rcu/sync: Use call_rcu_flush() instead of call_rcu

joelagnel · chantra · commit 78d263aa10b2 · 2022-10-19T22:22:31.000-07:00
call_rcu() changes to save power will slow down rcu sync. Use the
call_rcu_flush() API instead which reverts to the old behavior.

Signed-off-by: Joel Fernandes (Google) &lt;joel@joelfernandes.org&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@kernel.org&gt;
diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c
@@ -44,7 +44,7 @@ static void rcu_sync_func(struct rcu_head *rhp);
 
 static void rcu_sync_call(struct rcu_sync *rsp)
 {
-	call_rcu(&rsp->cb_head, rcu_sync_func);
+	call_rcu_flush(&rsp->cb_head, rcu_sync_func);
 }
 
 /**

Original file line number	Diff line number	Diff line change
`@@ -44,7 +44,7 @@ static void rcu_sync_func(struct rcu_head *rhp);`
`44`	`44`
`45`	`45`	`static void rcu_sync_call(struct rcu_sync *rsp)`
`46`	`46`	`{`
`47`		`- call_rcu(&rsp->cb_head, rcu_sync_func);`
	`47`	`+ call_rcu_flush(&rsp->cb_head, rcu_sync_func);`
`48`	`48`	`}`
`49`	`49`
`50`	`50`	`/**`