mm: page_cgroup: rename file to mm/swap_cgroup.c
authorJohannes Weiner <hannes@cmpxchg.org>
Wed, 10 Dec 2014 23:44:55 +0000 (15:44 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 11 Dec 2014 01:41:09 +0000 (17:41 -0800)
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
include/linux/page_cgroup.h [deleted file]
include/linux/swap_cgroup.h [new file with mode: 0644]
mm/Makefile
mm/memcontrol.c
mm/page_cgroup.c [deleted file]
mm/swap_cgroup.c [new file with mode: 0644]
mm/swap_state.c
mm/swapfile.c

index 0d6469a..0aedd3e 100644 (file)
@@ -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/page_cgroup.h
deleted file mode 100644 (file)
index 65be357..0000000
+++ /dev/null
@@ -1,40 +0,0 @@
-#ifndef __LINUX_PAGE_CGROUP_H
-#define __LINUX_PAGE_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
-unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
-{
-       return 0;
-}
-
-static inline
-unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
-{
-       return 0;
-}
-
-static inline int
-swap_cgroup_swapon(int type, unsigned long max_pages)
-{
-       return 0;
-}
-
-static inline void swap_cgroup_swapoff(int type)
-{
-       return;
-}
-
-#endif /* CONFIG_MEMCG_SWAP */
-
-#endif /* __LINUX_PAGE_CGROUP_H */
diff --git a/include/linux/swap_cgroup.h b/include/linux/swap_cgroup.h
new file mode 100644 (file)
index 0000000..145306b
--- /dev/null
@@ -0,0 +1,42 @@
+#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
+unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
+{
+       return 0;
+}
+
+static inline
+unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
+{
+       return 0;
+}
+
+static inline int
+swap_cgroup_swapon(int type, unsigned long max_pages)
+{
+       return 0;
+}
+
+static inline void swap_cgroup_swapoff(int type)
+{
+       return;
+}
+
+#endif /* CONFIG_MEMCG_SWAP */
+
+#endif /* __LINUX_SWAP_CGROUP_H */
index 6d9f40e..b3c6ce9 100644 (file)
@@ -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
index b864067..ab270e3 100644 (file)
@@ -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/page_cgroup.c
deleted file mode 100644 (file)
index f0f31c1..0000000
+++ /dev/null
@@ -1,211 +0,0 @@
-#include <linux/mm.h>
-#include <linux/page_cgroup.h>
-#include <linux/vmalloc.h>
-#include <linux/swapops.h>
-
-#ifdef CONFIG_MEMCG_SWAP
-
-static DEFINE_MUTEX(swap_cgroup_mutex);
-struct swap_cgroup_ctrl {
-       struct page **map;
-       unsigned long length;
-       spinlock_t      lock;
-};
-
-static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
-
-struct swap_cgroup {
-       unsigned short          id;
-};
-#define SC_PER_PAGE    (PAGE_SIZE/sizeof(struct swap_cgroup))
-
-/*
- * SwapCgroup implements "lookup" and "exchange" operations.
- * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
- * against SwapCache. At swap_free(), this is accessed directly from swap.
- *
- * This means,
- *  - we have no race in "exchange" when we're accessed via SwapCache because
- *    SwapCache(and its swp_entry) is under lock.
- *  - When called via swap_free(), there is no user of this entry and no race.
- * Then, we don't need lock around "exchange".
- *
- * TODO: we can push these buffers out to HIGHMEM.
- */
-
-/*
- * allocate buffer for swap_cgroup.
- */
-static int swap_cgroup_prepare(int type)
-{
-       struct page *page;
-       struct swap_cgroup_ctrl *ctrl;
-       unsigned long idx, max;
-
-       ctrl = &swap_cgroup_ctrl[type];
-
-       for (idx = 0; idx < ctrl->length; idx++) {
-               page = alloc_page(GFP_KERNEL | __GFP_ZERO);
-               if (!page)
-                       goto not_enough_page;
-               ctrl->map[idx] = page;
-       }
-       return 0;
-not_enough_page:
-       max = idx;
-       for (idx = 0; idx < max; idx++)
-               __free_page(ctrl->map[idx]);
-
-       return -ENOMEM;
-}
-
-static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
-                                       struct swap_cgroup_ctrl **ctrlp)
-{
-       pgoff_t offset = swp_offset(ent);
-       struct swap_cgroup_ctrl *ctrl;
-       struct page *mappage;
-       struct swap_cgroup *sc;
-
-       ctrl = &swap_cgroup_ctrl[swp_type(ent)];
-       if (ctrlp)
-               *ctrlp = ctrl;
-
-       mappage = ctrl->map[offset / SC_PER_PAGE];
-       sc = page_address(mappage);
-       return sc + offset % SC_PER_PAGE;
-}
-
-/**
- * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
- * @ent: swap entry to be cmpxchged
- * @old: old id
- * @new: new id
- *
- * Returns old id at success, 0 at failure.
