h b/include/linux/swap_cgroup.h
similarity index 88%
rename from include/linux/page_cgroup.h
rename to include/linux/swap_cgroup.h
index 65be35785c86..145306bdc92f 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/swap_cgroup.h
@@ -1,15 +1,17 @@
-#ifndef __LINUX_PAGE_CGROUP_H
-#define __LINUX_PAGE_CGROUP_H
+#ifndef __LINUX_SWAP_CGROUP_H
+#define __LINUX_SWAP_CGROUP_H
 
 #include <linux/swap.h>
 
 #ifdef CONFIG_MEMCG_SWAP
+
 extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
 					unsigned short old, unsigned short new);
 extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
 extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent);
 extern int swap_cgroup_swapon(int type, unsigned long max_pages);
 extern void swap_cgroup_swapoff(int type);
+
 #else
 
 static inline
@@ -37,4 +39,4 @@ static inline void swap_cgroup_swapoff(int type)
 
 #endif /* CONFIG_MEMCG_SWAP */
 
-#endif /* __LINUX_PAGE_CGROUP_H */
+#endif /* __LINUX_SWAP_CGROUP_H */
diff --git a/mm/Makefile b/mm/Makefile
index 6d9f40e922f7..b3c6ce932c64 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -56,7 +56,8 @@ obj-$(CONFIG_MIGRATION) += migrate.o
 obj-$(CONFIG_QUICKLIST) += quicklist.o
 obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o
 obj-$(CONFIG_PAGE_COUNTER) += page_counter.o
-obj-$(CONFIG_MEMCG) += memcontrol.o page_cgroup.o vmpressure.o
+obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o
+obj-$(CONFIG_MEMCG_SWAP) += swap_cgroup.o
 obj-$(CONFIG_CGROUP_HUGETLB) += hugetlb_cgroup.o
 obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
 obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b864067791dc..ab270e34ba3e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -51,7 +51,7 @@
 #include <linux/seq_file.h>
 #include <linux/vmpressure.h>
 #include <linux/mm_inline.h>
-#include <linux/page_cgroup.h>
+#include <linux/swap_cgroup.h>
 #include <linux/cpu.h>
 #include <linux/oom.h>
 #include <linux/lockdep.h>
diff --git a/mm/page_cgroup.c b/mm/swap_cgroup.c
similarity index 98%
rename from mm/page_cgroup.c
rename to mm/swap_cgroup.c
index f0f31c1d4d0c..b5f7f24b8dd1 100644
--- a/mm/page_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -1,9 +1,8 @@
-#include <linux/mm.h>
-#include <linux/page_cgroup.h>
+#include <linux/swap_cgroup.h>
 #include <linux/vmalloc.h>
-#include <linux/swapops.h>
+#include <linux/mm.h>
 
-#ifdef CONFIG_MEMCG_SWAP
+#include <linux/swapops.h> /* depends on mm.h include */
 
 static DEFINE_MUTEX(swap_cgroup_mutex);
 struct swap_cgroup_ctrl {
@@ -207,5 +206,3 @@ void swap_cgroup_swapoff(int type)
 		vfree(map);
 	}
 }
-
-#endif
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 154444918685..9711342987a0 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -17,7 +17,6 @@
 #include <linux/blkdev.h>
 #include <linux/pagevec.h>
 #include <linux/migrate.h>
-#include <linux/page_cgroup.h>
 
 #include <asm/pgtable.h>
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 8798b2e0ac59..63f55ccb9b26 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -38,7 +38,7 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 #include <linux/swapops.h>
-#include <linux/page_cgroup.h>
+#include <linux/swap_cgroup.h>
 
 static bool swap_count_continued(struct swap_info_struct *, pgoff_t,
 				 unsigned char);
-- 
2.20.1