sched: remove wait_runtime fields and features

remove wait_runtime based fields and features, now that the CFS
math has been changed over to the vruntime metric.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 14 insertions, 152 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 21cc3b2be023..0f0cf374c775 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -176,11 +176,8 @@ struct cfs_rq {
         struct load_weight load;
         unsigned long nr_running;
 
-        s64 fair_clock;
         u64 exec_clock;
         u64 min_vruntime;
-        s64 wait_runtime;
-        unsigned long wait_runtime_overruns, wait_runtime_underruns;
 
         struct rb_root tasks_timeline;
         struct rb_node *rb_leftmost;
@@ -389,20 +386,14 @@ static void update_rq_clock(struct rq *rq)
  * Debugging: various feature bits
  */
 enum {
-        SCHED_FEAT_FAIR_SLEEPERS        = 1,
-        SCHED_FEAT_NEW_FAIR_SLEEPERS    = 2,
-        SCHED_FEAT_SLEEPER_AVG          = 4,
-        SCHED_FEAT_SLEEPER_LOAD_AVG     = 8,
-        SCHED_FEAT_START_DEBIT          = 16,
-        SCHED_FEAT_USE_TREE_AVG         = 32,
-        SCHED_FEAT_APPROX_AVG           = 64,
+        SCHED_FEAT_NEW_FAIR_SLEEPERS    = 1,
+        SCHED_FEAT_START_DEBIT          = 2,
+        SCHED_FEAT_USE_TREE_AVG         = 4,
+        SCHED_FEAT_APPROX_AVG           = 8,
 };
 
 const_debug unsigned int sysctl_sched_features =
-                SCHED_FEAT_FAIR_SLEEPERS        *0 |
                 SCHED_FEAT_NEW_FAIR_SLEEPERS    *1 |
-                SCHED_FEAT_SLEEPER_AVG          *0 |
-                SCHED_FEAT_SLEEPER_LOAD_AVG     *1 |
                 SCHED_FEAT_START_DEBIT          *1 |
                 SCHED_FEAT_USE_TREE_AVG         *0 |
                 SCHED_FEAT_APPROX_AVG           *0;
@@ -716,15 +707,11 @@ calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
 static inline void update_load_add(struct load_weight *lw, unsigned long inc)
 {
         lw->weight += inc;
-        if (sched_feat(FAIR_SLEEPERS))
-                lw->inv_weight = WMULT_CONST / lw->weight;
 }
 
 static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
 {
         lw->weight -= dec;
-        if (sched_feat(FAIR_SLEEPERS) && likely(lw->weight))
-                lw->inv_weight = WMULT_CONST / lw->weight;
 }
 
 /*
@@ -848,8 +835,6 @@ static void dec_nr_running(struct task_struct *p, struct rq *rq)
 
 static void set_load_weight(struct task_struct *p)
 {
-        p->se.wait_runtime = 0;
-
         if (task_has_rt_policy(p)) {
                 p->se.load.weight = prio_to_weight[0] * 2;
                 p->se.load.inv_weight = prio_to_wmult[0] >> 1;
@@ -995,13 +980,9 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 {
         int old_cpu = task_cpu(p);
         struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu);
-        u64 clock_offset, fair_clock_offset;
+        u64 clock_offset;
 
         clock_offset = old_rq->clock - new_rq->clock;
-        fair_clock_offset = old_rq->cfs.fair_clock - new_rq->cfs.fair_clock;
-
-        if (p->se.wait_start_fair)
-                p->se.wait_start_fair -= fair_clock_offset;
 
 #ifdef CONFIG_SCHEDSTATS
         if (p->se.wait_start)
@@ -1571,15 +1552,12 @@ int fastcall wake_up_state(struct task_struct *p, unsigned int state)
  */
 static void __sched_fork(struct task_struct *p)
 {
-        p->se.wait_start_fair           = 0;
         p->se.exec_start                = 0;
         p->se.sum_exec_runtime          = 0;
         p->se.prev_sum_exec_runtime     = 0;
-        p->se.wait_runtime              = 0;
 
 #ifdef CONFIG_SCHEDSTATS
         p->se.wait_start                = 0;
-        p->se.sum_wait_runtime          = 0;
         p->se.sum_sleep_runtime         = 0;
         p->se.sleep_start               = 0;
         p->se.block_start               = 0;
@@ -1588,8 +1566,6 @@ static void __sched_fork(struct task_struct *p)
         p->se.exec_max                  = 0;
         p->se.slice_max                 = 0;
         p->se.wait_max                  = 0;
-        p->se.wait_runtime_overruns     = 0;
-        p->se.wait_runtime_underruns    = 0;
 #endif
 
