Memory controller: add switch to control what type of pages to limit
Choose if we want cached pages to be accounted or not. By default both are
accounted for. A new set of tunables are added.
echo -n 1 > mem_control_type
switches the accounting to account for only mapped pages
echo -n 3 > mem_control_type
switches the behaviour back
[bunk@kernel.org: mm/memcontrol.c: clenups]
[akpm@linux-foundation.org: fix sparc32 build]
Signed-off-by: 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: Adrian Bunk <bunk@kernel.org>
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 5260658..10833d9 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -29,6 +29,8 @@
#include <linux/spinlock.h>
#include <linux/fs.h>
+#include <asm/uaccess.h>
+
struct cgroup_subsys mem_cgroup_subsys;
static const int MEM_CGROUP_RECLAIM_RETRIES = 5;
@@ -60,6 +62,7 @@
* spin_lock to protect the per cgroup LRU
*/
spinlock_t lru_lock;
+ unsigned long control_type; /* control RSS or RSS+Pagecache */
};
/*
@@ -82,6 +85,15 @@
/* mapped and cached states */
};
+enum {
+ MEM_CGROUP_TYPE_UNSPEC = 0,
+ MEM_CGROUP_TYPE_MAPPED,
+ MEM_CGROUP_TYPE_CACHED,
+ MEM_CGROUP_TYPE_ALL,
+ MEM_CGROUP_TYPE_MAX,
+};
+
+static struct mem_cgroup init_mem_cgroup;
static inline
struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
@@ -139,18 +151,18 @@
(page->page_cgroup & ~PAGE_CGROUP_LOCK);
}
-void __always_inline lock_page_cgroup(struct page *page)
+static void __always_inline lock_page_cgroup(struct page *page)
{
bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
VM_BUG_ON(!page_cgroup_locked(page));
}
-void __always_inline unlock_page_cgroup(struct page *page)
+static void __always_inline unlock_page_cgroup(struct page *page)
{
bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
}
-void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
+static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
{
if (active)
list_move(&pc->lru, &pc->mem_cgroup->active_list);
@@ -366,6 +378,22 @@
}
/*
+ * See if the cached pages should be charged at all?
+ */
+int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm)
+{
+ struct mem_cgroup *mem;
+ if (!mm)
+ mm = &init_mm;
+
+ mem = rcu_dereference(mm->mem_cgroup);
+ if (mem->control_type == MEM_CGROUP_TYPE_ALL)
+ return mem_cgroup_charge(page, mm);
+ else
+ return 0;
+}
+
+/*
* Uncharging is always a welcome operation, we never complain, simply
* uncharge.
*/
@@ -375,6 +403,10 @@
struct page *page;
unsigned long flags;
+ /*
+ * This can handle cases when a page is not charged at all and we
+ * are switching between handling the control_type.
+ */
if (!pc)
return;
@@ -425,6 +457,60 @@
mem_cgroup_write_strategy);
}
+static ssize_t mem_control_type_write(struct cgroup *cont,
+ struct cftype *cft, struct file *file,
+ const char __user *userbuf,
+ size_t nbytes, loff_t *pos)
+{
+ int ret;
+ char *buf, *end;
+ unsigned long tmp;
+ struct mem_cgroup *mem;
+
+ mem = mem_cgroup_from_cont(cont);
+ buf = kmalloc(nbytes + 1, GFP_KERNEL);
+ ret = -ENOMEM;
+ if (buf == NULL)
+ goto out;
+
+ buf[nbytes] = 0;
+ ret = -EFAULT;
+ if (copy_from_user(buf, userbuf, nbytes))
+ goto out_free;
+
+ ret = -EINVAL;
+ tmp = simple_strtoul(buf, &end, 10);
+ if (*end != '\0')
+ goto out_free;
+
+ if (tmp <= MEM_CGROUP_TYPE_UNSPEC || tmp >= MEM_CGROUP_TYPE_MAX)
+ goto out_free;
+
+ mem->control_type = tmp;
+ ret = nbytes;
+out_free:
+ kfree(buf);
+out:
+ return ret;
+}
+
+static ssize_t mem_control_type_read(struct cgroup *cont,
+ struct cftype *cft,
+ struct file *file, char __user *userbuf,
+ size_t nbytes, loff_t *ppos)
+{
+ unsigned long val;
+ char buf[64], *s;
+ struct mem_cgroup *mem;
+
+ mem = mem_cgroup_from_cont(cont);
+ s = buf;
+ val = mem->control_type;
+ s += sprintf(s, "%lu\n", val);
+ return simple_read_from_buffer((void __user *)userbuf, nbytes,
+ ppos, buf, s - buf);
+}
+
static struct cftype mem_cgroup_files[] = {
{
.name = "usage_in_bytes",
@@ -442,6 +528,11 @@
.private = RES_FAILCNT,
.read = mem_cgroup_read,
},
+ {
+ .name = "control_type",
+ .write = mem_control_type_write,
+ .read = mem_control_type_read,
+ },
};
static struct mem_cgroup init_mem_cgroup;
@@ -464,6 +555,7 @@
INIT_LIST_HEAD(&mem->active_list);
INIT_LIST_HEAD(&mem->inactive_list);
spin_lock_init(&mem->lru_lock);
+ mem->control_type = MEM_CGROUP_TYPE_ALL;
return &mem->css;
}