[PATCH tip/core/rcu 07/26] rcu: Grace-period-kthread related sleeps to idle priority

paulmck
2020-06-23T00:23:10Z

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit converts the long-standing schedule_timeout_interruptible()
and schedule_timeout_uninterruptible() calls used by RCU's grace-period
kthread to schedule_timeout_idle(). This conversion avoids polluting
the load-average with RCU-related sleeping.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/tree.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index db17ffe..48ae673 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1620,7 +1620,7 @@ static void rcu_gp_slow(int delay)
if (delay > 0 &&
!(rcu_seq_ctr(rcu_state.gp_seq) %
(rcu_num_nodes * PER_RCU_NODE_PERIOD * delay)))
- schedule_timeout_uninterruptible(delay);
+ schedule_timeout_idle(delay);
}

static unsigned long sleep_duration;
@@ -1643,7 +1643,7 @@ static void rcu_gp_torture_wait(void)
duration = xchg(&sleep_duration, 0UL);
if (duration > 0) {
pr_alert("%s: Waiting %lu jiffies\n", __func__, duration);
- schedule_timeout_uninterruptible(duration);
+ schedule_timeout_idle(duration);
pr_alert("%s: Wait complete\n", __func__);
}
}
@@ -2709,7 +2709,7 @@ static void rcu_cpu_kthread(unsigned int cpu)
}
*statusp = RCU_KTHREAD_YIELDING;
trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
- schedule_timeout_interruptible(2);
+ schedule_timeout_idle(2);
trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
*statusp = RCU_KTHREAD_WAITING;
}
--
2.9.5