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>

9 files changed, 142 insertions, 141 deletions

diff --git a/arch/s390/appldata/appldata_os.c b/arch/s390/appldata/appldata_os.c
index 92f1cb7..4de031d6 100644
--- a/arch/s390/appldata/appldata_os.c
+++ b/arch/s390/appldata/appldata_os.c
@@ -115,21 +115,21 @@ static void appldata_get_os_data(void *data)
 	j = 0;
 	for_each_online_cpu(i) {
 		os_data->os_cpu[j].per_cpu_user =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.user);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_USER]);
 		os_data->os_cpu[j].per_cpu_nice =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.nice);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_NICE]);
 		os_data->os_cpu[j].per_cpu_system =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.system);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM]);
 		os_data->os_cpu[j].per_cpu_idle =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.idle);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IDLE]);
 		os_data->os_cpu[j].per_cpu_irq =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.irq);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IRQ]);
 		os_data->os_cpu[j].per_cpu_softirq =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.softirq);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]);
 		os_data->os_cpu[j].per_cpu_iowait =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.iowait);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IOWAIT]);
 		os_data->os_cpu[j].per_cpu_steal =
-			cputime_to_jiffies(kstat_cpu(i).cpustat.steal);
+			cputime_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_STEAL]);
 		os_data->os_cpu[j].cpu_id = i;
 		j++;
 	}
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index c9e09ea..6919e93 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -218,7 +218,7 @@ static inline void fpu_fxsave(struct fpu *fpu)
 #ifdef CONFIG_SMP
 #define safe_address (__per_cpu_offset[0])
 #else
-#define safe_address (kstat_cpu(0).cpustat.user)
+#define safe_address (__get_cpu_var(kernel_cpustat).cpustat[CPUTIME_USER])
 #endif
 
 /*
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index c97b468..118bff7 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;
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index fa8af4e..f3d327c 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;
diff --git a/drivers/macintosh/rack-meter.c b/drivers/macintosh/rack-meter.c
index 2637c13..66d7f1c7 100644
--- a/drivers/macintosh/rack-meter.c
+++ b/drivers/macintosh/rack-meter.c
@@ -81,13 +81,13 @@ static int rackmeter_ignore_nice;
  */
 static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
 {
-	cputime64_t retval;
+	u64 retval;
 
-	retval = cputime64_add(kstat_cpu(cpu).cpustat.idle,
-			kstat_cpu(cpu).cpustat.iowait);
+	retval = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE] +
+		 kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
 
 	if (rackmeter_ignore_nice)
-		retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice);
+		retval += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
 
 	return retval;
 }
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 42b274d..8a6ab66 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 766b1d4..0fb22e4 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);
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 0cce2db..2fbd905 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -6,6 +6,7 @@
 #include <linux/percpu.h>
 #include <linux/cpumask.h>
 #include <linux/interrupt.h>
+#include <linux/sched.h>
 #include <asm/irq.h>
 #include <asm/cputime.h>
 
@@ -15,21 +16,25 @@
  * used by rstatd/perfmeter
  */
 
-struct cpu_usage_stat {
-	cputime64_t user;
-	cputime64_t nice;
-	cputime64_t system;
-	cputime64_t softirq;
-	cputime64_t irq;
-	cputime64_t idle;
-	cputime64_t iowait;
-	cputime64_t steal;
-	cputime64_t guest;
-	cputime64_t guest_nice;
+enum cpu_usage_stat {
+	CPUTIME_USER,
+	CPUTIME_NICE,
+	CPUTIME_SYSTEM,
+	CPUTIME_SOFTIRQ,
+	CPUTIME_IRQ,
+	CPUTIME_IDLE,
+	CPUTIME_IOWAIT,
+	CPUTIME_STEAL,
+	CPUTIME_GUEST,
+	CPUTIME_GUEST_NICE,
+	NR_STATS,
+};
+
+struct kernel_cpustat {
+	u64 cpustat[NR_STATS];
 };
 
 struct kernel_stat {
-	struct cpu_usage_stat	cpustat;
 #ifndef CONFIG_GENERIC_HARDIRQS
        unsigned int irqs[NR_IRQS];
 #endif
@@ -38,10 +43,13 @@ struct kernel_stat {
 };
 
