From: "Joel Fernandes (Google)" <j...@joelfernandes.org> get_cpu_var disables preemption which has the potential to call into the preemption disable trace points causing some complications. There's also no need to disable preemption in uses of get_lock_stats anyway since preempt is already disabled. So lets simplify the code.
Link: http://lkml.kernel.org/r/20180730222423.196630-2-j...@joelfernandes.org Suggested-by: Peter Zijlstra <pet...@infradead.org> Acked-by: Peter Zijlstra <pet...@infradead.org> Signed-off-by: Joel Fernandes (Google) <j...@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> --- kernel/locking/lockdep.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 5fa4d3138bf1..fbbb79d5cfa0 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -248,12 +248,7 @@ void clear_lock_stats(struct lock_class *class) static struct lock_class_stats *get_lock_stats(struct lock_class *class) { - return &get_cpu_var(cpu_lock_stats)[class - lock_classes]; -} - -static void put_lock_stats(struct lock_class_stats *stats) -{ - put_cpu_var(cpu_lock_stats); + return &this_cpu_ptr(cpu_lock_stats)[class - lock_classes]; } static void lock_release_holdtime(struct held_lock *hlock) @@ -271,7 +266,6 @@ static void lock_release_holdtime(struct held_lock *hlock) lock_time_inc(&stats->read_holdtime, holdtime); else lock_time_inc(&stats->write_holdtime, holdtime); - put_lock_stats(stats); } #else static inline void lock_release_holdtime(struct held_lock *hlock) @@ -4090,7 +4084,6 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip) stats->contending_point[contending_point]++; if (lock->cpu != smp_processor_id()) stats->bounces[bounce_contended + !!hlock->read]++; - put_lock_stats(stats); } static void @@ -4138,7 +4131,6 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip) } if (lock->cpu != cpu) stats->bounces[bounce_acquired + !!hlock->read]++; - put_lock_stats(stats); lock->cpu = cpu; lock->ip = ip; -- 2.18.0
