[RFC/PATCH 2/5] kernel_cpustat: convert to atomic 64-bit accessors
Kevin Hilman
khilman at linaro.org
Wed Feb 20 14:41:39 EST 2013
Use the atomic64_* accessors for all the kernel_cpustat fields to
ensure atomic access on non-64 bit platforms.
Thanks to Mats Liljegren for CGROUP_CPUACCT related fixes.
Cc: Mats Liljegren <mats.liljegren at enea.com>
Signed-off-by: Kevin Hilman <khilman at linaro.org>
---
fs/proc/stat.c | 40 ++++++++++++++++++++--------------------
fs/proc/uptime.c | 2 +-
include/linux/kernel_stat.h | 2 +-
kernel/sched/core.c | 10 +++++-----
kernel/sched/cputime.c | 38 +++++++++++++++++++-------------------
5 files changed, 46 insertions(+), 46 deletions(-)
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index e296572..93f7f30 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -25,7 +25,7 @@ static cputime64_t get_idle_time(int cpu)
{
cputime64_t idle;
- idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
+ idle = atomic64_read(&kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE]);
if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
idle += arch_idle_time(cpu);
return idle;
@@ -35,7 +35,7 @@ static cputime64_t get_iowait_time(int cpu)
{
cputime64_t iowait;
- iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
+ iowait = atomic64_read(&kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]);
if (cpu_online(cpu) && nr_iowait_cpu(cpu))
iowait += arch_idle_time(cpu);
return iowait;
@@ -52,7 +52,7 @@ static u64 get_idle_time(int cpu)
if (idle_time == -1ULL)
/* !NO_HZ or cpu offline so we can rely on cpustat.idle */
- idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
+ idle = atomic64_read(&kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE]);
else
idle = usecs_to_cputime64(idle_time);
@@ -68,7 +68,7 @@ static u64 get_iowait_time(int cpu)
if (iowait_time == -1ULL)
/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
- iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
+ iowait = atomic64_read(&kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]);
else
iowait = usecs_to_cputime64(iowait_time);
@@ -95,16 +95,16 @@ static int show_stat(struct seq_file *p, void *v)
jif = boottime.tv_sec;
for_each_possible_cpu(i) {
- user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
- nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
- system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
+ user += atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_USER]);
+ nice += atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_NICE]);
+ system += atomic64_read(&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];
+ irq += atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_IRQ]);
+ softirq += atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]);
+ steal += atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_STEAL]);
+ guest += atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_GUEST]);
+ guest_nice += atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]);
sum += kstat_cpu_irqs_sum(i);
sum += arch_irq_stat_cpu(i);
@@ -132,16 +132,16 @@ static int show_stat(struct seq_file *p, void *v)
for_each_online_cpu(i) {
/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
- user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
- nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
- system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
+ user = atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_USER]);
+ nice = atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_NICE]);
+ system = atomic64_read(&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];
+ irq = atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_IRQ]);
+ softirq = atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]);
+ steal = atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_STEAL]);
+ guest = atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_GUEST]);
+ guest_nice = atomic64_read(&kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]);
seq_printf(p, "cpu%d", i);
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(user));
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(nice));
diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c
index 9610ac7..10c0f6e 100644
--- a/fs/proc/uptime.c
+++ b/fs/proc/uptime.c
@@ -18,7 +18,7 @@ static int uptime_proc_show(struct seq_file *m, void *v)
idletime = 0;
for_each_possible_cpu(i)
- idletime += (__force u64) kcpustat_cpu(i).cpustat[CPUTIME_IDLE];
+ idletime += atomic64_read(&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 ed5f6ed..45b9f71 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -32,7 +32,7 @@ enum cpu_usage_stat {
};
struct kernel_cpustat {
- u64 cpustat[NR_STATS];
+ atomic64_t cpustat[NR_STATS];
};
struct kernel_stat {
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2fad439..5415e85 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8168,8 +8168,8 @@ static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_USER];
- val += kcpustat->cpustat[CPUTIME_NICE];
+ val += atomic64_read(&kcpustat->cpustat[CPUTIME_USER]);
+ val += atomic64_read(&kcpustat->cpustat[CPUTIME_NICE]);
}
val = cputime64_to_clock_t(val);
cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val);
@@ -8177,9 +8177,9 @@ static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
val = 0;
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_SYSTEM];
- val += kcpustat->cpustat[CPUTIME_IRQ];
- val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
+ val += atomic64_read(&kcpustat->cpustat[CPUTIME_SYSTEM]);
+ val += atomic64_read(&kcpustat->cpustat[CPUTIME_IRQ]);
+ val += atomic64_read(&kcpustat->cpustat[CPUTIME_SOFTIRQ]);
}
val = cputime64_to_clock_t(val);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index ccff275..4c639ee 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -78,14 +78,14 @@ EXPORT_SYMBOL_GPL(irqtime_account_irq);
static int irqtime_account_hi_update(void)
{
- u64 *cpustat = kcpustat_this_cpu->cpustat;
+ atomic64_t *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 (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_IRQ])
+ if (nsecs_to_cputime64(latest_ns) > atomic64_read(&cpustat[CPUTIME_IRQ]));
ret = 1;
local_irq_restore(flags);
return ret;
@@ -93,14 +93,14 @@ static int irqtime_account_hi_update(void)
static int irqtime_account_si_update(void)
{
- u64 *cpustat = kcpustat_this_cpu->cpustat;
+ atomic64_t *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 (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_SOFTIRQ])
+ if (nsecs_to_cputime64(latest_ns) > atomic64_read(&cpustat[CPUTIME_SOFTIRQ]))
ret = 1;
local_irq_restore(flags);
return ret;
@@ -125,7 +125,7 @@ static inline void task_group_account_field(struct task_struct *p, int index,
* is the only cgroup, then nothing else should be necessary.
