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 42b274da92c..8a6ab666e9f 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 766b1d45605..0fb22e464e7 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);