- * (There is no mem_cgroup using 0 as its id)
- */
-unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
-                                       unsigned short old, unsigned short new)
-{
-       struct swap_cgroup_ctrl *ctrl;
-       struct swap_cgroup *sc;
-       unsigned long flags;
-       unsigned short retval;
-
-       sc = lookup_swap_cgroup(ent, &ctrl);
-
-       spin_lock_irqsave(&ctrl->lock, flags);
-       retval = sc->id;
-       if (retval == old)
-               sc->id = new;
-       else
-               retval = 0;
-       spin_unlock_irqrestore(&ctrl->lock, flags);
-       return retval;
-}
-
-/**
- * swap_cgroup_record - record mem_cgroup for this swp_entry.
- * @ent: swap entry to be recorded into
- * @id: mem_cgroup to be recorded
- *
- * Returns old value at success, 0 at failure.
- * (Of course, old value can be 0.)
- */
-unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
-{
-       struct swap_cgroup_ctrl *ctrl;
-       struct swap_cgroup *sc;
-       unsigned short old;
-       unsigned long flags;
-
-       sc = lookup_swap_cgroup(ent, &ctrl);
-
-       spin_lock_irqsave(&ctrl->lock, flags);
-       old = sc->id;
-       sc->id = id;
-       spin_unlock_irqrestore(&ctrl->lock, flags);
-
-       return old;
-}
-
-/**
- * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry
- * @ent: swap entry to be looked up.
- *
- * Returns ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
- */
-unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
-{
-       return lookup_swap_cgroup(ent, NULL)->id;
-}
-
-int swap_cgroup_swapon(int type, unsigned long max_pages)
-{
-       void *array;
-       unsigned long array_size;
-       unsigned long length;
-       struct swap_cgroup_ctrl *ctrl;
-
-       if (!do_swap_account)
-               return 0;
-
-       length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
-       array_size = length * sizeof(void *);
-
-       array = vzalloc(array_size);
-       if (!array)
-               goto nomem;
-
-       ctrl = &swap_cgroup_ctrl[type];
-       mutex_lock(&swap_cgroup_mutex);
-       ctrl->length = length;
-       ctrl->map = array;
-       spin_lock_init(&ctrl->lock);
-       if (swap_cgroup_prepare(type)) {
-               /* memory shortage */
-               ctrl->map = NULL;
-               ctrl->length = 0;
-               mutex_unlock(&swap_cgroup_mutex);
-               vfree(array);
-               goto nomem;
-       }
-       mutex_unlock(&swap_cgroup_mutex);
-
-       return 0;
-nomem:
-       printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
-       printk(KERN_INFO
-               "swap_cgroup can be disabled by swapaccount=0 boot option\n");
-       return -ENOMEM;
-}
-
-void swap_cgroup_swapoff(int type)
-{
-       struct page **map;
-       unsigned long i, length;
-       struct swap_cgroup_ctrl *ctrl;
-
-       if (!do_swap_account)
-               return;
-
-       mutex_lock(&swap_cgroup_mutex);
-       ctrl = &swap_cgroup_ctrl[type];
-       map = ctrl->map;
-       length = ctrl->length;
-       ctrl->map = NULL;
-       ctrl->length = 0;
-       mutex_unlock(&swap_cgroup_mutex);
-
-       if (map) {
-               for (i = 0; i < length; i++) {
-                       struct page *page = map[i];
-                       if (page)
-                               __free_page(page);
-               }
-               vfree(map);
-       }
-}
-
-#endif
diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
new file mode 100644 (file)
index 0000000..b5f7f24
--- /dev/null
@@ -0,0 +1,208 @@
+#include <linux/swap_cgroup.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+
+#include <linux/swapops.h> /* depends on mm.h include */
+
+static DEFINE_MUTEX(swap_cgroup_mutex);
+struct swap_cgroup_ctrl {
+       struct page **map;
+       unsigned long length;
+       spinlock_t      lock;
+};
+
+static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
+
+struct swap_cgroup {
+       unsigned short          id;
+};
+#define SC_PER_PAGE    (PAGE_SIZE/sizeof(struct swap_cgroup))
+
+/*
+ * SwapCgroup implements "lookup" and "exchange" operations.
+ * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
+ * against SwapCache. At swap_free(), this is accessed directly from swap.
+ *
+ * This means,
+ *  - we have no race in "exchange" when we're accessed via SwapCache because
+ *    SwapCache(and its swp_entry) is under lock.
+ *  - When called via swap_free(), there is no user of this entry and no race.
+ * Then, we don't need lock around "exchange".
+ *
+ * TODO: we can push these buffers out to HIGHMEM.
+ */
+
+/*
+ * allocate buffer for swap_cgroup.
