lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sat, 17 Aug 2013 18:37:46 -0700
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	linux-kernel@...r.kernel.org
Cc:	mingo@...e.hu, laijs@...fujitsu.com, dipankar@...ibm.com,
	akpm@...ux-foundation.org, mathieu.desnoyers@...ymtl.ca,
	josh@...htriplett.org, niv@...ibm.com, tglx@...utronix.de,
	peterz@...radead.org, rostedt@...dmis.org, dhowells@...hat.com,
	edumazet@...gle.com, darren@...art.com, fweisbec@...il.com,
	sbw@....edu, Borislav Petkov <bp@...en8.de>,
	Borislav Petkov <bp@...e.de>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 01/11] rcu: Expedite grace periods during suspend/resume

From: Borislav Petkov <bp@...en8.de>

CONFIG_RCU_FAST_NO_HZ can increase grace-period durations by up to
a factor of four, which can result in long suspend and resume times.
Thus, this commit temporarily switches to expedited grace periods when
suspending the box and return to normal settings when resuming.

[ paulmck: This also papers over an audio/irq bug, but hopefully that will
  be fixed soon. ]

Signed-off-by: Borislav Petkov <bp@...e.de>
Signed-off-by: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
---
 kernel/rcutree.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 338f1d1..69e4792 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -54,6 +54,7 @@
 #include <linux/stop_machine.h>
 #include <linux/random.h>
 #include <linux/ftrace_event.h>
+#include <linux/suspend.h>
 
 #include "rcutree.h"
 #include <trace/events/rcu.h>
@@ -3032,6 +3033,22 @@ static int rcu_cpu_notify(struct notifier_block *self,
 	return NOTIFY_OK;
 }
 
+static int 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.
  */
@@ -3273,6 +3290,7 @@ 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);
 }
-- 
1.8.1.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists