sched/alt: Fix BMQ bugs

Two bugs cause torvalds#89 issue,
* Unable to deboost task when time slice expired.
* New forked task is running at MAX_PRIORITY_ADJ.

kernel/sched/bmq.h

@@ -71,14 +71,16 @@ inline int task_running_nice(struct task_struct *p)
 }
 
 static inline void sched_update_rq_clock(struct rq *rq) {}
-static inline void sched_task_renew(struct task_struct *p, const struct rq *rq) {}
-static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) {}
 
-static void sched_task_fork(struct task_struct *p, struct rq *rq)
+static inline void sched_task_renew(struct task_struct *p, const struct rq *rq)
 {
-	p->boost_prio = MAX_PRIORITY_ADJ;
+	if (rq_switch_time(rq) > sysctl_sched_base_slice)
+		deboost_task(p);
 }
 
+static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) {}
+static void sched_task_fork(struct task_struct *p, struct rq *rq) {}
+
 static inline void do_sched_yield_type_1(struct task_struct *p, struct rq *rq)
 {
 	p->boost_prio = MAX_PRIORITY_ADJ;
@@ -92,10 +94,6 @@ static inline void sched_task_ttwu(struct task_struct *p)
 
 static inline void sched_task_deactivate(struct task_struct *p, struct rq *rq)
 {
-	u64 switch_ns = rq_switch_time(rq);
-
-	if (switch_ns < boost_threshold(p))
+	if (rq_switch_time(rq) < boost_threshold(p))
 		boost_task(p);
-	else if (switch_ns > sysctl_sched_base_slice)
-		deboost_task(p);
 }