[tip: core/rcu] rcu: Expedited grace-period sleeps to idle priority

[tip-bot2 for Paul E. McKenney]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     68c2f27e01f61760e6ae76fff9682e1ffe9bacb6
Gitweb:        https://git.kernel.org/tip/68c2f27e01f61760e6ae76fff9682e1ffe9bacb6
Author:        Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate:    Thu, 07 May 2020 16:38:29 -07:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 29 Jun 2020 11:58:50 -07:00

rcu: Expedited grace-period sleeps to idle priority

This commit converts the schedule_timeout_uninterruptible() call used
by RCU's expedited grace-period processing to schedule_timeout_idle().
This conversion avoids polluting the load-average with RCU-related
sleeping.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/rcu/tree_exp.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 72952ed..1888c0e 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -403,7 +403,7 @@ retry_ipi:
 			/* Online, so delay for a bit and try again. */
 			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("selectofl"));
-			schedule_timeout_uninterruptible(1);
+			schedule_timeout_idle(1);
 			goto retry_ipi;
 		}
 		/* CPU really is offline, so we must report its QS. */