+ */
+static int swap_cgroup_prepare(int type)
+{
+       struct page *page;
+       struct swap_cgroup_ctrl *ctrl;
+       unsigned long idx, max;
+
+       ctrl = &swap_cgroup_ctrl[type];
+
+       for (idx = 0; idx < ctrl->length; idx++) {
+               page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+               if (!page)
+                       goto not_enough_page;
+               ctrl->map[idx] = page;
+       }
+       return 0;
+not_enough_page:
+       max = idx;
+       for (idx = 0; idx < max; idx++)
+               __free_page(ctrl->map[idx]);
+
+       return -ENOMEM;
+}
+
+static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
+                                       struct swap_cgroup_ctrl **ctrlp)
+{
+       pgoff_t offset = swp_offset(ent);
+       struct swap_cgroup_ctrl *ctrl;
+       struct page *mappage;
+       struct swap_cgroup *sc;
+
+       ctrl = &swap_cgroup_ctrl[swp_type(ent)];
+       if (ctrlp)
+               *ctrlp = ctrl;
+
+       mappage = ctrl->map[offset / SC_PER_PAGE];
+       sc = page_address(mappage);
+       return sc + offset % SC_PER_PAGE;
+}
+
+/**
+ * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
+ * @ent: swap entry to be cmpxchged
+ * @old: old id
+ * @new: new id
+ *
+ * Returns old id at success, 0 at failure.
+ * (There is no mem_cgroup using 0 as its id)
+ */
+unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
+                                       unsigned short old, unsigned short new)
+{
+       struct swap_cgroup_ctrl *ctrl;
+       struct swap_cgroup *sc;
+       unsigned long flags;
+       unsigned short retval;
+
+       sc = lookup_swap_cgroup(ent, &ctrl);
+
+       spin_lock_irqsave(&ctrl->lock, flags);
+       retval = sc->id;
+       if (retval == old)
+               sc->id = new;
+       else
+               retval = 0;
+       spin_unlock_irqrestore(&ctrl->lock, flags);
+       return retval;
+}
+
+/**
+ * swap_cgroup_record - record mem_cgroup for this swp_entry.
+ * @ent: swap entry to be recorded into
+ * @id: mem_cgroup to be recorded
+ *
+ * Returns old value at success, 0 at failure.
+ * (Of course, old value can be 0.)
+ */
+unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
+{
+       struct swap_cgroup_ctrl *ctrl;
+       struct swap_cgroup *sc;
+       unsigned short old;
+       unsigned long flags;
+
+       sc = lookup_swap_cgroup(ent, &ctrl);
+
+       spin_lock_irqsave(&ctrl->lock, flags);
+       old = sc->id;
+       sc->id = id;
+       spin_unlock_irqrestore(&ctrl->lock, flags);
+
+       return old;
+}
+
+/**
+ * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry
+ * @ent: swap entry to be looked up.
+ *
+ * Returns ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
+ */
+unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
+{
+       return lookup_swap_cgroup(ent, NULL)->id;
+}
+
+int swap_cgroup_swapon(int type, unsigned long max_pages)
+{
+       void *array;
+       unsigned long array_size;
+       unsigned long length;
+       struct swap_cgroup_ctrl *ctrl;
+
+       if (!do_swap_account)
+               return 0;
+
+       length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
+       array_size = length * sizeof(void *);
+
+       array = vzalloc(array_size);
+       if (!array)
+               goto nomem;
+
+       ctrl = &swap_cgroup_ctrl[type];
+       mutex_lock(&swap_cgroup_mutex);
+       ctrl->length = length;
+       ctrl->map = array;
+       spin_lock_init(&ctrl->lock);
+       if (swap_cgroup_prepare(type)) {
+               /* memory shortage */
+               ctrl->map = NULL;
+               ctrl->length = 0;
+               mutex_unlock(&swap_cgroup_mutex);
+               vfree(array);
+               goto nomem;
+       }
+       mutex_unlock(&swap_cgroup_mutex);
+
+       return 0;
+nomem:
+       printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
+       printk(KERN_INFO
+               "swap_cgroup can be disabled by swapaccount=0 boot option\n");
+       return -ENOMEM;
+}
+
+void swap_cgroup_swapoff(int type)
+{
+       struct page **map;
+       unsigned long i, length;
+       struct swap_cgroup_ctrl *ctrl;
+
+       if (!do_swap_account)
+               return;
+
+       mutex_lock(&swap_cgroup_mutex);
+       ctrl = &swap_cgroup_ctrl[type];
+       map = ctrl->map;
+       length = ctrl->length;
+       ctrl->map = NULL;
+       ctrl->length = 0;
+       mutex_unlock(&swap_cgroup_mutex);
+
+       if (map) {
+               for (i = 0; i < length; i++) {
+                       struct page *page = map[i];
+                       if (page)
+                               __free_page(page);
+               }
+               vfree(map);
+       }
+}
index 1544449..9711342 100644 (file)
@@ -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>
 
index 8798b2e..63f55cc 100644 (file)
@@ -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);