| Message ID | 20190223063434.6793-5-joel@joelfernandes.org |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | RCU fixes for rcu_assign_pointer() usage | expand |
On Sat, Feb 23, 2019 at 01:34:32AM -0500, Joel Fernandes (Google) wrote: > The scheduler uses RCU API in various places to access sched_domain > pointers. These cause sparse errors as below. > > Many new errors show up because of an annotation check I added to > rcu_assign_pointer(). Let us annotate the pointers correctly which also > will help sparse catch any potential future bugs. > > This fixes the following sparse errors: > > rt.c:1681:9: error: incompatible types in comparison expression > deadline.c:1904:9: error: incompatible types in comparison expression > core.c:519:9: error: incompatible types in comparison expression > core.c:1634:17: error: incompatible types in comparison expression > fair.c:6193:14: error: incompatible types in comparison expression > fair.c:9883:22: error: incompatible types in comparison expression > fair.c:9897:9: error: incompatible types in comparison expression > sched.h:1287:9: error: incompatible types in comparison expression > topology.c:612:9: error: incompatible types in comparison expression > topology.c:615:9: error: incompatible types in comparison expression > sched.h:1300:9: error: incompatible types in comparison expression > topology.c:618:9: error: incompatible types in comparison expression > sched.h:1287:9: error: incompatible types in comparison expression > topology.c:621:9: error: incompatible types in comparison expression > sched.h:1300:9: error: incompatible types in comparison expression > topology.c:624:9: error: incompatible types in comparison expression > topology.c:671:9: error: incompatible types in comparison expression > stats.c:45:17: error: incompatible types in comparison expression > fair.c:5998:15: error: incompatible types in comparison expression > fair.c:5989:15: error: incompatible types in comparison expression > fair.c:5998:15: error: incompatible types in comparison expression > fair.c:5989:15: error: incompatible types in comparison expression > fair.c:6120:19: error: incompatible types in comparison expression > fair.c:6506:14: error: incompatible types in comparison expression > fair.c:6515:14: error: incompatible types in comparison expression > fair.c:6623:9: error: incompatible types in comparison expression > fair.c:5970:17: error: incompatible types in comparison expression > fair.c:8642:21: error: incompatible types in comparison expression > fair.c:9253:9: error: incompatible types in comparison expression > fair.c:9331:9: error: incompatible types in comparison expression > fair.c:9519:15: error: incompatible types in comparison expression > fair.c:9533:14: error: incompatible types in comparison expression > fair.c:9542:14: error: incompatible types in comparison expression > fair.c:9567:14: error: incompatible types in comparison expression > fair.c:9597:14: error: incompatible types in comparison expression > fair.c:9421:16: error: incompatible types in comparison expression > fair.c:9421:16: error: incompatible types in comparison expression > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> From an RCU perspective: Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com> > --- > include/linux/sched/topology.h | 4 ++-- > kernel/sched/sched.h | 14 +++++++------- > kernel/sched/topology.c | 10 +++++----- > 3 files changed, 14 insertions(+), 14 deletions(-) > > diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h > index c31d3a47a47c..4819c9e01e42 100644 > --- a/include/linux/sched/topology.h > +++ b/include/linux/sched/topology.h > @@ -76,8 +76,8 @@ struct sched_domain_shared { > > struct sched_domain { > /* These fields must be setup */ > - struct sched_domain *parent; /* top domain must be null terminated */ > - struct sched_domain *child; /* bottom domain must be null terminated */ > + struct sched_domain __rcu *parent; /* top domain must be null terminated */ > + struct sched_domain __rcu *child; /* bottom domain must be null terminated */ > struct sched_group *groups; /* the balancing groups of the domain */ > unsigned long min_interval; /* Minimum balance interval ms */ > unsigned long max_interval; /* Maximum balance interval ms */ > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > index 2ab545d40381..ca6a79f57e7a 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -866,8 +866,8 @@ struct rq { > atomic_t nr_iowait; > > #ifdef CONFIG_SMP > - struct root_domain *rd; > - struct sched_domain *sd; > + struct root_domain *rd; > + struct sched_domain __rcu *sd; > > unsigned long cpu_capacity; > unsigned long cpu_capacity_orig; > @@ -1305,13 +1305,13 @@ static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) > return sd; > } > > -DECLARE_PER_CPU(struct sched_domain *, sd_llc); > +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); > DECLARE_PER_CPU(int, sd_llc_size); > DECLARE_PER_CPU(int, sd_llc_id); > -DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); > -DECLARE_PER_CPU(struct sched_domain *, sd_numa); > -DECLARE_PER_CPU(struct sched_domain *, sd_asym_packing); > -DECLARE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); > +DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); > +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); > +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); > +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); > extern struct static_key_false sched_asym_cpucapacity; > > struct sched_group_capacity { > diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c > index 3f35ba1d8fde..0844ee757dad 100644 > --- a/kernel/sched/topology.c > +++ b/kernel/sched/topology.c > @@ -586,13 +586,13 @@ static void destroy_sched_domains(struct sched_domain *sd) > * the cpumask of the domain), this allows us to quickly tell if > * two CPUs are in the same cache domain, see cpus_share_cache(). > */ > -DEFINE_PER_CPU(struct sched_domain *, sd_llc); > +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc); > DEFINE_PER_CPU(int, sd_llc_size); > DEFINE_PER_CPU(int, sd_llc_id); > -DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); > -DEFINE_PER_CPU(struct sched_domain *, sd_numa); > -DEFINE_PER_CPU(struct sched_domain *, sd_asym_packing); > -DEFINE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); > +DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); > +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa); > +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); > +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); > DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); > > static void update_top_cache_domain(int cpu) > -- > 2.21.0.rc0.258.g878e2cd30e-goog >
