sched/accounting: Change cpustat fields to an array

This patch changes fields in cpustat from a structure, to an
u64 array. Math gets easier, and the code is more flexible.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Tuner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322498719-2255-2-git-send-email-glommer@parallels.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 18 insertions, 20 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index fa8af4ebb1d..f3d327cee43 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -119,27 +119,26 @@ static struct dbs_tuners {
 	.powersave_bias = 0,
 };
 
-static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
-							cputime64_t *wall)
+static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
 {
-	cputime64_t idle_time;
+	u64 idle_time;
 	cputime64_t cur_wall_time;
-	cputime64_t busy_time;
+	u64 busy_time;
 
 	cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
-	busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
-			kstat_cpu(cpu).cpustat.system);
+	busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER] +
+		    kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
 
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice);
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
 
 	idle_time = cputime64_sub(cur_wall_time, busy_time);
 	if (wall)
-		*wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);
+		*wall = jiffies_to_usecs(cur_wall_time);
 
-	return (cputime64_t)jiffies_to_usecs(idle_time);
+	return jiffies_to_usecs(idle_time);
 }
 
 static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
@@ -345,7 +344,7 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
 		dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
 						&dbs_info->prev_cpu_wall);
 		if (dbs_tuners_ins.ignore_nice)
-			dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
+			dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
 
 	}
 	return count;
@@ -455,11 +454,11 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 		j_dbs_info->prev_cpu_iowait = cur_iowait_time;
 
 		if (dbs_tuners_ins.ignore_nice) {
-			cputime64_t cur_nice;
+			u64 cur_nice;
 			unsigned long cur_nice_jiffies;
 
-			cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice,
-					 j_dbs_info->prev_cpu_nice);
+			cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
+					 j_dbs_info->prev_cpu_nice;
 			/*
 			 * Assumption: nice time between sampling periods will
 			 * be less than 2^32 jiffies for 32 bit sys
@@ -467,7 +466,7 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 			cur_nice_jiffies = (unsigned long)
 					cputime64_to_jiffies64(cur_nice);
 
-			j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
+			j_dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
 			idle_time += jiffies_to_usecs(cur_nice_jiffies);
 		}
 
@@ -646,10 +645,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 
 			j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
 						&j_dbs_info->prev_cpu_wall);
-			if (dbs_tuners_ins.ignore_nice) {
+			if (dbs_tuners_ins.ignore_nice)
 				j_dbs_info->prev_cpu_nice =
-						kstat_cpu(j).cpustat.nice;
-			}
+						kcpustat_cpu(j).cpustat[CPUTIME_NICE];
 		}
 		this_dbs_info->cpu = cpu;
 		this_dbs_info->rate_mult = 1;