Commit b201fa67 authored Nov 25, 2016 by Paul E. McKenney

rcu: Remove short-term CPU kicking

Commit 4914950a ("rcu: Stop treating in-kernel CPU-bound workloads
as errors") added a (relatively) short-timeout call to resched_cpu().
This was inspired by as issue that was fixed by b7e7ade3 ("sched/core:
Fix remote wakeups"). But given that this issue was fixed, it is time
for the current commit to remove this call to resched_cpu().

Reported-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

parent 28053bc7

kernel/rcu/tree.c

+0 −5

Original line number	Diff line number	Diff line
		@@ -1220,11 +1220,6 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
		rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */
		}

		/* And if it has been a really long time, kick the CPU as well. */
		if (ULONG_CMP_GE(jiffies,
		rdp->rsp->gp_start + 2 * jiffies_till_sched_qs) \|\|
		ULONG_CMP_GE(jiffies, rdp->rsp->gp_start + jiffies_till_sched_qs))
		resched_cpu(rdp->cpu); /* Force CPU into scheduler. */
		/*
		* If more than halfway to RCU CPU stall-warning time, do
		* a resched_cpu() to try to loosen things up a bit.