hugetlb_cgroup: convert away from cftype->read()

In preparation of conversion to kernfs, cgroup file handling is being
consolidated so that it can be easily mapped to the seq_file based
interface of kernfs.

All users of cftype->read() can be easily served, usually better, by
seq_file and other methods.  Update hugetlb_cgroup_read() to return
u64 instead of printing itself and rename it to
hugetlb_cgroup_read_u64().

This patch doesn't make any visible behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
This commit is contained in:
Tejun Heo 2013-12-05 12:28:03 -05:00
parent e92e113cab
commit 716f479d27

View File

@ -242,22 +242,16 @@ void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
return;
}
static ssize_t hugetlb_cgroup_read(struct cgroup_subsys_state *css,
struct cftype *cft, struct file *file,
char __user *buf, size_t nbytes,
loff_t *ppos)
static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
u64 val;
char str[64];
int idx, name, len;
int idx, name;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
idx = MEMFILE_IDX(cft->private);
name = MEMFILE_ATTR(cft->private);
val = res_counter_read_u64(&h_cg->hugepage[idx], name);
len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
return simple_read_from_buffer(buf, nbytes, ppos, str, len);
return res_counter_read_u64(&h_cg->hugepage[idx], name);
}
static int hugetlb_cgroup_write(struct cgroup_subsys_state *css,
@ -337,28 +331,28 @@ static void __init __hugetlb_cgroup_file_init(int idx)
cft = &h->cgroup_files[0];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
cft->read = hugetlb_cgroup_read;
cft->read_u64 = hugetlb_cgroup_read_u64;
cft->write_string = hugetlb_cgroup_write;
/* Add the usage file */
cft = &h->cgroup_files[1];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
cft->read = hugetlb_cgroup_read;
cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the MAX usage file */
cft = &h->cgroup_files[2];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE);
cft->trigger = hugetlb_cgroup_reset;
cft->read = hugetlb_cgroup_read;
cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the failcntfile */
cft = &h->cgroup_files[3];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT);
cft->trigger = hugetlb_cgroup_reset;
cft->read = hugetlb_cgroup_read;
cft->read_u64 = hugetlb_cgroup_read_u64;
/* NULL terminate the last cft */
cft = &h->cgroup_files[4];