[PATCH tip/core/rcu 01/12] sched: Replace call_rcu_sched() with call_rcu()

From: Paul E. McKenney
Date: Wed Jan 09 2019 - 16:19:09 EST


Now that call_rcu()'s callback is not invoked until after all
preempt-disable regions of code have completed (in addition to explicitly
marked RCU read-side critical sections), call_rcu() can be used in place
of call_rcu_sched(). This commit therefore makes that change.

While in the area, this commit also updates an outdated header comment
for for_each_domain().

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
kernel/sched/sched.h | 2 +-
kernel/sched/topology.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index d04530bf251f..6665b9c02e2f 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1260,7 +1260,7 @@ extern void sched_ttwu_pending(void);

/*
* The domain tree (rq->sd) is protected by RCU's quiescent state transition.
- * See detach_destroy_domains: synchronize_sched for details.
+ * See destroy_sched_domains: call_rcu for details.
*
* The domain tree of any CPU may only be accessed from within
* preempt-disabled sections.
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 3f35ba1d8fde..7d905f55e7fa 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -442,7 +442,7 @@ void rq_attach_root(struct rq *rq, struct root_domain *rd)
raw_spin_unlock_irqrestore(&rq->lock, flags);

if (old_rd)
- call_rcu_sched(&old_rd->rcu, free_rootdomain);
+ call_rcu(&old_rd->rcu, free_rootdomain);
}

void sched_get_rd(struct root_domain *rd)
@@ -455,7 +455,7 @@ void sched_put_rd(struct root_domain *rd)
if (!atomic_dec_and_test(&rd->refcount))
return;

- call_rcu_sched(&rd->rcu, free_rootdomain);
+ call_rcu(&rd->rcu, free_rootdomain);
}

static int init_rootdomain(struct root_domain *rd)
--
2.17.1