*
*/
- __get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
+ atomic64_add(tmp, &__get_cpu_var(kernel_cpustat).cpustat[index]);
#ifdef CONFIG_CGROUP_CPUACCT
if (unlikely(!cpuacct_subsys.active))
@@ -135,7 +135,7 @@ static inline void task_group_account_field(struct task_struct *p, int index,
ca = task_ca(p);
while (ca && (ca != &root_cpuacct)) {
kcpustat = this_cpu_ptr(ca->cpustat);
- kcpustat->cpustat[index] += tmp;
+ atomic64_add(tmp, &kcpustat->cpustat[index]);
ca = parent_ca(ca);
}
rcu_read_unlock();
@@ -176,7 +176,7 @@ 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)
{
- u64 *cpustat = kcpustat_this_cpu->cpustat;
+ atomic64_t *cpustat = kcpustat_this_cpu->cpustat;
/* Add guest time to process. */
p->utime += cputime;
@@ -186,11 +186,11 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
/* Add guest time to cpustat. */
if (TASK_NICE(p) > 0) {
- cpustat[CPUTIME_NICE] += (__force u64) cputime;
- cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;
+ atomic64_add((__force u64) cputime, &cpustat[CPUTIME_NICE]);
+ atomic64_add((__force u64) cputime, &cpustat[CPUTIME_GUEST_NICE]);
} else {
- cpustat[CPUTIME_USER] += (__force u64) cputime;
- cpustat[CPUTIME_GUEST] += (__force u64) cputime;
+ atomic64_add((__force u64) cputime, &cpustat[CPUTIME_USER]);
+ atomic64_add((__force u64) cputime, &cpustat[CPUTIME_GUEST]);
}
}
@@ -250,9 +250,9 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
*/
void account_steal_time(cputime_t cputime)
{
- u64 *cpustat = kcpustat_this_cpu->cpustat;
+ atomic64_t *cpustat = kcpustat_this_cpu->cpustat;
- cpustat[CPUTIME_STEAL] += (__force u64) cputime;
+ atomic64_add((__force u64) cputime, &cpustat[CPUTIME_STEAL]);
}
/*
@@ -261,13 +261,13 @@ void account_steal_time(cputime_t cputime)
*/
void account_idle_time(cputime_t cputime)
{
- u64 *cpustat = kcpustat_this_cpu->cpustat;
+ atomic64_t *cpustat = kcpustat_this_cpu->cpustat;
struct rq *rq = this_rq();
if (atomic_read(&rq->nr_iowait) > 0)
- cpustat[CPUTIME_IOWAIT] += (__force u64) cputime;
+ atomic64_add((__force u64) cputime, &cpustat[CPUTIME_IOWAIT]);
else
- cpustat[CPUTIME_IDLE] += (__force u64) cputime;
+ atomic64_add((__force u64) cputime, &cpustat[CPUTIME_IDLE]);
}
static __always_inline bool steal_account_process_tick(void)
@@ -345,15 +345,15 @@ 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);
- u64 *cpustat = kcpustat_this_cpu->cpustat;
+ atomic64_t *cpustat = kcpustat_this_cpu->cpustat;
if (steal_account_process_tick())
return;
if (irqtime_account_hi_update()) {
- cpustat[CPUTIME_IRQ] += (__force u64) cputime_one_jiffy;
+ atomic64_add((__force u64) cputime_one_jiffy, &cpustat[CPUTIME_IRQ]);
} else if (irqtime_account_si_update()) {
- cpustat[CPUTIME_SOFTIRQ] += (__force u64) cputime_one_jiffy;
+ atomic64_add((__force u64) cputime_one_jiffy, &cpustat[CPUTIME_SOFTIRQ]);
} else if (this_cpu_ksoftirqd() == p) {
/*
* ksoftirqd time do not get accounted in cpu_softirq_time.
--
1.8.1.2
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