On Sat, Feb 23, 2019 at 01:34:31AM -0500, Joel Fernandes (Google) wrote: > Recently I added an RCU annotation check to rcu_assign_pointer(). All > pointers assigned to RCU protected data are to be annotated with __rcu > inorder to be able to use rcu_assign_pointer() similar to checks in > other RCU APIs. > > This resulted in a sparse error: kernel//sched/cpufreq.c:41:9: sparse: > error: incompatible types in comparison expression (different address > spaces) > > Fix this by annotating cpufreq_update_util_data pointer with __rcu. This > will also help sparse catch any future RCU misuage bugs. > > Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> >From an RCU perspective: Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx> > --- > kernel/sched/cpufreq.c | 2 +- > kernel/sched/sched.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c > index 22bd8980f32f..e316ee7bb2e5 100644 > --- a/kernel/sched/cpufreq.c > +++ b/kernel/sched/cpufreq.c > @@ -7,7 +7,7 @@ > */ > #include "sched.h" > > -DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); > +DEFINE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); > > /** > * cpufreq_add_update_util_hook - Populate the CPU's update_util_data pointer. > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > index d04530bf251f..2ab545d40381 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -2166,7 +2166,7 @@ static inline u64 irq_time_read(int cpu) > #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ > > #ifdef CONFIG_CPU_FREQ > -DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); > +DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); > > /** > * cpufreq_update_util - Take a note about CPU utilization changes. > -- > 2.21.0.rc0.258.g878e2cd30e-goog >
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