 DECLARE_PER_CPU(struct kernel_stat, kstat);
+DECLARE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
 
-#define kstat_cpu(cpu)	per_cpu(kstat, cpu)
 /* Must have preemption disabled for this to be meaningful. */
-#define kstat_this_cpu	__get_cpu_var(kstat)
+#define kstat_this_cpu (&__get_cpu_var(kstat))
+#define kcpustat_this_cpu (&__get_cpu_var(kernel_cpustat))
+#define kstat_cpu(cpu) per_cpu(kstat, cpu)
+#define kcpustat_cpu(cpu) per_cpu(kernel_cpustat, cpu)
 
 extern unsigned long long nr_context_switches(void);
 
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 699ff14..dbbe35f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -896,14 +896,14 @@ static void update_rq_clock_task(struct rq *rq, s64 delta)
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
 static int irqtime_account_hi_update(void)
 {
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
 	unsigned long flags;
 	u64 latest_ns;
 	int ret = 0;
 
 	local_irq_save(flags);
 	latest_ns = this_cpu_read(cpu_hardirq_time);
-	if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->irq))
+	if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat[CPUTIME_IRQ]))
 		ret = 1;
 	local_irq_restore(flags);
 	return ret;
@@ -911,14 +911,14 @@ static int irqtime_account_hi_update(void)
 
 static int irqtime_account_si_update(void)
 {
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
 	unsigned long flags;
 	u64 latest_ns;
 	int ret = 0;
 
 	local_irq_save(flags);
 	latest_ns = this_cpu_read(cpu_softirq_time);
-	if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->softirq))
+	if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat[CPUTIME_SOFTIRQ]))
 		ret = 1;
 	local_irq_restore(flags);
 	return ret;
@@ -2500,8 +2500,10 @@ unlock:
 #endif
 
 DEFINE_PER_CPU(struct kernel_stat, kstat);
+DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
 
 EXPORT_PER_CPU_SYMBOL(kstat);
+EXPORT_PER_CPU_SYMBOL(kernel_cpustat);
 
 /*
  * Return any ns on the sched_clock that have not yet been accounted in
@@ -2563,8 +2565,9 @@ unsigned long long task_sched_runtime(struct task_struct *p)
 void account_user_time(struct task_struct *p, cputime_t cputime,
 		       cputime_t cputime_scaled)
 {
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-	cputime64_t tmp;
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
+	u64 tmp;
+	int index;
 
 	/* Add user time to process. */
 	p->utime = cputime_add(p->utime, cputime);
@@ -2573,10 +2576,9 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
 
 	/* Add user time to cpustat. */
 	tmp = cputime_to_cputime64(cputime);
-	if (TASK_NICE(p) > 0)
-		cpustat->nice = cputime64_add(cpustat->nice, tmp);
-	else
-		cpustat->user = cputime64_add(cpustat->user, tmp);
+
+	index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
+	cpustat[index] += tmp;
 
 	cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime);
 	/* Account for user time used */
@@ -2592,8 +2594,8 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
 static void account_guest_time(struct task_struct *p, cputime_t cputime,
 			       cputime_t cputime_scaled)
 {
-	cputime64_t tmp;
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+	u64 tmp;
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
 
 	tmp = cputime_to_cputime64(cputime);
 
@@ -2605,11 +2607,11 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
 
 	/* Add guest time to cpustat. */
 	if (TASK_NICE(p) > 0) {
-		cpustat->nice = cputime64_add(cpustat->nice, tmp);
-		cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp);
+		cpustat[CPUTIME_NICE] += tmp;
+		cpustat[CPUTIME_GUEST_NICE] += tmp;
 	} else {
-		cpustat->user = cputime64_add(cpustat->user, tmp);
-		cpustat->guest = cputime64_add(cpustat->guest, tmp);
+		cpustat[CPUTIME_USER] += tmp;
+		cpustat[CPUTIME_GUEST] += tmp;
 	}
 }
 
