On Fri, May 01, 2015 at 08:08:48AM -0700, Paul E. McKenney wrote:

On Thu, Apr 30, 2015 at 10:50:55AM +0100, Catalin Marinas wrote:

quoted

On Thu, Apr 23, 2015 at 01:07:33PM -0700, Paul E. McKenney wrote:

quoted

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 328b8ce4b007..6dc727a6e73e 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c

@@ -252,15 +252,13 @@ static int op_cpu_kill(unsigned int cpu)
 	return cpu_ops[cpu]->cpu_kill(cpu);
 }
 
-static DECLARE_COMPLETION(cpu_died);
-
 /*
  * called on the thread which is asking for a CPU to be shutdown -
  * waits until shutdown has completed, or it is timed out.
  */
 void __cpu_die(unsigned int cpu)
 {
-	if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
+	if (!cpu_wait_death(cpu, 5)) {
 		pr_crit("CPU%u: cpu didn't die\n", cpu);
 		return;
 	}

@@ -293,7 +291,7 @@ void cpu_die(void)
 	local_irq_disable();
 
 	/* Tell __cpu_die() that this CPU is now safe to dispose of */
-	complete(&cpu_died);
+	(void)cpu_report_death();
 
 	/*
 	 * Actually shutdown the CPU. This must never fail. The specific hotplug

Are these functions are only defined when HOTPLUG_CPU is enabled? On
arm64 we can end up with this option disabled if SUSPEND is disabled.

Yep, only with HOTPLUG_CPU.  And yes, both SUSPEND and HIBERNATION can
force HOTPLUG_CPU, so if you have neiter SUSPEND nor HIBERNATION, you
won't have HOTPLUG_CPU.  This -should- be OK, because you should also
not have __cpu_die() if !HOTPLUG_CPU.

Ah, you are right. I got myself confused.

So is this patch ready for upstreaming or just for our information?

-- 
Catalin