sched/cpufreq: Annotate cpufreq_update_util_data pointer with __rcu

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) <[email protected]>
[ From an RCU perspective. ]
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Paul E. McKenney <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Van Oostenryck <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Morten Rasmussen <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Joel Fernandes (Google) 2019-03-20 20:34:23 -04:00 • committed by Ingo Molnar
commit b10abd0a88
2 changed files with 2 additions and 2 deletions

View file

@ -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.

View file

@ -2185,7 +2185,7 @@ 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.