cgroup/cpuset: move relax_domain_level to cpuset-v1.c

Setting domain level is not supported at cpuset v2, so move corresponding
code into cpuset-v1.c.

The 'cpuset_write_s64' and 'cpuset_read_s64' are only used for setting
domain level, move them to cpuset-v1.c. Currently, expose to cpuset.c.
After cpuset legacy interface files are move to cpuset-v1.c, they can
be static. The 'rebuild_sched_domains_locked' is exposed to cpuset-v1.c.

The change from original code is that using 'cpuset_lock' and
'cpuset_unlock' functions to lock or unlock cpuset_mutex.

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

kernel/cgroup/cpuset-internal.h

@@ -238,11 +238,15 @@ static inline int is_spread_slab(const struct cpuset *cs)
 	return test_bit(CS_SPREAD_SLAB, &cs->flags);
 }
 
+void rebuild_sched_domains_locked(void);
+
 /*
  * cpuset-v1.c
  */
-
 void fmeter_init(struct fmeter *fmp);
 int fmeter_getrate(struct fmeter *fmp);
+int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
+			    s64 val);
+s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft);
 
 #endif /* __CPUSET_INTERNAL_H */

kernel/cgroup/cpuset-v1.c

@@ -135,3 +135,62 @@ void __cpuset_memory_pressure_bump(void)
 	fmeter_markevent(&task_cs(current)->fmeter);
 	rcu_read_unlock();
 }
+
+static int update_relax_domain_level(struct cpuset *cs, s64 val)
+{
+#ifdef CONFIG_SMP
+	if (val < -1 || val > sched_domain_level_max + 1)
+		return -EINVAL;
+#endif
+
+	if (val != cs->relax_domain_level) {
+		cs->relax_domain_level = val;
+		if (!cpumask_empty(cs->cpus_allowed) &&
+		    is_sched_load_balance(cs))
+			rebuild_sched_domains_locked();
+	}
+
+	return 0;
+}
+
+int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
+			    s64 val)
+{
+	struct cpuset *cs = css_cs(css);
+	cpuset_filetype_t type = cft->private;
+	int retval = -ENODEV;
+
+	cpus_read_lock();
+	cpuset_lock();
+	if (!is_cpuset_online(cs))
+		goto out_unlock;
+
+	switch (type) {
+	case FILE_SCHED_RELAX_DOMAIN_LEVEL:
+		retval = update_relax_domain_level(cs, val);
+		break;
+	default:
+		retval = -EINVAL;
+		break;
+	}
+out_unlock:
+	cpuset_unlock();
+	cpus_read_unlock();
+	return retval;
+}
+
+s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
+{
+	struct cpuset *cs = css_cs(css);
+	cpuset_filetype_t type = cft->private;
+
+	switch (type) {
+	case FILE_SCHED_RELAX_DOMAIN_LEVEL:
+		return cs->relax_domain_level;
+	default:
+		BUG();
+	}
+
+	/* Unreachable but makes gcc happy */
+	return 0;
+}

kernel/cgroup/cpuset.c

@@ -1075,7 +1075,7 @@ partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
  *
  * Call with cpuset_mutex held.  Takes cpus_read_lock().
  */
-static void rebuild_sched_domains_locked(void)
+void rebuild_sched_domains_locked(void)
 {
 	struct cgroup_subsys_state *pos_css;
 	struct sched_domain_attr *attr;
@@ -1127,7 +1127,7 @@ static void rebuild_sched_domains_locked(void)
 	partition_and_rebuild_sched_domains(ndoms, doms, attr);
 }
 #else /* !CONFIG_SMP */
-static void rebuild_sched_domains_locked(void)
+void rebuild_sched_domains_locked(void)
 {
 }
 #endif /* CONFIG_SMP */
@@ -2794,23 +2794,6 @@ bool current_cpuset_is_being_rebound(void)
 	return ret;
 }
 
-static int update_relax_domain_level(struct cpuset *cs, s64 val)
-{
-#ifdef CONFIG_SMP
-	if (val < -1 || val > sched_domain_level_max + 1)
-		return -EINVAL;
-#endif
-
-	if (val != cs->relax_domain_level) {
-		cs->relax_domain_level = val;
-		if (!cpumask_empty(cs->cpus_allowed) &&
-		    is_sched_load_balance(cs))
-			rebuild_sched_domains_locked();
-	}
-
-	return 0;
-}
-
 /**
  * update_tasks_flags - update the spread flags of tasks in the cpuset.
  * @cs: the cpuset in which each task's spread flags needs to be changed
@@ -3273,32 +3256,6 @@ out_unlock:
 	return retval;
 }
 
-static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
-			    s64 val)
-{
-	struct cpuset *cs = css_cs(css);
-	cpuset_filetype_t type = cft->private;
-	int retval = -ENODEV;
-
-	cpus_read_lock();
-	mutex_lock(&cpuset_mutex);
-	if (!is_cpuset_online(cs))
-		goto out_unlock;
-
-	switch (type) {
-	case FILE_SCHED_RELAX_DOMAIN_LEVEL:
-		retval = update_relax_domain_level(cs, val);
-		break;
-	default:
-		retval = -EINVAL;
-		break;
-	}
-out_unlock:
-	mutex_unlock(&cpuset_mutex);
-	cpus_read_unlock();
-	return retval;
-}
-
 /*
  * Common handling for a write to a "cpus" or "mems" file.
  */
@@ -3449,21 +3406,6 @@ static u64 cpuset_read_u64(struct cgroup_subsys_state *css, struct cftype *cft)
 	return 0;
 }
 
-static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
-{
-	struct cpuset *cs = css_cs(css);
-	cpuset_filetype_t type = cft->private;
-	switch (type) {
-	case FILE_SCHED_RELAX_DOMAIN_LEVEL:
-		return cs->relax_domain_level;
-	default:
-		BUG();
-	}
-
-	/* Unreachable but makes gcc happy */
-	return 0;
-}
-
 static int sched_partition_show(struct seq_file *seq, void *v)
 {
 	struct cpuset *cs = css_cs(seq_css(seq));