This patch groups together fields used by CFS (for SCHED_NORMAL tasks) 
in task_struct and runqueue into separate structures so that they can be 
reused in a later patch.

'struct sched_entity' represents the attributes used by CFS for every
schedulable entity (task in this case).

'struct lrq' represents the runqueue used to store schedulable entities (tasks 
in this case) and to maintain various clocks (ex: fair clock for tasks).

This patch also modifies rest of kernel to reflect these new structures.

Intended effect of this patch is zero on overall functionality of
scheduler.

Signed-off-by : Srivatsa Vaddagiri <vatsa@in.ibm.com>

---
 fs/proc/array.c           |    2 
 include/linux/sched.h     |   44 ++++----
 kernel/exit.c             |    2 
 kernel/posix-cpu-timers.c |   19 +--
 kernel/sched.c            |  195 +++++++++++++++++++------------------
 kernel/sched_debug.c      |   85 ++++++++--------
 kernel/sched_fair.c       |  238 +++++++++++++++++++++++-----------------------
 7 files changed, 301 insertions(+), 284 deletions(-)

Index: linux-2.6.21-rc7/fs/proc/array.c
===================================================================
--- linux-2.6.21-rc7.orig/fs/proc/array.c	2007-05-23 20:46:40.000000000 +0530
+++ linux-2.6.21-rc7/fs/proc/array.c	2007-05-23 20:48:34.000000000 +0530
@@ -412,7 +412,7 @@
 	 * Use CFS's precise accounting, if available:
 	 */
 	if (!has_rt_policy(task)) {
-		utime = nsec_to_clock_t(task->sum_exec_runtime);
+		utime = nsec_to_clock_t(task->se.sum_exec_runtime);
 		stime = 0;
 	}
 
Index: linux-2.6.21-rc7/include/linux/sched.h
===================================================================
--- linux-2.6.21-rc7.orig/include/linux/sched.h	2007-05-23 20:46:40.000000000 +0530
+++ linux-2.6.21-rc7/include/linux/sched.h	2007-05-23 20:48:34.000000000 +0530
@@ -838,6 +838,29 @@
 	void (*task_new) (struct rq *rq, struct task_struct *p);
 };
 
+/* CFS scheduling entity (task, user etc) statistics fields: */
+struct sched_entity {
+	int load_weight;	/* for niceness load balancing purposes */
+	int on_rq;
+	struct rb_node run_node;
+	u64 wait_start_fair;
+	u64 wait_start;
+	u64 exec_start;
+	u64 sleep_start, sleep_start_fair;
+	u64 block_start;
+	u64 sleep_max;
+	u64 block_max;
+	u64 exec_max;
+	u64 wait_max;
+	u64 last_ran;
+
+	s64 wait_runtime;
+	u64 sum_exec_runtime;
+	s64 fair_key;
+	s64 sum_wait_runtime, sum_sleep_runtime;
+	unsigned long wait_runtime_overruns, wait_runtime_underruns;
+};
+
 struct task_struct {
 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
 	void *stack;
@@ -852,34 +875,15 @@
 	int oncpu;
 #endif
 #endif
-	int load_weight;	/* for niceness load balancing purposes */
 
 	int prio, static_prio, normal_prio;
-	int on_rq;
 	struct list_head run_list;
-	struct rb_node run_node;
+	struct sched_entity se;
 
 	unsigned short ioprio;
 #ifdef CONFIG_BLK_DEV_IO_TRACE
 	unsigned int btrace_seq;
 #endif
-	/* CFS scheduling class statistics fields: */
-	u64 wait_start_fair;
-	u64 wait_start;
-	u64 exec_start;
-	u64 sleep_start, sleep_start_fair;
-	u64 block_start;
-	u64 sleep_max;
-	u64 block_max;
-	u64 exec_max;
-	u64 wait_max;
-	u64 last_ran;
-
-	s64 wait_runtime;
-	u64 sum_exec_runtime;
-	s64 fair_key;
-	s64 sum_wait_runtime, sum_sleep_runtime;
-	unsigned long wait_runtime_overruns, wait_runtime_underruns;
 
