sched: Improve the scheduler

This change is for general scheduler improvement.

Change-Id: I18364c6061ed7525755aaf187bf15a8cb9b54a8a
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>

include/linux/sched.h

@@ -801,6 +801,7 @@ struct task_struct {
 	struct list_head grp_list;
 	u64 cpu_cycles;
 	bool misfit;
+	u8 unfilter;
 #endif
 
 #ifdef CONFIG_CGROUP_SCHED

include/linux/sched/sysctl.h

@@ -42,6 +42,8 @@ extern unsigned int sysctl_sched_min_task_util_for_boost;
 extern unsigned int sysctl_sched_min_task_util_for_colocation;
 extern unsigned int sysctl_sched_asym_cap_sibling_freq_match_pct;
 extern unsigned int sysctl_sched_coloc_downmigrate_ns;
+extern unsigned int sysctl_sched_task_unfilter_nr_windows;
+
 extern int
 walt_proc_group_thresholds_handler(struct ctl_table *table, int write,
 			 void __user *buffer, size_t *lenp,

include/trace/events/sched.h

@@ -1234,6 +1234,7 @@ TRACE_EVENT(sched_task_util,
 		__field(bool,		is_rtg)
 		__field(bool,		rtg_skip_min)
 		__field(int,		start_cpu)
+		__field(int,		unfilter)
 	),
 
 	TP_fast_assign(
@@ -1252,14 +1253,16 @@ TRACE_EVENT(sched_task_util,
 		__entry->is_rtg                 = is_rtg;
 		__entry->rtg_skip_min		= rtg_skip_min;
 		__entry->start_cpu		= start_cpu;
+		__entry->unfilter		= p->unfilter;
 	),
 
-	TP_printk("pid=%d comm=%s util=%lu prev_cpu=%d candidates=%#lx best_energy_cpu=%d sync=%d need_idle=%d fastpath=%d placement_boost=%d latency=%llu stune_boosted=%d is_rtg=%d rtg_skip_min=%d start_cpu=%d",
+	TP_printk("pid=%d comm=%s util=%lu prev_cpu=%d candidates=%#lx best_energy_cpu=%d sync=%d need_idle=%d fastpath=%d placement_boost=%d latency=%llu stune_boosted=%d is_rtg=%d rtg_skip_min=%d start_cpu=%d unfilter=%d",
 		__entry->pid, __entry->comm, __entry->util, __entry->prev_cpu,
 		__entry->candidates, __entry->best_energy_cpu, __entry->sync,
 		__entry->need_idle, __entry->fastpath, __entry->placement_boost,
 		__entry->latency, __entry->stune_boosted,
-		__entry->is_rtg, __entry->rtg_skip_min, __entry->start_cpu)
+		__entry->is_rtg, __entry->rtg_skip_min, __entry->start_cpu,
+		__entry->unfilter)
 )
 
 /*

kernel/sched/fair.c

@@ -6733,8 +6733,8 @@ static int get_start_cpu(struct task_struct *p)
 	int start_cpu = rd->min_cap_orig_cpu;
 	bool boosted = schedtune_task_boost(p) > 0 ||
 			task_boost_policy(p) == SCHED_BOOST_ON_BIG;
-	bool task_skip_min = get_rtg_status(p) &&
-		(task_util(p) > sched_task_filter_util);
+	bool task_skip_min = (sched_boost() != CONSERVATIVE_BOOST)
+				&& get_rtg_status(p) && p->unfilter;
 
 	/*
 	 * note about min/mid/max_cap_orig_cpu - either all of them will be -ve

kernel/sched/walt.c

@@ -1727,6 +1727,8 @@ account_busy_for_task_demand(struct rq *rq, struct task_struct *p, int event)
 	return 1;
 }
 
+unsigned int sysctl_sched_task_unfilter_nr_windows = 10;
+
 /*
  * Called when new window is starting for a task, to record cpu usage over
  * recently concluded window(s). Normally 'samples' should be 1. It can be > 1
@@ -1807,6 +1809,12 @@ static void update_history(struct rq *rq, struct task_struct *p,
 	p->ravg.pred_demand = pred_demand;
 	p->ravg.pred_demand_scaled = pred_demand_scaled;
 
+	if (demand_scaled > sched_task_filter_util)
+		p->unfilter = sysctl_sched_task_unfilter_nr_windows;
+	else
+		if (p->unfilter)
+			p->unfilter = p->unfilter - 1;
+
 done:
 	trace_sched_update_history(rq, p, runtime, samples, event);
 }
@@ -2087,6 +2095,7 @@ void init_new_task_load(struct task_struct *p)
 	for (i = 0; i < RAVG_HIST_SIZE_MAX; ++i)
 		p->ravg.sum_history[i] = init_load_windows;
 	p->misfit = false;
+	p->unfilter = sysctl_sched_task_unfilter_nr_windows;
 }
 
 /*

kernel/sysctl.c

@@ -420,7 +420,15 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_douintvec_minmax,
 	},
-
+	{
+		.procname	= "sched_task_unfilter_nr_windows",
+		.data		= &sysctl_sched_task_unfilter_nr_windows,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler   = proc_dointvec_minmax,
+		.extra1         = &zero,
+		.extra2		= &two_hundred_fifty_five,
+	},
 #endif
 #ifdef CONFIG_SMP
 	{