[PATCH v3 09/11] memcg: add cgroupfs interface to memcg dirty limits

Greg Thelen
2010-10-19T00:44:31Z

Add cgroupfs interface to memcg dirty page limits:
Direct write-out is controlled with:
- memory.dirty_ratio
- memory.dirty_limit_in_bytes

Background write-out is controlled with:
- memory.dirty_background_ratio
- memory.dirty_background_limit_bytes

Other memcg cgroupfs files support 'M', 'm', 'k', 'K', 'g'
and 'G' suffixes for byte counts. This patch provides the
same functionality for memory.dirty_limit_in_bytes and
memory.dirty_background_limit_bytes.

Signed-off-by: Andrea Righi <arighi@develer.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
---

Changelog since v1:
- Renamed newly created proc files:
- memory.dirty_bytes -> memory.dirty_limit_in_bytes
- memory.dirty_background_bytes -> memory.dirty_background_limit_in_bytes
- Allow [kKmMgG] suffixes for newly created dirty limit value cgroupfs files.

mm/memcontrol.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 116 insertions(+), 0 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 412ce73..580e665 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -100,6 +100,13 @@ enum mem_cgroup_stat_index {
MEM_CGROUP_STAT_NSTATS,
};

+enum {
+ MEM_CGROUP_DIRTY_RATIO,
+ MEM_CGROUP_DIRTY_LIMIT_IN_BYTES,
+ MEM_CGROUP_DIRTY_BACKGROUND_RATIO,
+ MEM_CGROUP_DIRTY_BACKGROUND_LIMIT_IN_BYTES,
+};
+
struct mem_cgroup_stat_cpu {
s64 count[MEM_CGROUP_STAT_NSTATS];
};
@@ -4311,6 +4318,91 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
return 0;
}

+static u64 mem_cgroup_dirty_read(struct cgroup *cgrp, struct cftype *cft)
+{
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+ bool root;
+
+ root = mem_cgroup_is_root(mem);
+
+ switch (cft->private) {
+ case MEM_CGROUP_DIRTY_RATIO:
+ return root ? vm_dirty_ratio : mem->dirty_param.dirty_ratio;
+ case MEM_CGROUP_DIRTY_LIMIT_IN_BYTES:
+ return root ? vm_dirty_bytes : mem->dirty_param.dirty_bytes;
+ case MEM_CGROUP_DIRTY_BACKGROUND_RATIO:
+ return root ? dirty_background_ratio :
+ mem->dirty_param.dirty_background_ratio;
+ case MEM_CGROUP_DIRTY_BACKGROUND_LIMIT_IN_BYTES:
+ return root ? dirty_background_bytes :
+ mem->dirty_param.dirty_background_bytes;
+ default:
+ BUG();
+ }
+}
+
+static int
+mem_cgroup_dirty_write_string(struct cgroup *cgrp, struct cftype *cft,
+ const char *buffer)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ int type = cft->private;
+ int ret = -EINVAL;
+ unsigned long long val;
+
+ if (cgrp->parent == NULL)
+ return ret;
+
+ switch (type) {
+ case MEM_CGROUP_DIRTY_LIMIT_IN_BYTES:
+ /* This function does all necessary parse...reuse it */
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (ret)
+ break;
+ memcg->dirty_param.dirty_bytes = val;
+ memcg->dirty_param.dirty_ratio = 0;
+ break;
+ case MEM_CGROUP_DIRTY_BACKGROUND_LIMIT_IN_BYTES:
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (ret)
+ break;
+ memcg->dirty_param.dirty_background_bytes = val;
+ memcg->dirty_param.dirty_background_ratio = 0;
+ break;
+ default:
+ BUG();
+ break;
+ }
+ return ret;
+}
+
+static int
+mem_cgroup_dirty_write(struct cgroup *cgrp, struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ int type = cft->private;
+
+ if (cgrp->parent == NULL)
+ return -EINVAL;
+ if ((type == MEM_CGROUP_DIRTY_RATIO ||
+ type == MEM_CGROUP_DIRTY_BACKGROUND_RATIO) && val > 100)
+ return -EINVAL;
+ switch (type) {
+ case MEM_CGROUP_DIRTY_RATIO:
+ memcg->dirty_param.dirty_ratio = val;
+ memcg->dirty_param.dirty_bytes = 0;
+ break;
+ case MEM_CGROUP_DIRTY_BACKGROUND_RATIO:
+ memcg->dirty_param.dirty_background_ratio = val;
+ memcg->dirty_param.dirty_background_bytes = 0;
+ break;
+ default:
+ BUG();
+ break;
+ }
+ return 0;
+}
+
static struct cftype mem_cgroup_files[] = {
{
.name = "usage_in_bytes",
@@ -4374,6 +4466,30 @@ static struct cftype mem_cgroup_files[] = {
.unregister_event = mem_cgroup_oom_unregister_event,
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
},
+ {
+ .name = "dirty_ratio",
+ .read_u64 = mem_cgroup_dirty_read,
+ .write_u64 = mem_cgroup_dirty_write,
+ .private = MEM_CGROUP_DIRTY_RATIO,
+ },
+ {
+ .name = "dirty_limit_in_bytes",
+ .read_u64 = mem_cgroup_dirty_read,
+ .write_string = mem_cgroup_dirty_write_string,
+ .private = MEM_CGROUP_DIRTY_LIMIT_IN_BYTES,
+ },
+ {
+ .name = "dirty_background_ratio",
+ .read_u64 = mem_cgroup_dirty_read,
+ .write_u64 = mem_cgroup_dirty_write,
+ .private = MEM_CGROUP_DIRTY_BACKGROUND_RATIO,
+ },
+ {
+ .name = "dirty_background_limit_in_bytes",
+ .read_u64 = mem_cgroup_dirty_read,
+ .write_string = mem_cgroup_dirty_write_string,
+ .private = MEM_CGROUP_DIRTY_BACKGROUND_LIMIT_IN_BYTES,
+ },
};

#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
--
1.7.1