From 48e1a7b1cb8664118f843ab32350eb61ba7aac78 Mon Sep 17 00:00:00 2001
From: Suresh Siddha <suresh.b.siddha@intel.com>
Date: Thu, 30 Sep 2010 21:19:07 -0400
Subject: [PATCH] --- yaml --- r: 211175 b: refs/heads/master c:
 6110a1f43c27b516e16d5ce8860fca50748c2a87 h: refs/heads/master i:   211173:
 e34f4f757a5b26fd793769026a326da8d66e1ac8   211171:
 e32fa28ea184fcf8096232edb6f4fb95f8d425d3   211167:
 00f1fefef99ec3bad671d2508990dace0957c9d5 v: v3

---
 [refs]                          |  2 +-
 trunk/drivers/idle/intel_idle.c | 18 ++++++++++++++----
 trunk/include/linux/cpuidle.h   |  1 +
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 5e48c0ab893a..9a7248b60ad8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9587a678fa56ea6d7f39b048f24f5d03a89bf9b3
+refs/heads/master: 6110a1f43c27b516e16d5ce8860fca50748c2a87
diff --git a/trunk/drivers/idle/intel_idle.c b/trunk/drivers/idle/intel_idle.c
index 96bf38097996..0906fc5b69b9 100644
--- a/trunk/drivers/idle/intel_idle.c
+++ b/trunk/drivers/idle/intel_idle.c
@@ -108,7 +108,7 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = {
 		.name = "NHM-C3",
 		.desc = "MWAIT 0x10",
 		.driver_data = (void *) 0x10,
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 20,
 		.power_usage = 500,
 		.target_residency = 80,
@@ -117,7 +117,7 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = {
 		.name = "NHM-C6",
 		.desc = "MWAIT 0x20",
 		.driver_data = (void *) 0x20,
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 200,
 		.power_usage = 350,
 		.target_residency = 800,
@@ -149,7 +149,7 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
 		.name = "ATM-C4",
 		.desc = "MWAIT 0x30",
 		.driver_data = (void *) 0x30,
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 100,
 		.power_usage = 250,
 		.target_residency = 400,
@@ -159,7 +159,7 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
 		.name = "ATM-C6",
 		.desc = "MWAIT 0x40",
 		.driver_data = (void *) 0x40,
-		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
 		.exit_latency = 200,
 		.power_usage = 150,
 		.target_residency = 800,
@@ -185,6 +185,16 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state)
 
 	local_irq_disable();
 
+	/*
+	 * If the state flag indicates that the TLB will be flushed or if this
+	 * is the deepest c-state supported, do a voluntary leave mm to avoid
+	 * costly and mostly unnecessary wakeups for flushing the user TLB's
+	 * associated with the active mm.
+	 */
+	if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED ||
+	    (&dev->states[dev->state_count - 1] == state))
+		leave_mm(cpu);
+
 	if (!(lapic_timer_reliable_states & (1 << (cstate))))
 		clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
 
diff --git a/trunk/include/linux/cpuidle.h b/trunk/include/linux/cpuidle.h
index 36ca9721a0c2..1be416bbbb82 100644
--- a/trunk/include/linux/cpuidle.h
+++ b/trunk/include/linux/cpuidle.h
@@ -53,6 +53,7 @@ struct cpuidle_state {
 #define CPUIDLE_FLAG_BALANCED	(0x40) /* medium latency, moderate savings */
 #define CPUIDLE_FLAG_DEEP	(0x80) /* high latency, large savings */
 #define CPUIDLE_FLAG_IGNORE	(0x100) /* ignore during this idle period */
+#define CPUIDLE_FLAG_TLB_FLUSHED (0x200) /* tlb will be flushed */
 
 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)