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index c31d3a47a47c..4819c9e01e42 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -76,8 +76,8 @@ struct sched_domain_shared { struct sched_domain { /* These fields must be setup */ - struct sched_domain *parent; /* top domain must be null terminated */ - struct sched_domain *child; /* bottom domain must be null terminated */ + struct sched_domain __rcu *parent; /* top domain must be null terminated */ + struct sched_domain __rcu *child; /* bottom domain must be null terminated */ struct sched_group *groups; /* the balancing groups of the domain */ unsigned long min_interval; /* Minimum balance interval ms */ unsigned long max_interval; /* Maximum balance interval ms */ diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 2ab545d40381..ca6a79f57e7a 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -866,8 +866,8 @@ struct rq { atomic_t nr_iowait; #ifdef CONFIG_SMP - struct root_domain *rd; - struct sched_domain *sd; + struct root_domain *rd; + struct sched_domain __rcu *sd; unsigned long cpu_capacity; unsigned long cpu_capacity_orig; @@ -1305,13 +1305,13 @@ static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) return sd; } -DECLARE_PER_CPU(struct sched_domain *, sd_llc); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); -DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); -DECLARE_PER_CPU(struct sched_domain *, sd_numa); -DECLARE_PER_CPU(struct sched_domain *, sd_asym_packing); -DECLARE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); +DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); extern struct static_key_false sched_asym_cpucapacity; struct sched_group_capacity { diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 3f35ba1d8fde..0844ee757dad 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -586,13 +586,13 @@ static void destroy_sched_domains(struct sched_domain *sd) * the cpumask of the domain), this allows us to quickly tell if * two CPUs are in the same cache domain, see cpus_share_cache(). */ -DEFINE_PER_CPU(struct sched_domain *, sd_llc); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc); DEFINE_PER_CPU(int, sd_llc_size); DEFINE_PER_CPU(int, sd_llc_id); -DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); -DEFINE_PER_CPU(struct sched_domain *, sd_numa); -DEFINE_PER_CPU(struct sched_domain *, sd_asym_packing); -DEFINE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); +DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); static void update_top_cache_domain(int cpu)
The scheduler uses RCU API in various places to access sched_domain pointers. These cause sparse errors as below. Many new errors show up because of an annotation check I added to rcu_assign_pointer(). Let us annotate the pointers correctly which also will help sparse catch any potential future bugs. This fixes the following sparse errors: rt.c:1681:9: error: incompatible types in comparison expression deadline.c:1904:9: error: incompatible types in comparison expression core.c:519:9: error: incompatible types in comparison expression core.c:1634:17: error: incompatible types in comparison expression fair.c:6193:14: error: incompatible types in comparison expression fair.c:9883:22: error: incompatible types in comparison expression fair.c:9897:9: error: incompatible types in comparison expression sched.h:1287:9: error: incompatible types in comparison expression topology.c:612:9: error: incompatible types in comparison expression topology.c:615:9: error: incompatible types in comparison expression sched.h:1300:9: error: incompatible types in comparison expression topology.c:618:9: error: incompatible types in comparison expression sched.h:1287:9: error: incompatible types in comparison expression topology.c:621:9: error: incompatible types in comparison expression sched.h:1300:9: error: incompatible types in comparison expression topology.c:624:9: error: incompatible types in comparison expression topology.c:671:9: error: incompatible types in comparison expression stats.c:45:17: error: incompatible types in comparison expression fair.c:5998:15: error: incompatible types in comparison expression fair.c:5989:15: error: incompatible types in comparison expression fair.c:5998:15: error: incompatible types in comparison expression fair.c:5989:15: error: incompatible types in comparison expression fair.c:6120:19: error: incompatible types in comparison expression fair.c:6506:14: error: incompatible types in comparison expression fair.c:6515:14: error: incompatible types in comparison expression fair.c:6623:9: error: incompatible types in comparison expression fair.c:5970:17: error: incompatible types in comparison expression fair.c:8642:21: error: incompatible types in comparison expression fair.c:9253:9: error: incompatible types in comparison expression fair.c:9331:9: error: incompatible types in comparison expression fair.c:9519:15: error: incompatible types in comparison expression fair.c:9533:14: error: incompatible types in comparison expression fair.c:9542:14: error: incompatible types in comparison expression fair.c:9567:14: error: incompatible types in comparison expression fair.c:9597:14: error: incompatible types in comparison expression fair.c:9421:16: error: incompatible types in comparison expression fair.c:9421:16: error: incompatible types in comparison expression Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- include/linux/sched/topology.h | 4 ++-- kernel/sched/sched.h | 14 +++++++------- kernel/sched/topology.c | 10 +++++----- 3 files changed, 14 insertions(+), 14 deletions(-)