[PATCH tip/core/rcu 23/41] sched: Replace synchronize_sched() with synchronize_rcu()

Paul E. McKenney
2018-11-11T19:44:25Z

Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu(). This commit therefore makes this change.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
kernel/sched/cpufreq.c | 4 ++--
kernel/sched/cpufreq_schedutil.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c
index 5e54cbcae673..90fee8e01280 100644
--- a/kernel/sched/cpufreq.c
+++ b/kernel/sched/cpufreq.c
@@ -51,8 +51,8 @@ EXPORT_SYMBOL_GPL(cpufreq_add_update_util_hook);
*
* Clear the update_util_data pointer for the given CPU.
*
- * Callers must use RCU-sched callbacks to free any memory that might be
- * accessed via the old update_util_data pointer or invoke synchronize_sched()
+ * Callers must use RCU callbacks to free any memory that might be
+ * accessed via the old update_util_data pointer or invoke synchronize_rcu()
* right after this function to avoid use-after-free.
*/
void cpufreq_remove_update_util_hook(int cpu)
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 3fffad3bc8a8..6a1bb76afbd1 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -839,7 +839,7 @@ static void sugov_stop(struct cpufreq_policy *policy)
for_each_cpu(cpu, policy->cpus)
cpufreq_remove_update_util_hook(cpu);

- synchronize_sched();
+ synchronize_rcu();

if (!policy->fast_switch_enabled) {
irq_work_sync(&sg_policy->irq_work);
--
2.17.1