[COMMON] sched/rt: repair the core selecting algorithm

including,
* reworking a rq-selecting algorithm rq for fluid rt
* fix the wrong tracing info

Change-Id: If3d9695252d019fd277a80d9d4314259fa6ced16
Signed-off-by: Johnlay Park <jonglae.park@samsung.com>

diff --git a/kernel/sched/ems/core.c b/kernel/sched/ems/core.c
index 341eb2e0c4add6e6c455953345158f747c08280b..db729fbc141ef514caa54c78d860aa6de09f1829 100644 (file)
--- a/kernel/sched/ems/core.c
+++ b/kernel/sched/ems/core.c
@@ -15,7 +15,10 @@
 
 int task_util(struct task_struct *p)
 {
-       return p->se.avg.util_avg;
+       if (rt_task(p))
+               return p->rt.avg.util_avg;
+       else
+               return p->se.avg.util_avg;
 }
 
 int cpu_util_wake(int cpu, struct task_struct *p)

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a223e4f7249381dd5e6ed62450ccc228a705c680..883a5374cfd1331674df0aae8aeef69dced7612a 100644 (file)
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1618,7 +1618,7 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags,
 out:
 #ifdef CONFIG_SCHED_USE_FLUID_RT
        if (cpu >= 6)
-               trace_sched_fluid_stat(p, &p->se.avg, cpu, "BIG_ASSIGED");
+               trace_sched_fluid_stat(p, &p->rt.avg, cpu, "BIG_ASSIGED");
 #endif
        return cpu;
 }
@@ -2241,7 +2241,7 @@ static inline int affordable_cpu(int cpu, unsigned long task_load)
 
 extern unsigned long cpu_util_wake(int cpu, struct task_struct *p);
 extern unsigned long task_util(struct task_struct *p);
-
+static inline int cpu_selected(int cpu)        { return (nr_cpu_ids > cpu && cpu >= 0); }
 /*
  * Must find the victim or recessive (not in lowest_mask)
  *
@@ -2249,8 +2249,7 @@ extern unsigned long task_util(struct task_struct *p);
 /* Future-safe accessor for struct task_struct's cpus_allowed. */
 #define rttsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
 
-static int find_victim_rt_rq(struct task_struct *task, struct sched_group *sg, int *best_cpu) {
-       struct cpumask *sg_cpus = sched_group_cpus_rt(sg);
+static int find_victim_rt_rq(struct task_struct *task, const struct cpumask *sg_cpus, int *best_cpu) {
        int i;
        unsigned long victim_rtweight, target_rtweight, min_rtweight;
        unsigned int victim_cpu_cap, min_cpu_cap = arch_scale_cpu_capacity(NULL, task_cpu(task));
@@ -2304,9 +2303,9 @@ static int find_victim_rt_rq(struct task_struct *task, struct sched_group *sg, i
        }
 
        if (victim_rt)
-               trace_sched_fluid_stat(task, &task->se.avg, *best_cpu, "VICTIM-FAIR");
+               trace_sched_fluid_stat(task, &task->rt.avg, *best_cpu, "VICTIM-FAIR");
        else
-               trace_sched_fluid_stat(task, &task->se.avg, *best_cpu, "VICTIM-RT");
+               trace_sched_fluid_stat(task, &task->rt.avg, *best_cpu, "VICTIM-RT");
 
        return *best_cpu;
 
@@ -2314,23 +2313,22 @@ static int find_victim_rt_rq(struct task_struct *task, struct sched_group *sg, i
 
 static int find_lowest_rq_fluid(struct task_struct *task, int wake_flags)
 {
-       int cpu, best_cpu = -1;
+       int cpu, icpu, best_cpu = -1;
        int prefer_cpu = smp_processor_id();    /* Cache-hot with itself or waker (default). */
-       int boosted = 0;
        struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask);
-       struct sched_domain *sd;
-       struct sched_group *sg;
+
        u64 cpu_load = ULLONG_MAX, min_load = ULLONG_MAX, min_rt_load = ULLONG_MAX;
+       u64 min_icl = ULLONG_MAX;
        int min_cpu = -1, min_rt_cpu = -1;
 
