[PATCH -V8 13/16] hugetlb/cgroup: add hugetlb cgroup control files

From: Aneesh Kumar K.V
Date: Sat Jun 09 2012 - 05:01:47 EST


From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>

Add the control files for hugetlb controller

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 5 ++
include/linux/hugetlb_cgroup.h | 6 ++
mm/hugetlb.c | 8 +++
mm/hugetlb_cgroup.c | 130 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 149 insertions(+)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 4aca057..9650bb1 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -4,6 +4,7 @@
#include <linux/mm_types.h>
#include <linux/fs.h>
#include <linux/hugetlb_inline.h>
+#include <linux/cgroup.h>

struct ctl_table;
struct user_struct;
@@ -221,6 +222,10 @@ struct hstate {
unsigned int nr_huge_pages_node[MAX_NUMNODES];
unsigned int free_huge_pages_node[MAX_NUMNODES];
unsigned int surplus_huge_pages_node[MAX_NUMNODES];
+#ifdef CONFIG_CGROUP_HUGETLB_RES_CTLR
+ /* cgroup control files */
+ struct cftype cgroup_files[5];
+#endif
char name[HSTATE_NAME_LEN];
};

diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index ceff1d5..ba4836f 100644
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -62,6 +62,7 @@ extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
struct page *page);
extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg);
+extern int hugetlb_cgroup_file_init(int idx) __init;
#else
static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
{
@@ -106,5 +107,10 @@ hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
{
return;
}
+
+static inline int __init hugetlb_cgroup_file_init(int idx)
+{
+ return 0;
+}
#endif /* CONFIG_MEM_RES_CTLR_HUGETLB */
#endif
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1ca2d8f..bf79131 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -30,6 +30,7 @@
#include <linux/hugetlb.h>
#include <linux/hugetlb_cgroup.h>
#include <linux/node.h>
+#include <linux/hugetlb_cgroup.h>
#include "internal.h"

const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
@@ -1916,6 +1917,13 @@ void __init hugetlb_add_hstate(unsigned order)
h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]);
snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
huge_page_size(h)/1024);
+ /*
+ * Add cgroup control files only if the huge page consists
+ * of more than two normal pages. This is because we use
+ * page[2].lru.next for storing cgoup details.
+ */
+ if (order >= 2)
+ hugetlb_cgroup_file_init(hugetlb_max_hstate - 1);

parsed_hstate = h;
}
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 9458fe3..2a4881d 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -18,6 +18,11 @@
#include <linux/hugetlb.h>
#include <linux/hugetlb_cgroup.h>

+/* lifted from mem control */
+#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
+#define MEMFILE_IDX(val) (((val) >> 16) & 0xffff)
+#define MEMFILE_ATTR(val) ((val) & 0xffff)
+
struct cgroup_subsys hugetlb_subsys __read_mostly;
struct hugetlb_cgroup *root_h_cgroup __read_mostly;

@@ -269,6 +274,131 @@ void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
return;
}

+static ssize_t hugetlb_cgroup_read(struct cgroup *cgroup, struct cftype *cft,
+ struct file *file, char __user *buf,
+ size_t nbytes, loff_t *ppos)
+{
+ u64 val;
+ char str[64];
+ int idx, name, len;
+ struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
+
+ 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);
+}
+
+static int hugetlb_cgroup_write(struct cgroup *cgroup, struct cftype *cft,
+ const char *buffer)
+{
+ int idx, name, ret;
+ unsigned long long val;
+ struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
+
+ idx = MEMFILE_IDX(cft->private);
+ name = MEMFILE_ATTR(cft->private);
+
+ switch (name) {
+ case RES_LIMIT:
+ if (hugetlb_cgroup_is_root(h_cg)) {
+ /* Can't set limit on root */
+ ret = -EINVAL;
+ break;
+ }
+ /* This function does all necessary parse...reuse it */
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (ret)
+ break;
+ ret = res_counter_set_limit(&h_cg->hugepage[idx], val);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ return ret;
+}
+
+static int hugetlb_cgroup_reset(struct cgroup *cgroup, unsigned int event)
+{
+ int idx, name, ret = 0;
+ struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
+
+ idx = MEMFILE_IDX(event);
+ name = MEMFILE_ATTR(event);
+
+ switch (name) {
+ case RES_MAX_USAGE:
+ res_counter_reset_max(&h_cg->hugepage[idx]);
+ break;
+ case RES_FAILCNT:
+ res_counter_reset_failcnt(&h_cg->hugepage[idx]);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ return ret;
+}
+
+static char *mem_fmt(char *buf, int size, unsigned long hsize)
+{
+ if (hsize >= (1UL << 30))
+ snprintf(buf, size, "%luGB", hsize >> 30);
+ else if (hsize >= (1UL << 20))
+ snprintf(buf, size, "%luMB", hsize >> 20);
+ else
+ snprintf(buf, size, "%luKB", hsize >> 10);
+ return buf;
+}
+
+int __init hugetlb_cgroup_file_init(int idx)
+{
+ char buf[32];
+ struct cftype *cft;
+ struct hstate *h = &hstates[idx];
+
+ /* format the size */
+ mem_fmt(buf, 32, huge_page_size(h));
+
+ /* Add the limit file */
+ 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->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;
+
+ /* 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;
+
+ /* 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;
+
+ /* NULL terminate the last cft */
+ cft = &h->cgroup_files[4];
+ memset(cft, 0, sizeof(*cft));
+
+ WARN_ON(cgroup_add_cftypes(&hugetlb_subsys, h->cgroup_files));
+
+ return 0;
+}
+
struct cgroup_subsys hugetlb_subsys = {
.name = "hugetlb",
.create = hugetlb_cgroup_create,
--
1.7.10

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