[PATCH 21/25] procfs: Use vtime aware kcpustat accessor

Frederic Weisbecker
2018-11-14T02:47:07Z

Now that we have a vtime safe kcpustat accessor, use it to fix frozen
kcpustat values on nohz_full CPUs.

Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Ingo Molnar <mingo@kernel.org>
---
fs/proc/stat.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 535eda7..2eed662 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -95,16 +95,20 @@ static int show_stat(struct seq_file *p, void *v)
getboottime64(&boottime);

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];
+ u64 cpu_user, cpu_nice, cpu_sys, cpu_guest, cpu_guest_nice;
+
+ kcpustat_cputime(&kcpustat_cpu(i), i, &cpu_user, &cpu_nice,
+ &cpu_sys, &cpu_guest, &cpu_guest_nice);
+ user += cpu_user;
+ nice += cpu_nice;
+ system += cpu_sys;
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];
+ guest += cpu_guest;
+ guest_nice += guest_nice;
sum += kstat_cpu_irqs_sum(i);
sum += arch_irq_stat_cpu(i);

@@ -130,17 +134,14 @@ static int show_stat(struct seq_file *p, void *v)
seq_putc(p, '\n');

for_each_online_cpu(i) {
+ kcpustat_cputime(&kcpustat_cpu(i), i, &user, &nice,
+ &system, &guest, &guest_nice);
/* 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];
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];
seq_printf(p, "cpu%d", i);
seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
--
2.7.4