        /* Make sure the mask is initialized first */
        if (unlikely(!lowest_mask)) {
-               trace_sched_fluid_stat(task, &task->se.avg, best_cpu, "NA LOWESTMSK");
+               trace_sched_fluid_stat(task, &task->rt.avg, best_cpu, "NA LOWESTMSK");
                goto out;
        }
 
        if (task->nr_cpus_allowed == 1) {
-               trace_sched_fluid_stat(task, &task->se.avg, best_cpu, "NA ALLOWED");
+               trace_sched_fluid_stat(task, &task->rt.avg, best_cpu, "NA ALLOWED");
                goto out; /* No other targets possible */
        }
 
@@ -2349,108 +2347,117 @@ static int find_lowest_rq_fluid(struct task_struct *task, int wake_flags)
 
        /*
         * 1. Cache hot : packing the callee and caller,
-        *      when there is nothing to run except callee
+        *      when there is nothing to run except callee, or
+        *      wake_flags are set.
         */
+       /* FUTURE WORK: Hierarchical cache hot */
        if ((wake_flags || affordable_cpu(prefer_cpu, task_util(task))) &&
                cpumask_test_cpu(prefer_cpu, cpu_online_mask)) {
                task->rt.sync_flag = 1;
                best_cpu = prefer_cpu;
-               trace_sched_fluid_stat(task, &task->se.avg, best_cpu, "CACHE-HOT");
+               trace_sched_fluid_stat(task, &task->rt.avg, best_cpu, "CACHE-HOT");
                goto out;
        }
 
-       prefer_cpu = task_cpu(task);
-
        /*
         * 2. idle CPU selection
         */
-       boosted = (task->rt.avg.util_avg > sched_rt_boost_threshold) ? (1) : (0);
+       prefer_cpu = task_cpu(task);
+       prefer_cpu = (task->rt.avg.util_avg > sched_rt_boost_threshold) ?
+               cpumask_first(cpu_coregroup_mask(prefer_cpu)) :
+               cpumask_first(cpu_online_mask);
 
        /* TODO: Need to refer the scheduling status of eHMP */
-       for_each_cpu_and(cpu, rttsk_cpus_allowed(task), cpu_online_mask){
-               if (boosted && cpu < cpumask_first(cpu_coregroup_mask(prefer_cpu)))
+       for_each_online_cpu(cpu){
+               const struct cpumask* traversingDom = cpu_coregroup_mask(cpu);
+               if (cpu != cpumask_first(traversingDom))
+                       continue;
+
+               if (cpumask_first(traversingDom) < prefer_cpu)
                        continue;
 
-               if (idle_cpu(cpu)) {
-                       best_cpu = cpu;
-                       trace_sched_fluid_stat(task, &task->se.avg, best_cpu, "IDLE-FIRST");
+               for_each_cpu_and(icpu, rttsk_cpus_allowed(task), traversingDom) {
+                       if (idle_cpu(icpu)) {
+                               cpu_load = cpu_util_wake(icpu, task) + task_util(task);
+                               if ((min_icl > cpu_load) ||
+                                       (min_icl == cpu_load && task_cpu(task) == icpu)) {
+                                       min_icl = cpu_load;
+                                       best_cpu = icpu;
+                               }
+                       }
+               }
+
+               if (cpu_selected(best_cpu)) {
+                       trace_sched_fluid_stat(task, &task->rt.avg, best_cpu, "IDLE-FIRST");
                        goto out;
                }
        }
 
-       rcu_read_lock();
-
-       sd = boosted ?
-               rcu_dereference(per_cpu(sd_ea, 0)) :
-               rcu_dereference(per_cpu(sd_ea, prefer_cpu));
-
-       if (!sd)
-               goto unlock;
-
-       sg = sd->groups;
-
        /*
         * 3. recessive task first
         */
-       do {
-               for_each_cpu_and(cpu, sched_group_span(sg), lowest_mask) {
+       prefer_cpu = task_cpu(task);
+
+       for_each_online_cpu(cpu) {
+               if (cpu != cpumask_first(cpu_coregroup_mask(cpu)))
+                       continue;
+
+               for_each_cpu_and(icpu, rttsk_cpus_allowed(task), cpu_coregroup_mask(cpu)) {
+                       if (!cpumask_test_cpu(icpu, lowest_mask))
+                               continue;
 
