tick/broadcast: Return busy when IPI is pending
Tell the idle code not to go deep if the broadcast IPI is about to
arrive.
[ Split out from a larger combo patch ]
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index da7b40f..70b47bc 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -725,11 +725,15 @@
* if the cpu local event is earlier than the
* broadcast event. If the current CPU is in
* the force mask, then we are going to be
- * woken by the IPI right away.
+ * woken by the IPI right away; we return
+ * busy, so the CPU does not try to go deep
+ * idle.
*/
- if (!cpumask_test_cpu(cpu, tick_broadcast_force_mask) &&
- dev->next_event.tv64 < bc->next_event.tv64)
+ if (cpumask_test_cpu(cpu, tick_broadcast_force_mask)) {
+ ret = -EBUSY;
+ } else if (dev->next_event.tv64 < bc->next_event.tv64) {
tick_broadcast_set_event(bc, cpu, dev->next_event);
+ }
}
/*
* If the current CPU owns the hrtimer broadcast
