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.
        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;
 
         * 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;
 
                __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);
 }
 
 /*
 {
        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,
        /*
         * We are starting a new run period:
         */
-       se->exec_start = now;
+       se->exec_start = rq_of(cfs_rq)->clock;
 }
 
 /*
 
 #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;
                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;
                        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
 
        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
        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;
 }