-                       cpu_load = cpu_util_wake(cpu, task) + task_util(task);
+                       cpu_load = cpu_util_wake(icpu, task) + task_util(task);
 
-                       if (rt_task(cpu_rq(cpu)->curr)) {
+                       if (rt_task(cpu_rq(icpu)->curr)) {
                                if (cpu_load < min_rt_load ||
-                                       (cpu_load == min_rt_load && cpu == prefer_cpu)) {
+                                       (cpu_load == min_rt_load && icpu == prefer_cpu)) {
                                        min_rt_load = cpu_load;
-                                       min_rt_cpu = cpu;
+                                       min_rt_cpu = icpu;
                                }
-
                                continue;
                        }
                        if (cpu_load < min_load ||
-                               (cpu_load == min_load && cpu == prefer_cpu)) {
+                               (cpu_load == min_load && icpu == prefer_cpu)) {
                                min_load = cpu_load;
-                               min_cpu = cpu;
+                               min_cpu = icpu;
                        }
 
                }
-
                /* Fair recessive task : best min-load of non-rt cpu is exist? */
-               if (min_cpu >= 0 &&
+               if (cpu_selected(min_cpu) &&
                        ((capacity_of(min_cpu) >= min_load) || (min_cpu == prefer_cpu))) {
                        best_cpu = min_cpu;
-                       trace_sched_fluid_stat(task, &task->se.avg, best_cpu, "FAIR-RECESS");
-                       goto unlock;
+                       trace_sched_fluid_stat(task, &task->rt.avg, best_cpu, "FAIR-RECESS");
+                       goto out;
                }
 
                /* RT recessive task : best min-load of rt cpu is exist? */
-               if (min_rt_cpu >= 0 &&
-                       ((capacity_of(min_rt_cpu) >= min_rt_load) || (min_rt_cpu == prefer_cpu))) {
+               if (cpu_selected(min_rt_cpu) &&
+                       ((capacity_of(min_rt_cpu) > min_rt_load) || (min_rt_cpu == prefer_cpu))) {
                        best_cpu = min_rt_cpu;
-                       trace_sched_fluid_stat(task, &task->se.avg, best_cpu, "RT-RECESS");
-                       goto unlock;
+                       trace_sched_fluid_stat(task, &task->rt.avg, best_cpu, "RT-RECESS");
+                       goto out;
                }
-
-       } while (sg = sg->next, sg != sd->groups);
-       /* need to check the method for traversing the sg */
-
-       sg = sd->groups;
+       }
 
        /*
         * 4. victim task first
         */
-       do {
-               if (find_victim_rt_rq(task, sg, &best_cpu) != -1)
+       for_each_online_cpu(cpu) {
+               if (cpu != cpumask_first(cpu_coregroup_mask(cpu)))
+                       continue;
+
+               if (find_victim_rt_rq(task, cpu_coregroup_mask(cpu), &best_cpu) != -1)
                        break;
-       } while (sg = sg->next, sg != sd->groups);
+       }
 
-       if (best_cpu < 0)
+       if (!cpu_selected(best_cpu))
                best_cpu = prefer_cpu;
-unlock:
-       rcu_read_unlock();
+
 out:
 
        if (!cpumask_test_cpu(best_cpu, cpu_online_mask)) {
-               trace_sched_fluid_stat(task, &task->se.avg, cpu, "NOTHING_VALID");
+               trace_sched_fluid_stat(task, &task->rt.avg, cpu, "NOTHING_VALID");
                best_cpu = -1;
        }
 
@@ -2563,7 +2570,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
                         * If the sync flag is set,
                         * let the task go even though its priority is same with current.
                         */
-                       trace_sched_fluid_stat(task, &task->se.avg, cpu, "SYNC AGAIN");
+                       trace_sched_fluid_stat(task, &task->rt.avg, cpu, "SYNC AGAIN");
                } else
  #else
                if (lowest_rq->rt.highest_prio.curr <= task->prio)