cpuset: add cpuset1_init helper for v1 initialization

This patch introduces the cpuset1_init helper in cpuset_v1.c to initialize
v1-specific fields, including the fmeter and relax_domain_level members.

The relax_domain_level related code will be moved to cpuset_v1.c in a
subsequent patch. After this move, v1-specific members will only be
visible when CONFIG_CPUSETS_V1=y.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: Chen Ridong

kernel/cgroup/cpuset-internal.h

@@ -144,8 +144,6 @@ struct cpuset {
 	 */
 	nodemask_t old_mems_allowed;
 
-	struct fmeter fmeter;		/* memory_pressure filter */
-
 	/*
 	 * Tasks are being attached to this cpuset.  Used to prevent
 	 * zeroing cpus/mems_allowed between ->can_attach() and ->attach().
@@ -181,6 +179,10 @@ struct cpuset {
 
 	/* Used to merge intersecting subsets for generate_sched_domains */
 	struct uf_node node;
+
+#ifdef CONFIG_CPUSETS_V1
+	struct fmeter fmeter;		/* memory_pressure filter */
+#endif
 };
 
 static inline struct cpuset *css_cs(struct cgroup_subsys_state *css)
@@ -285,17 +287,16 @@ void cpuset_full_unlock(void);
  */
 #ifdef CONFIG_CPUSETS_V1
 extern struct cftype cpuset1_files[];
-void fmeter_init(struct fmeter *fmp);
 void cpuset1_update_task_spread_flags(struct cpuset *cs,
 					struct task_struct *tsk);
 void cpuset1_update_tasks_flags(struct cpuset *cs);
 void cpuset1_hotplug_update_tasks(struct cpuset *cs,
 			    struct cpumask *new_cpus, nodemask_t *new_mems,
 			    bool cpus_updated, bool mems_updated);
 int cpuset1_validate_change(struct cpuset *cur, struct cpuset *trial);
+void cpuset1_init(struct cpuset *cs);
 void cpuset1_online_css(struct cgroup_subsys_state *css);
 #else
-static inline void fmeter_init(struct fmeter *fmp) {}
 static inline void cpuset1_update_task_spread_flags(struct cpuset *cs,
 					struct task_struct *tsk) {}
 static inline void cpuset1_update_tasks_flags(struct cpuset *cs) {}
@@ -304,6 +305,7 @@ static inline void cpuset1_hotplug_update_tasks(struct cpuset *cs,
 			    bool cpus_updated, bool mems_updated) {}
 static inline int cpuset1_validate_change(struct cpuset *cur,
 				struct cpuset *trial) { return 0; }
+static inline void cpuset1_init(struct cpuset *cs) {}
 static inline void cpuset1_online_css(struct cgroup_subsys_state *css) {}
 #endif /* CONFIG_CPUSETS_V1 */
 

kernel/cgroup/cpuset-v1.c

@@ -62,7 +62,7 @@ struct cpuset_remove_tasks_struct {
 #define FM_SCALE 1000		/* faux fixed point scale */
 
 /* Initialize a frequency meter */
-void fmeter_init(struct fmeter *fmp)
+static void fmeter_init(struct fmeter *fmp)
 {
 	fmp->cnt = 0;
 	fmp->val = 0;
@@ -499,6 +499,11 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 	return retval;
 }
 
+void cpuset1_init(struct cpuset *cs)
+{
+	fmeter_init(&cs->fmeter);
+}
+
 void cpuset1_online_css(struct cgroup_subsys_state *css)
 {
 	struct cpuset *tmp_cs;

kernel/cgroup/cpuset.c

@@ -3602,7 +3602,7 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
 		return ERR_PTR(-ENOMEM);
 
 	__set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
-	fmeter_init(&cs->fmeter);
+	cpuset1_init(cs);
 	cs->relax_domain_level = -1;
 
 	/* Set CS_MEMORY_MIGRATE for default hierarchy */
@@ -3836,7 +3836,7 @@ int __init cpuset_init(void)
 	cpumask_setall(top_cpuset.exclusive_cpus);
 	nodes_setall(top_cpuset.effective_mems);
 
-	fmeter_init(&top_cpuset.fmeter);
+	cpuset1_init(&top_cpuset);
 
 	BUG_ON(!alloc_cpumask_var(&cpus_attach, GFP_KERNEL));