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>

2 files changed, 31 insertions, 36 deletions

diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 42b274da92c3..8a6ab666e9f8 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -22,29 +22,27 @@
 #define arch_idle_time(cpu) 0
 #endif
 
-static cputime64_t get_idle_time(int cpu)
+static u64 get_idle_time(int cpu)
 {
-        u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
-        cputime64_t idle;
+        u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL);
 
         if (idle_time == -1ULL) {
                 /* !NO_HZ so we can rely on cpustat.idle */
-                idle = kstat_cpu(cpu).cpustat.idle;
-                idle = cputime64_add(idle, arch_idle_time(cpu));
+                idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
+                idle += arch_idle_time(cpu);
         } else
                 idle = usecs_to_cputime(idle_time);
 
         return idle;
 }
 
-static cputime64_t get_iowait_time(int cpu)
+static u64 get_iowait_time(int cpu)
 {
-        u64 iowait_time = get_cpu_iowait_time_us(cpu, NULL);
-        cputime64_t iowait;
+        u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL);
 
         if (iowait_time == -1ULL)
                 /* !NO_HZ so we can rely on cpustat.iowait */
-                iowait = kstat_cpu(cpu).cpustat.iowait;
+                iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
         else
                 iowait = usecs_to_cputime(iowait_time);
 
@@ -55,33 +53,30 @@ static int show_stat(struct seq_file *p, void *v)
 {
         int i, j;
         unsigned long jif;
-        cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;
-        cputime64_t guest, guest_nice;
+        u64 user, nice, system, idle, iowait, irq, softirq, steal;
+        u64 guest, guest_nice;
         u64 sum = 0;
         u64 sum_softirq = 0;
         unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
         struct timespec boottime;
 
         user = nice = system = idle = iowait =
-                irq = softirq = steal = cputime64_zero;
-        guest = guest_nice = cputime64_zero;
+                irq = softirq = steal = 0;
+        guest = guest_nice = 0;
         getboottime(&boottime);
         jif = boottime.tv_sec;
 
         for_each_possible_cpu(i) {
-                user = cputime64_add(user, kstat_cpu(i).cpustat.user);
-                nice = cputime64_add(nice, kstat_cpu(i).cpustat.nice);
-                system = cputime64_add(system, kstat_cpu(i).cpustat.system);
-                idle = cputime64_add(idle, get_idle_time(i));
-                iowait = cputime64_add(iowait, get_iowait_time(i));
-                irq = cputime64_add(irq, kstat_cpu(i).cpustat.irq);
-                softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq);
-                steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);
-                guest = cputime64_add(guest, kstat_cpu(i).cpustat.guest);
-                guest_nice = cputime64_add(guest_nice,
-                        kstat_cpu(i).cpustat.guest_nice);
-                sum += kstat_cpu_irqs_sum(i);
-                sum += arch_irq_stat_cpu(i);
+                user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
+                nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
+                system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
+                idle += get_idle_time(i);
+                iowait += get_iowait_time(i);
+                irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
+                softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
+                steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
+                guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
+                guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
 
                 for (j = 0; j < NR_SOFTIRQS; j++) {
                         unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
@@ -106,16 +101,16 @@ static int show_stat(struct seq_file *p, void *v)
                 (unsigned long long)cputime64_to_clock_t(guest_nice));
         for_each_online_cpu(i) {
                 /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
-                user = kstat_cpu(i).cpustat.user;
-                nice = kstat_cpu(i).cpustat.nice;
-                system = kstat_cpu(i).cpustat.system;
+                user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
+                nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
+                system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
                 idle = get_idle_time(i);
                 iowait = get_iowait_time(i);
-                irq = kstat_cpu(i).cpustat.irq;
-                softirq = kstat_cpu(i).cpustat.softirq;
-                steal = kstat_cpu(i).cpustat.steal;
-                guest = kstat_cpu(i).cpustat.guest;
-                guest_nice = kstat_cpu(i).cpustat.guest_nice;
+                irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
+                softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
+                steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
+                guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
+                guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
                 seq_printf(p,
                         "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu "
                         "%llu\n",
diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c
index 766b1d456050..0fb22e464e72 100644
--- a/fs/proc/uptime.c
+++ b/fs/proc/uptime.c
@@ -12,10 +12,10 @@ static int uptime_proc_show(struct seq_file *m, void *v)
         struct timespec uptime;
         struct timespec idle;
         int i;
-        cputime_t idletime = cputime_zero;
+        u64 idletime = 0;
 
         for_each_possible_cpu(i)
-                idletime = cputime64_add(idletime, kstat_cpu(i).cpustat.idle);
+                idletime += kcpustat_cpu(i).cpustat[CPUTIME_IDLE];
 
         do_posix_clock_monotonic_gettime(&uptime);
         monotonic_to_bootbased(&uptime);