@@ -2622,9 +2624,10 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
  */
 static inline
 void __account_system_time(struct task_struct *p, cputime_t cputime,
-			cputime_t cputime_scaled, cputime64_t *target_cputime64)
+			cputime_t cputime_scaled, int index)
 {
-	cputime64_t tmp = cputime_to_cputime64(cputime);
+	u64 tmp = cputime_to_cputime64(cputime);
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
 
 	/* Add system time to process. */
 	p->stime = cputime_add(p->stime, cputime);
@@ -2632,7 +2635,7 @@ void __account_system_time(struct task_struct *p, cputime_t cputime,
 	account_group_system_time(p, cputime);
 
 	/* Add system time to cpustat. */
-	*target_cputime64 = cputime64_add(*target_cputime64, tmp);
+	cpustat[index] += tmp;
 	cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime);
 
 	/* Account for system time used */
@@ -2649,8 +2652,7 @@ void __account_system_time(struct task_struct *p, cputime_t cputime,
 void account_system_time(struct task_struct *p, int hardirq_offset,
 			 cputime_t cputime, cputime_t cputime_scaled)
 {
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-	cputime64_t *target_cputime64;
+	int index;
 
 	if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
 		account_guest_time(p, cputime, cputime_scaled);
@@ -2658,13 +2660,13 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
 	}
 
 	if (hardirq_count() - hardirq_offset)
-		target_cputime64 = &cpustat->irq;
+		index = CPUTIME_IRQ;
 	else if (in_serving_softirq())
-		target_cputime64 = &cpustat->softirq;
+		index = CPUTIME_SOFTIRQ;
 	else
-		target_cputime64 = &cpustat->system;
+		index = CPUTIME_SYSTEM;
 
-	__account_system_time(p, cputime, cputime_scaled, target_cputime64);
+	__account_system_time(p, cputime, cputime_scaled, index);
 }
 
 /*
@@ -2673,10 +2675,10 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
  */
 void account_steal_time(cputime_t cputime)
 {
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-	cputime64_t cputime64 = cputime_to_cputime64(cputime);
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
+	u64 cputime64 = cputime_to_cputime64(cputime);
 
-	cpustat->steal = cputime64_add(cpustat->steal, cputime64);
+	cpustat[CPUTIME_STEAL] += cputime64;
 }
 
 /*
@@ -2685,14 +2687,14 @@ void account_steal_time(cputime_t cputime)
  */
 void account_idle_time(cputime_t cputime)
 {
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-	cputime64_t cputime64 = cputime_to_cputime64(cputime);
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
+	u64 cputime64 = cputime_to_cputime64(cputime);
 	struct rq *rq = this_rq();
 
 	if (atomic_read(&rq->nr_iowait) > 0)
-		cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
+		cpustat[CPUTIME_IOWAIT] += cputime64;
 	else
-		cpustat->idle = cputime64_add(cpustat->idle, cputime64);
+		cpustat[CPUTIME_IDLE] += cputime64;
 }
 
 static __always_inline bool steal_account_process_tick(void)
@@ -2742,16 +2744,16 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
 						struct rq *rq)
 {
 	cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
-	cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy);
-	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+	u64 tmp = cputime_to_cputime64(cputime_one_jiffy);
+	u64 *cpustat = kcpustat_this_cpu->cpustat;
 
 	if (steal_account_process_tick())
 		return;
 
 	if (irqtime_account_hi_update()) {
-		cpustat->irq = cputime64_add(cpustat->irq, tmp);
+		cpustat[CPUTIME_IRQ] += tmp;
 	} else if (irqtime_account_si_update()) {
-		cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
+		cpustat[CPUTIME_SOFTIRQ] += tmp;
 	} else if (this_cpu_ksoftirqd() == p) {
 		/*
 		 * ksoftirqd time do not get accounted in cpu_softirq_time.
@@ -2759,7 +2761,7 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
 		 * Also, p->stime needs to be updated for ksoftirqd.
 		 */
 		__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
-					&cpustat->softirq);
+					CPUTIME_SOFTIRQ);
 	} else if (user_tick) {
 		account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
 	} else if (p == rq->idle) {
@@ -2768,7 +2770,7 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
 		account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled);
 	} else {
 		__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
-					&cpustat->system);
+					CPUTIME_SYSTEM);
 	}
 }