 	unsigned int policy;
 	cpumask_t cpus_allowed;
Index: linux-2.6.21-rc7/kernel/exit.c
===================================================================
--- linux-2.6.21-rc7.orig/kernel/exit.c	2007-05-23 20:46:40.000000000 +0530
+++ linux-2.6.21-rc7/kernel/exit.c	2007-05-23 20:48:34.000000000 +0530
@@ -124,7 +124,7 @@
 		sig->nivcsw += tsk->nivcsw;
 		sig->inblock += task_io_get_inblock(tsk);
 		sig->oublock += task_io_get_oublock(tsk);
-		sig->sum_sched_runtime += tsk->sum_exec_runtime;
+		sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
 		sig = NULL; /* Marker for below. */
 	}
 
Index: linux-2.6.21-rc7/kernel/posix-cpu-timers.c
===================================================================
--- linux-2.6.21-rc7.orig/kernel/posix-cpu-timers.c	2007-05-23 20:46:40.000000000 +0530
+++ linux-2.6.21-rc7/kernel/posix-cpu-timers.c	2007-05-23 20:48:34.000000000 +0530
@@ -161,7 +161,8 @@
 }
 static inline unsigned long long sched_ns(struct task_struct *p)
 {
-	return (p == current) ? current_sched_runtime(p) : p->sum_exec_runtime;
+	return (p == current) ? current_sched_runtime(p) :
+				 p->se.sum_exec_runtime;
 }
 
 int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
@@ -249,7 +250,7 @@
 		cpu->sched = p->signal->sum_sched_runtime;
 		/* Add in each other live thread.  */
 		while ((t = next_thread(t)) != p) {
-			cpu->sched += t->sum_exec_runtime;
+			cpu->sched += t->se.sum_exec_runtime;
 		}
 		cpu->sched += sched_ns(p);
 		break;
@@ -467,7 +468,7 @@
 void posix_cpu_timers_exit(struct task_struct *tsk)
 {
 	cleanup_timers(tsk->cpu_timers,
-		       tsk->utime, tsk->stime, tsk->sum_exec_runtime);
+		       tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
 
 }
 void posix_cpu_timers_exit_group(struct task_struct *tsk)
@@ -475,7 +476,7 @@
 	cleanup_timers(tsk->signal->cpu_timers,
 		       cputime_add(tsk->utime, tsk->signal->utime),
 		       cputime_add(tsk->stime, tsk->signal->stime),
-		       tsk->sum_exec_runtime + tsk->signal->sum_sched_runtime);
+		     tsk->se.sum_exec_runtime + tsk->signal->sum_sched_runtime);
 }
 
 
@@ -536,7 +537,7 @@
 		nsleft = max_t(unsigned long long, nsleft, 1);
 		do {
 			if (likely(!(t->flags & PF_EXITING))) {
-				ns = t->sum_exec_runtime + nsleft;
+				ns = t->se.sum_exec_runtime + nsleft;
 				if (t->it_sched_expires == 0 ||
 				    t->it_sched_expires > ns) {
 					t->it_sched_expires = ns;
@@ -1004,7 +1005,7 @@
 		struct cpu_timer_list *t = list_first_entry(timers,
 						      struct cpu_timer_list,
 						      entry);
-		if (!--maxfire || tsk->sum_exec_runtime < t->expires.sched) {
+		if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {
 			tsk->it_sched_expires = t->expires.sched;
 			break;
 		}
@@ -1049,7 +1050,7 @@
 	do {
 		utime = cputime_add(utime, t->utime);
 		stime = cputime_add(stime, t->stime);
-		sum_sched_runtime += t->sum_exec_runtime;
+		sum_sched_runtime += t->se.sum_exec_runtime;
 		t = next_thread(t);
 	} while (t != tsk);
 	ptime = cputime_add(utime, stime);
@@ -1208,7 +1209,7 @@
 				t->it_virt_expires = ticks;
 			}
 
-			sched = t->sum_exec_runtime + sched_left;
+			sched = t->se.sum_exec_runtime + sched_left;
 			if (sched_expires && (t->it_sched_expires == 0 ||
 					      t->it_sched_expires > sched)) {
 				t->it_sched_expires = sched;
@@ -1300,7 +1301,7 @@
 
 	if (UNEXPIRED(prof) && UNEXPIRED(virt) &&
 	    (tsk->it_sched_expires == 0 ||
-	     tsk->sum_exec_runtime < tsk->it_sched_expires))
+	     tsk->se.sum_exec_runtime < tsk->it_sched_expires))
 		return;
 
