memory cgroup enhancements: remember "a page is charged as page cache"
Add a flag to page_cgroup to remember "this page is
charged as cache."
cache here includes page caches and swap cache.
This is useful for implementing precise accounting in memory cgroup.
TODO:
distinguish page-cache and swap-cache
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c867612..975e899 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -83,7 +83,9 @@
struct mem_cgroup *mem_cgroup;
atomic_t ref_cnt; /* Helpful when pages move b/w */
/* mapped and cached states */
+ int flags;
};
+#define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */
enum {
MEM_CGROUP_TYPE_UNSPEC = 0,
@@ -93,6 +95,11 @@
MEM_CGROUP_TYPE_MAX,
};
+enum charge_type {
+ MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED,
+};
+
static struct mem_cgroup init_mem_cgroup;
static inline
@@ -306,8 +313,8 @@
* 0 if the charge was successful
* < 0 if the cgroup is over its limit
*/
-int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
- gfp_t gfp_mask)
+static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask, enum charge_type ctype)
{
struct mem_cgroup *mem;
struct page_cgroup *pc;
@@ -409,6 +416,9 @@
atomic_set(&pc->ref_cnt, 1);
pc->mem_cgroup = mem;
pc->page = page;
+ pc->flags = 0;
+ if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
+ pc->flags |= PAGE_CGROUP_FLAG_CACHE;
if (page_cgroup_assign_new_page_cgroup(page, pc)) {
/*
* an another charge is added to this page already.
@@ -433,6 +443,13 @@
return -ENOMEM;
}
+int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask)
+{
+ return mem_cgroup_charge_common(page, mm, gfp_mask,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED);
+}
+
/*
* See if the cached pages should be charged at all?
*/
@@ -445,7 +462,8 @@
mem = rcu_dereference(mm->mem_cgroup);
if (mem->control_type == MEM_CGROUP_TYPE_ALL)
- return mem_cgroup_charge(page, mm, gfp_mask);
+ return mem_cgroup_charge_common(page, mm, gfp_mask,
+ MEM_CGROUP_CHARGE_TYPE_CACHE);
else
return 0;
}