procfs: Use vtime aware kcpustat accessor to fetch CPUTIME_SYSTEM

Now that we have a vtime safe kcpustat accessor for CPUTIME_SYSTEM, use
it to start fixing frozen kcpustat values on nohz_full CPUs.

Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rjw@rjwysocki.net>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Link: https://lkml.kernel.org/r/20191016025700.31277-13-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 80c305f206bba89a9cb1e6b72074fdf9e1d0e713..5c6bd0ae38022374d6bb1908ac1ccc05603b3e39 100644 (file)
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -124,7 +124,7 @@ static int show_stat(struct seq_file *p, void *v)
 
                user += kcs->cpustat[CPUTIME_USER];
                nice += kcs->cpustat[CPUTIME_NICE];
-               system += kcs->cpustat[CPUTIME_SYSTEM];
+               system += kcpustat_field(kcs, CPUTIME_SYSTEM, i);
                idle += get_idle_time(kcs, i);
                iowait += get_iowait_time(kcs, i);
                irq += kcs->cpustat[CPUTIME_IRQ];
@@ -162,7 +162,7 @@ static int show_stat(struct seq_file *p, void *v)
                /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
                user = kcs->cpustat[CPUTIME_USER];
                nice = kcs->cpustat[CPUTIME_NICE];
-               system = kcs->cpustat[CPUTIME_SYSTEM];
+               system = kcpustat_field(kcs, CPUTIME_SYSTEM, i);
                idle = get_idle_time(kcs, i);
                iowait = get_iowait_time(kcs, i);
                irq = kcs->cpustat[CPUTIME_IRQ];