         INIT_LIST_HEAD(&p->run_list);
@@ -6436,7 +6412,6 @@ int in_sched_functions(unsigned long addr)
 static inline void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq)
 {
         cfs_rq->tasks_timeline = RB_ROOT;
-        cfs_rq->fair_clock = 1;
 #ifdef CONFIG_FAIR_GROUP_SCHED
         cfs_rq->rq = rq;
 #endif
@@ -6562,15 +6537,12 @@ void normalize_rt_tasks(void)
         read_lock_irq(&tasklist_lock);
         do_each_thread(g, p) {
                 p->se.fair_key                  = 0;
-                p->se.wait_runtime              = 0;
                 p->se.exec_start                = 0;
-                p->se.wait_start_fair           = 0;
 #ifdef CONFIG_SCHEDSTATS
                 p->se.wait_start                = 0;
                 p->se.sleep_start               = 0;
                 p->se.block_start               = 0;
 #endif
-                task_rq(p)->cfs.fair_clock      = 0;
                 task_rq(p)->clock               = 0;
 
                 if (!rt_task(p)) {
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 3350169a7d2a..e3b62324ac31 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -36,21 +36,16 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
         else
                 SEQ_printf(m, " ");
 
-        SEQ_printf(m, "%15s %5d %15Ld %13Ld %13Ld %9Ld %5d ",
+        SEQ_printf(m, "%15s %5d %15Ld %13Ld %5d ",
                 p->comm, p->pid,
                 (long long)p->se.fair_key,
-                (long long)(p->se.fair_key - rq->cfs.fair_clock),
-                (long long)p->se.wait_runtime,
                 (long long)(p->nvcsw + p->nivcsw),
                 p->prio);
 #ifdef CONFIG_SCHEDSTATS
-        SEQ_printf(m, "%15Ld %15Ld %15Ld %15Ld %15Ld %15Ld\n",
+        SEQ_printf(m, "%15Ld %15Ld %15Ld\n",
                 (long long)p->se.vruntime,
                 (long long)p->se.sum_exec_runtime,
-                (long long)p->se.sum_wait_runtime,
-                (long long)p->se.sum_sleep_runtime,
-                (long long)p->se.wait_runtime_overruns,
-                (long long)p->se.wait_runtime_underruns);
+                (long long)p->se.sum_sleep_runtime);
 #else
         SEQ_printf(m, "%15Ld %15Ld %15Ld %15Ld %15Ld\n",
                 0LL, 0LL, 0LL, 0LL, 0LL);
@@ -63,10 +58,8 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
 
         SEQ_printf(m,
         "\nrunnable tasks:\n"
-        "            task   PID        tree-key         delta       waiting"
-        "  switches  prio"
-        "    exec-runtime        sum-exec        sum-wait       sum-sleep"
-        "    wait-overrun   wait-underrun\n"
+        "            task   PID        tree-key  switches  prio"
+        "    exec-runtime        sum-exec       sum-sleep\n"
         "------------------------------------------------------------------"
         "--------------------------------"
         "------------------------------------------------"
@@ -84,29 +77,6 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
         read_unlock_irq(&tasklist_lock);
 }
 
-static void
-print_cfs_rq_runtime_sum(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
-{
-        s64 wait_runtime_rq_sum = 0;
-        struct task_struct *p;
-        struct rb_node *curr;
-        unsigned long flags;
-        struct rq *rq = &per_cpu(runqueues, cpu);
-
-        spin_lock_irqsave(&rq->lock, flags);
-        curr = first_fair(cfs_rq);
-        while (curr) {
-                p = rb_entry(curr, struct task_struct, se.run_node);
-                wait_runtime_rq_sum += p->se.wait_runtime;
-
-                curr = rb_next(curr);
-        }
-        spin_unlock_irqrestore(&rq->lock, flags);
-
-        SEQ_printf(m, "  .%-30s: %Ld\n", "wait_runtime_rq_sum",
-                (long long)wait_runtime_rq_sum);
-}
-
 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 {
         s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
@@ -120,7 +90,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 #define P(x) \
         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(cfs_rq->x))
 
-        P(fair_clock);
         P(exec_clock);
 
         spin_lock_irqsave(&rq->lock, flags);
@@ -144,13 +113,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
         spread0 = min_vruntime - rq0_min_vruntime;
         SEQ_printf(m, "  .%-30s: %Ld\n", "spread0",
                         (long long)spread0);
-
-        P(wait_runtime);
-        P(wait_runtime_overruns);
-        P(wait_runtime_underruns);
 #undef P
-
-        print_cfs_rq_runtime_sum(m, cpu, cfs_rq);
 }
 
 static void print_cpu(struct seq_file *m, int cpu)
@@ -268,8 +231,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 #define P(F) \
         SEQ_printf(m, "%-25s:%20Ld\n", #F, (long long)p->F)
 
