7 files changed, 76 insertions, 18 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 125e7b7f34ff..f7cb8e0758b4 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -486,12 +486,7 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 		break;
 
 	case PCI_CLASS_BRIDGE_PCI:
-		/* don't size subtractive decoding (transparent)
-		 * PCI-to-PCI bridges */
-		if (bus->self->transparent)
-			break;
 		pci_bridge_check_ranges(bus);
-		/* fall through */
 	default:
 		pbus_size_io(bus);
 		/* If the bridge supports prefetchable range, size it
diff --git a/include/linux/sched.h b/include/linux/sched.h
index fed07d03364e..6a1e7afb099b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1541,6 +1541,12 @@ static inline void idle_task_exit(void) {}
 
 extern void sched_idle_next(void);
 
+#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
+extern void wake_up_idle_cpu(int cpu);
+#else
+static inline void wake_up_idle_cpu(int cpu) { }
+#endif
+
 #ifdef CONFIG_SCHED_DEBUG
 extern unsigned int sysctl_sched_latency;
 extern unsigned int sysctl_sched_min_granularity;
diff --git a/kernel/relay.c b/kernel/relay.c
index 4c035a8a248c..d6204a485818 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -736,7 +736,7 @@ static int relay_file_open(struct inode *inode, struct file *filp)
 	kref_get(&buf->kref);
 	filp->private_data = buf;
 
-	return 0;
+	return nonseekable_open(inode, filp);
 }
 
 /**
@@ -1056,6 +1056,10 @@ static struct pipe_buf_operations relay_pipe_buf_ops = {
 	.get = generic_pipe_buf_get,
 };
 
+static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i)
+{
+}
+
 /*
  *	subbuf_splice_actor - splice up to one subbuf's worth of data
  */
@@ -1083,6 +1087,7 @@ static int subbuf_splice_actor(struct file *in,
 		.partial = partial,
 		.flags = flags,
 		.ops = &relay_pipe_buf_ops,
+		.spd_release = relay_page_release,
 	};
 
 	if (rbuf->subbufs_produced == rbuf->subbufs_consumed)
diff --git a/kernel/sched.c b/kernel/sched.c
index 28c73f07efb2..8dcdec6fe0fe 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1052,6 +1052,49 @@ static void resched_cpu(int cpu)
 	resched_task(cpu_curr(cpu));
 	spin_unlock_irqrestore(&rq->lock, flags);
 }
+
+#ifdef CONFIG_NO_HZ
+/*
+ * When add_timer_on() enqueues a timer into the timer wheel of an
+ * idle CPU then this timer might expire before the next timer event
+ * which is scheduled to wake up that CPU. In case of a completely
+ * idle system the next event might even be infinite time into the
+ * future. wake_up_idle_cpu() ensures that the CPU is woken up and
+ * leaves the inner idle loop so the newly added timer is taken into
+ * account when the CPU goes back to idle and evaluates the timer
+ * wheel for the next timer event.
+ */
+void wake_up_idle_cpu(int cpu)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	if (cpu == smp_processor_id())
+		return;
+
+	/*
+	 * This is safe, as this function is called with the timer
+	 * wheel base lock of (cpu) held. When the CPU is on the way
+	 * to idle and has not yet set rq->curr to idle then it will
+	 * be serialized on the timer wheel base lock and take the new
+	 * timer into account automatically.
+	 */
+	if (rq->curr != rq->idle)
+		return;
+
+	/*
+	 * We can set TIF_RESCHED on the idle task of the other CPU
+	 * lockless. The worst case is that the other CPU runs the
+	 * idle task through an additional NOOP schedule()
+	 */
+	set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED);
+
+	/* NEED_RESCHED must be visible before we test polling */
+	smp_mb();
+	if (!tsk_is_polling(rq->idle))
+		smp_send_reschedule(cpu);
+}
+#endif
+
 #else
 static void __resched_task(struct task_struct *p, int tif_bit)
 {
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 278534bbca95..7f60097d443a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -174,7 +174,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
 			if (watchdog)
 				del_timer(&watchdog_timer);
 			watchdog = cs;
-			init_timer_deferrable(&watchdog_timer);
+			init_timer(&watchdog_timer);
 			watchdog_timer.function = clocksource_watchdog;
 
 			/* Reset watchdog cycles */
diff --git a/kernel/timer.c b/kernel/timer.c
index 99b00a25f88b..b024106daa70 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -451,10 +451,18 @@ void add_timer_on(struct timer_list *timer, int cpu)
 	spin_lock_irqsave(&base->lock, flags);
 	timer_set_base(timer, base);
 	internal_add_timer(base, timer);
+	/*
+	 * Check whether the other CPU is idle and needs to be
+	 * triggered to reevaluate the timer wheel when nohz is
+	 * active. We are protected against the other CPU fiddling
+	 * with the timer by holding the timer base lock. This also
+	 * makes sure that a CPU on the way to idle can not evaluate
+	 * the timer wheel.
+	 */
+	wake_up_idle_cpu(cpu);
 	spin_unlock_irqrestore(&base->lock, flags);
 }
 
-
 /**
  * mod_timer - modify a timer's timeout
  * @timer: the timer to be modified
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 971271602dd0..c22d6b6f2db4 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -322,15 +322,6 @@ next_sge:
 		ctxt->direction = DMA_FROM_DEVICE;
 		clear_bit(RDMACTXT_F_READ_DONE, &ctxt->flags);
 		clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
-		if ((ch+1)->rc_discrim == 0) {
-			/*
-			 * Checked in sq_cq_reap to see if we need to
-			 * be enqueued
-			 */
-			set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
-			ctxt->next = hdr_ctxt;
-			hdr_ctxt->next = head;
-		}
 
 		/* Prepare READ WR */
 		memset(&read_wr, 0, sizeof read_wr);
@@ -348,7 +339,17 @@ next_sge:
 		rdma_set_ctxt_sge(ctxt, &sge[ch_sge_ary[ch_no].start],
 				  &sgl_offset,
 				  read_wr.num_sge);
-
+		if (((ch+1)->rc_discrim == 0) &&
+		    (read_wr.num_sge == ch_sge_ary[ch_no].count)) {
+			/*
+			 * Mark the last RDMA_READ with a bit to
+			 * indicate all RPC data has been fetched from
+			 * the client and the RPC needs to be enqueued.
+			 */
+			set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
+			ctxt->next = hdr_ctxt;
+			hdr_ctxt->next = head;
+		}
 		/* Post the read */
 		err = svc_rdma_send(xprt, &read_wr);
 		if (err) {