sched: Rely on synchronize_rcu_mult() de-duplication

The synchronize_rcu_mult() function now detects duplicate requests
for the same grace-period flavor and waits only once for each flavor.
This commit therefore removes the ugly #ifdef from sched_cpu_deactivate()
because synchronize_rcu_mult(call_rcu, call_rcu_sched) now does what
the #ifdef used to be needed for.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Paul E. McKenney 2017-04-28 16:33:07 -07:00
parent 68ab0b4263
commit d7d34d5e46

View file

@ -5874,15 +5874,9 @@ int sched_cpu_deactivate(unsigned int cpu)
* users of this state to go away such that all new such users will
* observe it.
*
* For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might
* not imply sync_sched(), so wait for both.
*
* Do sync before park smpboot threads to take care the rcu boost case.
*/
if (IS_ENABLED(CONFIG_PREEMPT))
synchronize_rcu_mult(call_rcu, call_rcu_sched);
else
synchronize_rcu();
synchronize_rcu_mult(call_rcu, call_rcu_sched);
if (!sched_smp_initialized)
return 0;