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_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index c97b468ee9f7..118bff73fed3 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -95,27 +95,26 @@ static struct dbs_tuners {
         .freq_step = 5,
 };
 
-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)
@@ -272,7 +271,7 @@ 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;
 }
@@ -362,11 +361,11 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
                 j_dbs_info->prev_cpu_idle = cur_idle_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
@@ -374,7 +373,7 @@ 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);
                 }
 
@@ -501,10 +500,9 @@ 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->down_skip = 0;
                 this_dbs_info->requested_freq = policy->cur;