diff options
author | Johannes Weiner <hannes@cmpxchg.org> | 2014-12-10 15:44:55 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-10 17:41:09 -0800 |
commit | 5d1ea48bdde67898e87d6d8f511fd097fa64c749 (patch) | |
tree | 2936b8ed4b948ffdf655fd7b8fa71d68069f8bc4 /mm/page_cgroup.c | |
parent | 1306a85aed3ec3db98945aafb7dfbe5648a1203c (diff) | |
download | op-kernel-dev-5d1ea48bdde67898e87d6d8f511fd097fa64c749.zip op-kernel-dev-5d1ea48bdde67898e87d6d8f511fd097fa64c749.tar.gz |
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>
Diffstat (limited to 'mm/page_cgroup.c')
-rw-r--r-- | mm/page_cgroup.c | 211 |
1 files changed, 0 insertions, 211 deletions
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c deleted file mode 100644 index f0f31c1..0000000 --- a/mm/page_cgroup.c +++ /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 |