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    SubjectRe: [PATCH 13/25] context_tracking: Introduce context_tracking_enabled_cpu()
    On Wed, Nov 14, 2018 at 03:45:57AM +0100, Frederic Weisbecker wrote:
    > This allows us to check if a remote CPU runs context tracking
    > (ie: is nohz_full). We'll need that to reliably support "nice"
    > accounting on kcpustat.
    >
    > 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>
    > ---
    > include/linux/context_tracking_state.h | 6 ++++++
    > 1 file changed, 6 insertions(+)
    >
    > diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h
    > index 08f125f..5877177 100644
    > --- a/include/linux/context_tracking_state.h
    > +++ b/include/linux/context_tracking_state.h
    > @@ -31,6 +31,11 @@ static inline bool context_tracking_enabled(void)
    > return static_branch_unlikely(&context_tracking_key);
    > }
    >
    > +static inline bool context_tracking_enabled_cpu(int cpu)
    > +{
    > + return per_cpu(context_tracking.active, cpu);
    > +}
    > +
    > static inline bool context_tracking_enabled_this_cpu(void)
    > {
    > return __this_cpu_read(context_tracking.active);

    Should not the last two be something like:

    static inline bool context_tracking_enabled_cpu(int cpu)
    {
    return context_tracking_enabled() && per_cpu(context_tracking.active, cpu);
    }

    static inline bool context_tracking_enabled_this_cpu(void)
    {
    return context_tracking_enabled() && __this_cpu_read(context_tracking.active);
    }

    Because, afaict, not all callsites first check the static key.

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