memcg: always create memsw files if CONFIG_CGROUP_MEM_RES_CTLR_SWAP

Instead of conditioning creation of memsw files on do_swap_account,
always create the files if compiled-in and fail read/write attempts
with -EOPNOTSUPP if !do_swap_account.

This is suggested by KAMEZAWA to simplify memcg file creation so that
it can use cgroup->subsys_cftypes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
This commit is contained in:
Tejun Heo 2012-04-01 12:09:55 -07:00
parent 4baf6e3325
commit af36f906c0

View File

@ -3879,14 +3879,21 @@ static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
return val << PAGE_SHIFT;
}
static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
char str[64];
u64 val;
int type, name;
int type, name, len;
type = MEMFILE_TYPE(cft->private);
name = MEMFILE_ATTR(cft->private);
if (!do_swap_account && type == _MEMSWAP)
return -EOPNOTSUPP;
switch (type) {
case _MEM:
if (name == RES_USAGE)
@ -3903,7 +3910,9 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
default:
BUG();
}
return val;
len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
return simple_read_from_buffer(buf, nbytes, ppos, str, len);
}
/*
* The user of this function is...
@ -3919,6 +3928,10 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
type = MEMFILE_TYPE(cft->private);
name = MEMFILE_ATTR(cft->private);
if (!do_swap_account && type == _MEMSWAP)
return -EOPNOTSUPP;
switch (name) {
case RES_LIMIT:
if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
@ -3984,12 +3997,15 @@ out:
static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
{
struct mem_cgroup *memcg;
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
int type, name;
memcg = mem_cgroup_from_cont(cont);
type = MEMFILE_TYPE(event);
name = MEMFILE_ATTR(event);
if (!do_swap_account && type == _MEMSWAP)
return -EOPNOTSUPP;
switch (name) {
case RES_MAX_USAGE:
if (type == _MEM)
@ -4655,7 +4671,7 @@ static struct cftype mem_cgroup_files[] = {
{
.name = "usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
.register_event = mem_cgroup_usage_register_event,
.unregister_event = mem_cgroup_usage_unregister_event,
},
@ -4663,25 +4679,25 @@ static struct cftype mem_cgroup_files[] = {
.name = "max_usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
.trigger = mem_cgroup_reset,
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
},
{
.name = "limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
.write_string = mem_cgroup_write,
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
},
{
.name = "soft_limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
.write_string = mem_cgroup_write,
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
},
{
.name = "failcnt",
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
.trigger = mem_cgroup_reset,
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
},
{
.name = "stat",
@ -4721,14 +4737,11 @@ static struct cftype mem_cgroup_files[] = {
.mode = S_IRUGO,
},
#endif
};
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
static struct cftype memsw_cgroup_files[] = {
{
.name = "memsw.usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
.register_event = mem_cgroup_usage_register_event,
.unregister_event = mem_cgroup_usage_unregister_event,
},
@ -4736,35 +4749,22 @@ static struct cftype memsw_cgroup_files[] = {
.name = "memsw.max_usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
.trigger = mem_cgroup_reset,
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
},
{
.name = "memsw.limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
.write_string = mem_cgroup_write,
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
},
{
.name = "memsw.failcnt",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
.trigger = mem_cgroup_reset,
.read_u64 = mem_cgroup_read,
.read = mem_cgroup_read,
},
};
static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
{
if (!do_swap_account)
return 0;
return cgroup_add_files(cont, ss, memsw_cgroup_files,
ARRAY_SIZE(memsw_cgroup_files));
};
#else
static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
{
return 0;
}
#endif
};
static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
{
@ -5046,9 +5046,6 @@ static int mem_cgroup_populate(struct cgroup_subsys *ss,
ret = cgroup_add_files(cont, ss, mem_cgroup_files,
ARRAY_SIZE(mem_cgroup_files));
if (!ret)
ret = register_memsw_files(cont, ss);
if (!ret)
ret = register_kmem_files(cont, ss);