[RFC 2/7] mm: introduce alloc_bps to memcg for memory allocation speed throttle

[yulei.kernel@xxxxxxxxx]

From: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>

Add read/write attribute memory.alloc_bps to configure the allowable
memory allocation speed of the memory cgroup in bytes.

Signed-off-by: Jiang Biao <benbjiang@xxxxxxxxxxx>
Signed-off-by: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>
---
 include/linux/memcontrol.h | 10 ++++++++++
 mm/memcontrol.c            | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index c193be760709..4938397f321d 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -230,6 +230,12 @@ struct obj_cgroup {
 	};
 };
 
+#ifdef CONFIG_MEM_SPEED_THROTTLE
+struct mem_spd_ctl {
+	unsigned long mem_spd_lmt;
+};
+#endif
+
 /*
  * The memory controller data structure. The memory controller controls both
  * page cache and RSS per cgroup. We would eventually like to provide
@@ -349,6 +355,10 @@ struct mem_cgroup {
 	struct deferred_split deferred_split_queue;
 #endif
 
+#ifdef CONFIG_MEM_SPEED_THROTTLE
+	struct mem_spd_ctl msc;
+#endif
+
 	struct mem_cgroup_per_node *nodeinfo[0];
 	/* WARNING: nodeinfo must be the last member here */
 };
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7ef6aa088680..d59abe15d89d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1393,6 +1393,28 @@ static int memcg_page_state_unit(int item)
 }
 
 #ifdef CONFIG_MEM_SPEED_THROTTLE
+static u64 mem_cgroup_mem_spd_lmt_read(struct cgroup_subsys_state *css,
+				       struct cftype *cft)
+{
+	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+	return (u64)(memcg->msc.mem_spd_lmt << PAGE_SHIFT);
+}
+
+static int mem_cgroup_mem_spd_lmt_write(struct cgroup_subsys_state *css,
+					struct cftype *cft, u64 val)
+{
+	struct mem_cgroup *memcg;
+	unsigned long lmt;
+
+	memcg = mem_cgroup_from_css(css);
+	lmt = val >> PAGE_SHIFT;
+
+	memcg->msc.mem_spd_lmt = lmt;
+
+	return 0;
+}
+
 static unsigned long mem_cgroup_mst_get_mem_spd_max(struct mem_cgroup *memcg)
 {
 	struct page_counter *c = &memcg->memory;
@@ -4805,6 +4827,14 @@ static struct cftype mem_cgroup_legacy_files[] = {
 		.write_u64 = mem_cgroup_hierarchy_write,
 		.read_u64 = mem_cgroup_hierarchy_read,
 	},
+#ifdef CONFIG_MEM_SPEED_THROTTLE
+	{
+		.name = "alloc_bps",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.read_u64 = mem_cgroup_mem_spd_lmt_read,
+		.write_u64 = mem_cgroup_mem_spd_lmt_write,
+	},
+#endif
 	{
 		.name = "cgroup.event_control",		/* XXX: for compat */
 		.write = memcg_write_event_control,
@@ -6358,6 +6388,14 @@ static struct cftype memory_files[] = {
 		.seq_show = memory_oom_group_show,
 		.write = memory_oom_group_write,
 	},
+#ifdef CONFIG_MEM_SPEED_THROTTLE
+	{
+		.name = "alloc_bps",
+		.write_u64 = mem_cgroup_mem_spd_lmt_write,
+		.read_u64 = mem_cgroup_mem_spd_lmt_read,
+		.flags = CFTYPE_NOT_ON_ROOT,
+	},
+#endif
 	{ }	/* terminate */
 };
 
-- 
2.28.0