[tip: core/rcu] rcu: No-CBs-related sleeps to idle priority

From: tip-bot2 for Paul E. McKenney
Date: Fri Jul 31 2020 - 05:25:11 EST


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

Commit-ID: f5ca34643bbd84f514bdeee194c45dd1fb066ef2
Gitweb: https://git.kernel.org/tip/f5ca34643bbd84f514bdeee194c45dd1fb066ef2
Author: Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate: Thu, 07 May 2020 16:36:10 -07:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 29 Jun 2020 11:58:50 -07:00

rcu: No-CBs-related sleeps to idle priority

This commit converts the schedule_timeout_interruptible() call used by
RCU's no-CBs grace-period kthreads 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_plugin.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 25296c1..982fc5b 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2005,7 +2005,7 @@ static void nocb_gp_wait(struct rcu_data *my_rdp)
/* Polling, so trace if first poll in the series. */
if (gotcbs)
trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Poll"));
- schedule_timeout_interruptible(1);
+ schedule_timeout_idle(1);
} else if (!needwait_gp) {
/* Wait for callbacks to appear. */
trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Sleep"));