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@kernel.org>

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 72952edad1e4b168ccfbfd6b0dc3a900966f3728..1888c0eb12160ce85e86415e3cc08fa51d017dd5 100644 (file)
--- 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. */