-        P(se.wait_runtime);
-        P(se.wait_start_fair);
         P(se.exec_start);
         P(se.vruntime);
         P(se.sum_exec_runtime);
@@ -283,9 +244,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
         P(se.exec_max);
         P(se.slice_max);
         P(se.wait_max);
-        P(se.wait_runtime_overruns);
-        P(se.wait_runtime_underruns);
-        P(se.sum_wait_runtime);
 #endif
         SEQ_printf(m, "%-25s:%20Ld\n",
                    "nr_switches", (long long)(p->nvcsw + p->nivcsw));
@@ -312,8 +270,6 @@ void proc_sched_set_task(struct task_struct *p)
         p->se.exec_max                  = 0;
         p->se.slice_max                 = 0;
         p->se.wait_max                  = 0;
-        p->se.wait_runtime_overruns     = 0;
-        p->se.wait_runtime_underruns    = 0;
 #endif
         p->se.sum_exec_runtime          = 0;
         p->se.prev_sum_exec_runtime     = 0;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index a94189c42d1a..2df5a6467812 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -178,8 +178,6 @@ __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
         update_load_add(&cfs_rq->load, se->load.weight);
         cfs_rq->nr_running++;
         se->on_rq = 1;
-
-        schedstat_add(cfs_rq, wait_runtime, se->wait_runtime);
 }
 
 static void
@@ -192,8 +190,6 @@ __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
         update_load_sub(&cfs_rq->load, se->load.weight);
         cfs_rq->nr_running--;
         se->on_rq = 0;
-
-        schedstat_add(cfs_rq, wait_runtime, -se->wait_runtime);
 }
 
 static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq)
@@ -249,13 +245,6 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
         return period;
 }
 
-static void
-add_wait_runtime(struct cfs_rq *cfs_rq, struct sched_entity *se, long delta)
-{
-        se->wait_runtime += delta;
-        schedstat_add(cfs_rq, wait_runtime, delta);
-}
-
 /*
  * Update the current task's runtime statistics. Skip current tasks that
  * are not in our scheduling class.
@@ -264,9 +253,7 @@ static inline void
 __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
               unsigned long delta_exec)
 {
-        unsigned long delta_fair, delta_mine, delta_exec_weighted;
-        struct load_weight *lw = &cfs_rq->load;
-        unsigned long load = lw->weight;
+        unsigned long delta_exec_weighted;
 
         schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
 
@@ -278,25 +265,6 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
                                                         &curr->load);
         }
         curr->vruntime += delta_exec_weighted;
-
-        if (!sched_feat(FAIR_SLEEPERS))
-                return;
-
-        if (unlikely(!load))
-                return;
-
-        delta_fair = calc_delta_fair(delta_exec, lw);
-        delta_mine = calc_delta_mine(delta_exec, curr->load.weight, lw);
-
-        cfs_rq->fair_clock += delta_fair;
-        /*
-         * We executed delta_exec amount of time on the CPU,
-         * but we were only entitled to delta_mine amount of
-         * time during that period (if nr_running == 1 then
-         * the two values are equal)
-         * [Note: delta_mine - delta_exec is negative]:
-         */
-        add_wait_runtime(cfs_rq, curr, delta_mine - delta_exec);
 }
 
 static void update_curr(struct cfs_rq *cfs_rq)
@@ -322,7 +290,6 @@ static void update_curr(struct cfs_rq *cfs_rq)
 static inline void
 update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        se->wait_start_fair = cfs_rq->fair_clock;
         schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
 }
 
@@ -354,35 +321,11 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
         se->fair_key = se->vruntime;
 }
 
-/*
- * Note: must be called with a freshly updated rq->fair_clock.
- */
-static inline void
-__update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se,
-                        unsigned long delta_fair)
-{
-        schedstat_set(se->wait_max, max(se->wait_max,
-                        rq_of(cfs_rq)->clock - se->wait_start));
-
-        delta_fair = calc_weighted(delta_fair, se);
-
-        add_wait_runtime(cfs_rq, se, delta_fair);
-}
-
 static void
 update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        unsigned long delta_fair;
-
-        if (unlikely(!se->wait_start_fair))
-                return;
-
-        delta_fair = (unsigned long)min((u64)(2*sysctl_sched_runtime_limit),
-                        (u64)(cfs_rq->fair_clock - se->wait_start_fair));
-
-        __update_stats_wait_end(cfs_rq, se, delta_fair);
-
-        se->wait_start_fair = 0;
+        schedstat_set(se->wait_max, max(se->wait_max,
+                        rq_of(cfs_rq)->clock - se->wait_start));
         schedstat_set(se->wait_start, 0);
 }
 
@@ -552,9 +495,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
         /*
          * Any task has to be enqueued before it get to execute on
          * a CPU. So account for the time it spent waiting on the
-         * runqueue. (note, here we rely on pick_next_task() having
-         * done a put_prev_task_fair() shortly before this, which
-         * updated rq->fair_clock - used by update_stats_wait_end())
+         * runqueue.
          */
         update_stats_wait_end(cfs_rq, se);
         update_stats_curr_start(cfs_rq, se);
@@ -989,13 +930,6 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
         update_curr(cfs_rq);
         place_entity(cfs_rq, se, 1);
 
-        /*
-         * The statistical average of wait_runtime is about
-         * -granularity/2, so initialize the task with that:
-         */
-        if (sched_feat(START_DEBIT))
-                se->wait_runtime = -(__sched_period(cfs_rq->nr_running+1) / 2);
-
         if (sysctl_sched_child_runs_first &&
                         curr->vruntime < se->vruntime) {