sched: remove 'now' use from assignments

change all 'now' timestamp uses in assignments to rq->clock.

( this is an identity transformation that causes no functionality change:
  all such new rq->clock is necessarily preceded by an update_rq_clock()
  call. )
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -788,8 +788,8 @@ static void update_curr_load(struct rq *rq, u64 now)
 	u64 start;
 
 	start = ls->load_update_start;
-	ls->load_update_start = now;
-	ls->delta_stat += now - start;
+	ls->load_update_start = rq->clock;
+	ls->delta_stat += rq->clock - start;
 	/*
 	 * Stagger updates to ls->delta_fair. Very frequent updates
 	 * can be expensive.
@@ -1979,8 +1979,8 @@ static void update_cpu_load(struct rq *this_rq)
 	exec_delta64 = ls->delta_exec + 1;
 	ls->delta_exec = 0;
 
-	sample_interval64 = now - ls->load_update_last;
-	ls->load_update_last = now;
+	sample_interval64 = this_rq->clock - ls->load_update_last;
+	ls->load_update_last = this_rq->clock;
 
 	if ((s64)sample_interval64 < (s64)TICK_NSEC)
 		sample_interval64 = TICK_NSEC;

kernel/sched_fair.c

@@ -333,7 +333,7 @@ static void update_curr(struct cfs_rq *cfs_rq, u64 now)
 	 * since the last time we changed load (this cannot
 	 * overflow on 32 bits):
 	 */
-	delta_exec = (unsigned long)(now - curr->exec_start);
+	delta_exec = (unsigned long)(rq_of(cfs_rq)->clock - curr->exec_start);
 
 	curr->delta_exec += delta_exec;
 
@@ -341,14 +341,14 @@ static void update_curr(struct cfs_rq *cfs_rq, u64 now)
 		__update_curr(cfs_rq, curr, now);
 		curr->delta_exec = 0;
 	}
-	curr->exec_start = now;
+	curr->exec_start = rq_of(cfs_rq)->clock;
 }
 
 static inline void
 update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se, u64 now)
 {
 	se->wait_start_fair = cfs_rq->fair_clock;
-	schedstat_set(se->wait_start, now);
+	schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
 }
 
 /*
@@ -421,7 +421,8 @@ __update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se, u64 now)
 {
 	unsigned long delta_fair = se->delta_fair_run;
 
-	schedstat_set(se->wait_max, max(se->wait_max, now - se->wait_start));
+	schedstat_set(se->wait_max, max(se->wait_max,
+			rq_of(cfs_rq)->clock - se->wait_start));
 
 	if (unlikely(se->load.weight != NICE_0_LOAD))
 		delta_fair = calc_weighted(delta_fair, se->load.weight,
@@ -470,7 +471,7 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se, u64 now)
 	/*
 	 * We are starting a new run period:
 	 */
-	se->exec_start = now;
+	se->exec_start = rq_of(cfs_rq)->clock;
 }
 
 /*
@@ -545,7 +546,7 @@ enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se, u64 now)
 
 #ifdef CONFIG_SCHEDSTATS
 	if (se->sleep_start) {
-		u64 delta = now - se->sleep_start;
+		u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
 
 		if ((s64)delta < 0)
 			delta = 0;
@@ -557,7 +558,7 @@ enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se, u64 now)
 		se->sum_sleep_runtime += delta;
 	}
 	if (se->block_start) {
-		u64 delta = now - se->block_start;
+		u64 delta = rq_of(cfs_rq)->clock - se->block_start;
 
 		if ((s64)delta < 0)
 			delta = 0;
@@ -599,9 +600,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
 			struct task_struct *tsk = task_of(se);
 
 			if (tsk->state & TASK_INTERRUPTIBLE)
-				se->sleep_start = now;
+				se->sleep_start = rq_of(cfs_rq)->clock;
 			if (tsk->state & TASK_UNINTERRUPTIBLE)
-				se->block_start = now;
+				se->block_start = rq_of(cfs_rq)->clock;
 		}
 		cfs_rq->wait_runtime -= se->wait_runtime;
 #endif

kernel/sched_rt.c

@@ -15,14 +15,14 @@ static inline void update_curr_rt(struct rq *rq, u64 now)
 	if (!task_has_rt_policy(curr))
 		return;
 
-	delta_exec = now - curr->se.exec_start;
+	delta_exec = rq->clock - curr->se.exec_start;
 	if (unlikely((s64)delta_exec < 0))
 		delta_exec = 0;
 
 	schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec));
 
 	curr->se.sum_exec_runtime += delta_exec;
-	curr->se.exec_start = now;
+	curr->se.exec_start = rq->clock;
 }
 
 static void
@@ -89,7 +89,7 @@ static struct task_struct *pick_next_task_rt(struct rq *rq, u64 now)
 	queue = array->queue + idx;
 	next = list_entry(queue->next, struct task_struct, run_list);
 
-	next->se.exec_start = now;
+	next->se.exec_start = rq->clock;
 
 	return next;
 }