From: Frederic Weisbecker <fweis...@gmail.com>
If we enqueue an rcu callback, we need the CPU tick to stay
alive until we take care of those by completing the appropriate
grace period.
Thus, when we call_rcu(), send a self IPI that checks rcu_needs_cpu()
so that we restore a periodic tick behaviour that can take care of
everything.
Signed-off-by: Frederic Weisbecker <fweis...@gmail.com>
Cc: Alessio Igor Bogani <abog...@kernel.org>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Avi Kivity <a...@redhat.com>
Cc: Chris Metcalf <cmetc...@tilera.com>
Cc: Christoph Lameter <c...@linux.com>
Cc: Daniel Lezcano <daniel.lezc...@linaro.org>
Cc: Geoff Levand <ge...@infradead.org>
Cc: Gilad Ben Yossef <gi...@benyossef.com>
Cc: Hakan Akkan <hakanak...@gmail.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Kevin Hilman <khil...@ti.com>
Cc: Max Krasnyansky <m...@qualcomm.com>
Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephen Hemminger <shemmin...@vyatta.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporat...@gmail.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Steven Rostedt <rost...@goodmis.org>
---
kernel/rcutree.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 21664a3..7dce432 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -2081,6 +2081,13 @@ static void invoke_rcu_core(void)
static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,
struct rcu_head *head, unsigned long flags)
{
+ /* Restart the timer if needed to handle the callbacks */
+ if (cpuset_adaptive_nohz()) {
+ /* Make updates on nxtlist visible to self IPI */
+ barrier();
+ smp_cpuset_update_nohz(smp_processor_id());
+ }
+
/*
* If called from an extended quiescent state, invoke the RCU
* core in order to force a re-evaluation of RCU's idleness.
--
1.7.10.4
--
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