 #undef	UNEXPIRED
Index: linux-2.6.21-rc7/kernel/sched.c
===================================================================
--- linux-2.6.21-rc7.orig/kernel/sched.c	2007-05-23 20:48:26.000000000 +0530
+++ linux-2.6.21-rc7/kernel/sched.c	2007-05-23 20:48:34.000000000 +0530
@@ -114,6 +114,23 @@
 	struct list_head queue[MAX_RT_PRIO];
 };
 
+/* CFS-related fields in a runqueue */
+struct lrq {
+	unsigned long raw_weighted_load;
+	#define CPU_LOAD_IDX_MAX 5
+	unsigned long cpu_load[CPU_LOAD_IDX_MAX];
+	unsigned long nr_load_updates;
+
+	u64 fair_clock, prev_fair_clock;
+	u64 exec_clock, prev_exec_clock;
+	s64 wait_runtime;
+	unsigned long wait_runtime_overruns, wait_runtime_underruns;
+
+	struct rb_root tasks_timeline;
+	struct rb_node *rb_leftmost;
+	struct rb_node *rb_load_balance_curr;
+};
+
 /*
  * This is the main, per-CPU runqueue data structure.
  *
@@ -129,16 +146,13 @@
 	 * remote CPUs use both these fields when doing load calculation.
 	 */
 	long nr_running;
-	unsigned long raw_weighted_load;
-	#define CPU_LOAD_IDX_MAX 5
-	unsigned long cpu_load[CPU_LOAD_IDX_MAX];
+	struct lrq lrq;
 
 	unsigned char idle_at_tick;
 #ifdef CONFIG_NO_HZ
 	unsigned char in_nohz_recently;
 #endif
 	u64 nr_switches;
-	unsigned long nr_load_updates;
 
 	/*
 	 * This is part of a global counter where only the total sum
@@ -154,10 +168,6 @@
 
 	u64 clock, prev_clock_raw;
 	s64 clock_max_delta;
-	u64 fair_clock, prev_fair_clock;
-	u64 exec_clock, prev_exec_clock;
-	s64 wait_runtime;
-	unsigned long wait_runtime_overruns, wait_runtime_underruns;
 
 	unsigned int clock_warps;
 	unsigned int clock_unstable_events;
@@ -168,10 +178,6 @@
 	int rt_load_balance_idx;
 	struct list_head *rt_load_balance_head, *rt_load_balance_curr;
 
-	struct rb_root tasks_timeline;
-	struct rb_node *rb_leftmost;
-	struct rb_node *rb_load_balance_curr;
-
 	atomic_t nr_iowait;
 
 #ifdef CONFIG_SMP
@@ -573,13 +579,13 @@
 static inline void
 inc_raw_weighted_load(struct rq *rq, const struct task_struct *p)
 {
-	rq->raw_weighted_load += p->load_weight;
+	rq->lrq.raw_weighted_load += p->se.load_weight;
 }
 
 static inline void
 dec_raw_weighted_load(struct rq *rq, const struct task_struct *p)
 {
-	rq->raw_weighted_load -= p->load_weight;
+	rq->lrq.raw_weighted_load -= p->se.load_weight;
 }
 
 static inline void inc_nr_running(struct task_struct *p, struct rq *rq)
@@ -605,22 +611,22 @@
 
 static void set_load_weight(struct task_struct *p)
 {
-	task_rq(p)->wait_runtime -= p->wait_runtime;
-	p->wait_runtime = 0;
+	task_rq(p)->lrq.wait_runtime -= p->se.wait_runtime;
+	p->se.wait_runtime = 0;
 
 	if (has_rt_policy(p)) {
-		p->load_weight = prio_to_weight[0] * 2;
+		p->se.load_weight = prio_to_weight[0] * 2;
 		return;
 	}
 	/*
 	 * SCHED_BATCH tasks get minimal weight:
 	 */
 	if (p->policy == SCHED_BATCH) {
-		p->lo