memcg: allocate all page_cgroup at boot

Allocate all page_cgroup at boot and remove page_cgroup poitner from
struct page.  This patch adds an interface as

 struct page_cgroup *lookup_page_cgroup(struct page*)

All FLATMEM/DISCONTIGMEM/SPARSEMEM  and MEMORY_HOTPLUG is supported.

Remove page_cgroup pointer reduces the amount of memory by
 - 4 bytes per PAGE_SIZE.
 - 8 bytes per PAGE_SIZE
if memory controller is disabled. (even if configured.)

On usual 8GB x86-32 server, this saves 8MB of NORMAL_ZONE memory.
On my x86-64 server with 48GB of memory, this saves 96MB of memory.
I think this reduction makes sense.

By pre-allocation, kmalloc/kfree in charge/uncharge are removed.
This means
  - we're not necessary to be afraid of kmalloc faiulre.
    (this can happen because of gfp_mask type.)
  - we can avoid calling kmalloc/kfree.
  - we can avoid allocating tons of small objects which can be fragmented.
  - we can know what amount of memory will be used for this extra-lru handling.

I added printk message as

	"allocated %ld bytes of page_cgroup"
        "please try cgroup_disable=memory option if you don't want"

maybe enough informative for users.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KAMEZAWA Hiroyuki 2008-10-18 20:28:16 -07:00 committed by Linus Torvalds
parent c05555b572
commit 52d4b9ac0b
8 changed files with 438 additions and 194 deletions

View file

@ -27,9 +27,6 @@ struct mm_struct;
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
#define page_reset_bad_cgroup(page) ((page)->page_cgroup = 0)
extern struct page_cgroup *page_get_page_cgroup(struct page *page);
extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask);
extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
@ -72,16 +69,8 @@ extern void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem,
extern long mem_cgroup_calc_reclaim(struct mem_cgroup *mem, struct zone *zone,
int priority, enum lru_list lru);
#else /* CONFIG_CGROUP_MEM_RES_CTLR */
static inline void page_reset_bad_cgroup(struct page *page)
{
}
static inline struct page_cgroup *page_get_page_cgroup(struct page *page)
{
return NULL;
}
static inline int mem_cgroup_charge(struct page *page,
struct mm_struct *mm, gfp_t gfp_mask)
{