[RFC PATCH v2 15/17] sched: Misc preps for cgroup unified hierarchy interface

[Waiman Long]

From: Tejun Heo <tj@xxxxxxxxxx>

Make the following changes in preparation for the cpu controller
interface implementation for the unified hierarchy.  This patch
doesn't cause any functional differences.

* s/cpu_stats_show()/cpu_cfs_stats_show()/

* s/cpu_files/cpu_legacy_files/

* Separate out cpuacct_stats_read() from cpuacct_stats_show().  While
  at it, make the @val array u64 for consistency.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
---
 kernel/sched/core.c    |  8 ++++----
 kernel/sched/cpuacct.c | 29 ++++++++++++++++++-----------
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c888bd3..be2527b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7230,7 +7230,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
 	return ret;
 }
 
-static int cpu_stats_show(struct seq_file *sf, void *v)
+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
 {
 	struct task_group *tg = css_tg(seq_css(sf));
 	struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
@@ -7270,7 +7270,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
 }
 #endif /* CONFIG_RT_GROUP_SCHED */
 
-static struct cftype cpu_files[] = {
+static struct cftype cpu_legacy_files[] = {
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	{
 		.name = "shares",
@@ -7291,7 +7291,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
 	},
 	{
 		.name = "stat",
-		.seq_show = cpu_stats_show,
+		.seq_show = cpu_cfs_stats_show,
 	},
 #endif
 #ifdef CONFIG_RT_GROUP_SCHED
@@ -7317,7 +7317,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
 	.fork		= cpu_cgroup_fork,
 	.can_attach	= cpu_cgroup_can_attach,
 	.attach		= cpu_cgroup_attach,
-	.legacy_cftypes	= cpu_files,
+	.legacy_cftypes	= cpu_legacy_files,
 	.early_init	= true,
 };
 
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index f95ab29..6151c23 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -276,26 +276,33 @@ static int cpuacct_all_seq_show(struct seq_file *m, void *V)
 	return 0;
 }
 
-static int cpuacct_stats_show(struct seq_file *sf, void *v)
+static void cpuacct_stats_read(struct cpuacct *ca,
+			       u64 (*val)[CPUACCT_STAT_NSTATS])
 {
-	struct cpuacct *ca = css_ca(seq_css(sf));
-	s64 val[CPUACCT_STAT_NSTATS];
 	int cpu;
-	int stat;
 
-	memset(val, 0, sizeof(val));
+	memset(val, 0, sizeof(*val));
+
 	for_each_possible_cpu(cpu) {
 		u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
 
-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
 	}
+}
+
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
+{
+	u64 val[CPUACCT_STAT_NSTATS];
+	int stat;
+
+	cpuacct_stats_read(css_ca(seq_css(sf)), &val);
 
 	for (stat = 0; stat < CPUACCT_STAT_NSTATS; stat++) {
-		seq_printf(sf, "%s %lld\n",
+		seq_printf(sf, "%s %llu\n",
 			   cpuacct_stat_desc[stat],
 			   (long long)nsec_to_clock_t(val[stat]));
 	}
-- 
1.8.3.1