Re: [PATCH 5/6] leds: Use all-in-one vtime aware kcpustat accessor

From: Frederic Weisbecker
Date: Thu Nov 21 2019 - 09:14:17 EST


On Thu, Nov 21, 2019 at 07:58:26AM +0100, Ingo Molnar wrote:
>
> * Frederic Weisbecker <frederic@xxxxxxxxxx> wrote:
>
> > We can now safely read user kcpustat fields on nohz_full CPUs.
> > Use the appropriate accessor.
> >
> > Reported-by: Yauheni Kaliuta <yauheni.kaliuta@xxxxxxxxxx>
> > Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
> > Cc: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>
> > Cc: Pavel Machek <pavel@xxxxxx>
> > Cc: Yauheni Kaliuta <yauheni.kaliuta@xxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Rik van Riel <riel@xxxxxxxxxxx>
> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Cc: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > ---
> > drivers/leds/trigger/ledtrig-activity.c | 14 +++++++++-----
> > 1 file changed, 9 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/leds/trigger/ledtrig-activity.c b/drivers/leds/trigger/ledtrig-activity.c
> > index ddfc5edd07c8..6901e3631c22 100644
> > --- a/drivers/leds/trigger/ledtrig-activity.c
> > +++ b/drivers/leds/trigger/ledtrig-activity.c
> > @@ -57,11 +57,15 @@ static void led_activity_function(struct timer_list *t)
> > curr_used = 0;
> >
> > for_each_possible_cpu(i) {
> > - curr_used += kcpustat_cpu(i).cpustat[CPUTIME_USER]
> > - + kcpustat_cpu(i).cpustat[CPUTIME_NICE]
> > - + kcpustat_field(&kcpustat_cpu(i), CPUTIME_SYSTEM, i)
> > - + kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]
> > - + kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
> > + struct kernel_cpustat kcpustat;
> > +
> > + kcpustat_fetch_cpu(&kcpustat, i);
> > +
> > + curr_used += kcpustat.cpustat[CPUTIME_USER]
> > + + kcpustat.cpustat[CPUTIME_NICE]
> > + + kcpustat.cpustat[CPUTIME_SYSTEM]
> > + + kcpustat.cpustat[CPUTIME_SOFTIRQ]
> > + + kcpustat.cpustat[CPUTIME_IRQ];
>
> Not the best tested series:
>
> --- a/drivers/leds/trigger/ledtrig-activity.c
> +++ b/drivers/leds/trigger/ledtrig-activity.c
> @@ -59,7 +59,7 @@ static void led_activity_function(struct timer_list *t)
> for_each_possible_cpu(i) {
> struct kernel_cpustat kcpustat;
>
> - kcpustat_fetch_cpu(&kcpustat, i);
> + kcpustat_cpu_fetch(&kcpustat, i);
>
> curr_used += kcpustat.cpustat[CPUTIME_USER]
> + kcpustat.cpustat[CPUTIME_NICE]
>
>
> :-)

Oops, I tested with vtime on and off but that one slipped under my config.
Do you want me to resend?

Thanks.