linux-kernel - Re: irq 16: nobody cared

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Date:	Sun, 21 Apr 2013 23:42:41 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc:	x86-ml <x86@...nel.org>, lkml <linux-kernel@...r.kernel.org>,
	tiwai@...e.de
Subject: Re: irq 16: nobody cared

On Sun, Apr 21, 2013 at 10:51:39PM +0200, Borislav Petkov wrote:
> A similar oneliner at the end of the resume path.
>
> Maybe have rcu suspend/resume callbacks where you can do this stuff
> and maybe more in the future.

Ok, here's one - it is pretty straight-forward using that notifier
abomination :-). It is only in rcutree.c, it could probably be shared
with rcutiny.c. And it has a section mismatch but I'll fix that too.

It works though - two suspend/resume cycles looked ok.

--
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 986d1d3a34f5..cb1f61ede2f9 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -53,6 +53,7 @@
 #include <linux/delay.h>
 #include <linux/stop_machine.h>
 #include <linux/random.h>
+#include <linux/suspend.h>
 
 #include "rcutree.h"
 #include <trace/events/rcu.h>
@@ -3097,6 +3098,22 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
 	return NOTIFY_OK;
 }
 
+static int __cpuinit rcu_pm_notify(struct notifier_block *self,
+				   unsigned long action, void *hcpu)
+{
+	switch (action) {
+	case PM_HIBERNATION_PREPARE:
+		rcu_expedited = 1;
+		break;
+	case PM_POST_RESTORE:
+		rcu_expedited = 0;
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_OK;
+}
+
 /*
  * Spawn the kthread that handles this RCU flavor's grace periods.
  */
@@ -3323,6 +3340,7 @@ void __init rcu_init(void)
 	 * or the scheduler are operational.
 	 */
 	cpu_notifier(rcu_cpu_notify, 0);
+	pm_notifier(rcu_pm_notify, 0);
 	for_each_online_cpu(cpu)
 		rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
 }


-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--
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