From 2d8f8176515f2516b9a0b85642a7b842eb53552b Mon Sep 17 00:00:00 2001
From: Jonathan Herman <hermanjl@cs.unc.edu>
Date: Sun, 13 May 2012 16:15:33 -0400
Subject: Can disable nonpreemptivity

---
 include/litmus/litmus.h | 18 ++++++++++++++++--
 litmus/Kconfig          |  2 --
 litmus/dgl.c            |  4 ++++
 litmus/sched_color.c    | 22 +++++++++++++++++-----
 4 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/include/litmus/litmus.h b/include/litmus/litmus.h
index f0ddb89e68dd..9fcf1f45820f 100644
--- a/include/litmus/litmus.h
+++ b/include/litmus/litmus.h
@@ -169,7 +169,7 @@ static inline void request_exit_np(struct task_struct *t)
 
 static inline void make_np(struct task_struct *t)
 {
-	tsk_rt(t)->kernel_np++;
+	tsk_rt(t)->kernel_np = 1;
 }
 
 /* Caller should check if preemption is necessary when
@@ -177,7 +177,7 @@ static inline void make_np(struct task_struct *t)
  */
 static inline int take_np(struct task_struct *t)
 {
-	return --tsk_rt(t)->kernel_np;
+	return tsk_rt(t)->kernel_np = 0;
 }
 
 /* returns 0 if remote CPU needs an IPI to preempt, 1 if no IPI is required */
@@ -210,6 +210,20 @@ static inline int request_exit_np_atomic(struct task_struct *t)
 
 #else
 
+
+static inline void make_np(struct task_struct *t)
+{
+
+}
+
+/* Caller should check if preemption is necessary when
+ * the function return 0.
+ */
+static inline int take_np(struct task_struct *t)
+{
+	return 0;
+}
+
 static inline int is_kernel_np(struct task_struct* t)
 {
 	return 0;
diff --git a/litmus/Kconfig b/litmus/Kconfig
index 272b64c30ba3..f0c48a6a3efb 100644
--- a/litmus/Kconfig
+++ b/litmus/Kconfig
@@ -14,7 +14,6 @@ config PLUGIN_CEDF
 
 config PLUGIN_COLOR
         bool "Scheduling with Colors"
-	depends on NP_SECTION
         default y
         help
           Include the scheduling with colors scheduler.
@@ -65,7 +64,6 @@ config NP_SECTION
 
 config LITMUS_LOCKING
         bool "Support for real-time locking protocols"
-	depends on NP_SECTION
 	default n
 	help
 	  Enable LITMUS^RT's deterministic multiprocessor real-time
diff --git a/litmus/dgl.c b/litmus/dgl.c
index 2df27b48fcdf..0c1ce73868e3 100644
--- a/litmus/dgl.c
+++ b/litmus/dgl.c
@@ -126,6 +126,10 @@ void set_req(struct dgl *dgl, struct dgl_group_req *greq,
 
 	BUG_ON(replicas > dgl->num_replicas);
 
+#ifndef CONFIG_NP_SECTION
+	BUG_ON(1);
+#endif
+
 	mask_idx(resource, &word, &bit);
 	__set_bit(bit, &greq->requested[word]);
 
diff --git a/litmus/sched_color.c b/litmus/sched_color.c
index 29b2be97da52..8554fde49c0b 100644
--- a/litmus/sched_color.c
+++ b/litmus/sched_color.c
@@ -57,11 +57,19 @@ static raw_spinlock_t dgl_lock;
 #define task_fserver(task)     (&task_entry(task)->fifo_server.server)
 #define entry_lock(entry)      (&entry->rm_domain.ready_lock)
 
-#define has_resources(t, c)    (tsk_rt(t)->req == group_lock.acquired[c])
+
 #define task_dom(entry, task)  (is_be(task) ? &fifo_domain : &entry->rm_domain)
 #define task_lock(entry, task) (is_be(task) ? &fifo_lock   : entry_lock(entry))
 #define is_fifo_server(s)      (s->sid > num_online_cpus())
 
+#ifdef CONFIG_NP_SECTION
+#define has_resources(t, c)    (tsk_rt(t)->req == group_lock.acquired[c])
+#else
+#define has_resources(t, c)   (1)
+#endif
+
+
+
 /*
  * Requeue onto domain's release or ready queue based on task state.
  */
@@ -90,6 +98,7 @@ static void requeue(rt_domain_t *dom, struct task_struct* t)
 static void release_resources(struct task_struct *t)
 {
 	struct task_struct *sched;
+#ifdef CONFIG_NP_SECTION
 
 	TRACE_TASK(t, "Releasing resources\n");
 
@@ -99,7 +108,8 @@ static void release_resources(struct task_struct *t)
 			release_resources(sched);
 	} else if (is_kernel_np(t))
 		remove_group_req(&group_lock, tsk_rt(t)->req);
-	tsk_rt(t)->kernel_np = 0;
+	take_np(t);
+#endif
 }
 
 /*
@@ -112,6 +122,7 @@ static void acquire_resources(struct task_struct *t)
 	struct rt_server *server;
 	struct task_struct *sched;
 
+#ifdef CONFIG_NP_SECTION
 	/* Can't acquire resources if t is not running */
 	BUG_ON(!get_task_server(t));
 
@@ -134,17 +145,18 @@ static void acquire_resources(struct task_struct *t)
 		/* Become np if there is a running task */
 		if (sched && has_resources(sched, cpu)) {
 			TRACE_TASK(t, "Running task with resource\n");
-			tsk_rt(t)->kernel_np = 1;
+			make_np(t);
 		} else {
 			TRACE_TASK(t, "Running no resources\n");
-			tsk_rt(t)->kernel_np = 0;
+			take_np(t);
 		}
 	} else {
 		TRACE_TASK(t, "Acquiring resources\n");
 		if (!has_resources(t, cpu))
 			add_group_req(&group_lock, tsk_rt(t)->req, cpu);
-		tsk_rt(t)->kernel_np = 1;
+		make_np(t);
 	}
+#endif
 }
 
 /*
-- 
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