From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file

---
 kernel/kernel/sched/fair.c |  310 ++++++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 264 insertions(+), 46 deletions(-)

diff --git a/kernel/kernel/sched/fair.c b/kernel/kernel/sched/fair.c
index 97f52cf..8c74c2f 100644
--- a/kernel/kernel/sched/fair.c
+++ b/kernel/kernel/sched/fair.c
@@ -3938,14 +3938,16 @@
 }
 
 #ifdef CONFIG_UCLAMP_TASK
-static inline unsigned long uclamp_task_util(struct task_struct *p)
+static inline unsigned long uclamp_task_util(struct task_struct *p,
+					     unsigned long uclamp_min,
+					     unsigned long uclamp_max)
 {
-	return clamp(task_util_est(p),
-		     uclamp_eff_value(p, UCLAMP_MIN),
-		     uclamp_eff_value(p, UCLAMP_MAX));
+	return clamp(task_util_est(p), uclamp_min, uclamp_max);
 }
 #else
-static inline unsigned long uclamp_task_util(struct task_struct *p)
+static inline unsigned long uclamp_task_util(struct task_struct *p,
+					     unsigned long uclamp_min,
+					     unsigned long uclamp_max)
 {
 	return task_util_est(p);
 }
@@ -4089,9 +4091,135 @@
 	trace_sched_util_est_se_tp(&p->se);
 }
 
-static inline int task_fits_capacity(struct task_struct *p, long capacity)
+static inline int util_fits_cpu(unsigned long util,
+				unsigned long uclamp_min,
+				unsigned long uclamp_max,
+				int cpu)
 {
-	return fits_capacity(uclamp_task_util(p), capacity);
+	unsigned long capacity_orig, capacity_orig_thermal;
+	unsigned long capacity = capacity_of(cpu);
+	bool fits, uclamp_max_fits;
+
+	/*
+	 * Check if the real util fits without any uclamp boost/cap applied.
+	 */
+	fits = fits_capacity(util, capacity);
+
+	if (!uclamp_is_used())
+		return fits;
+
+	/*
+	 * We must use capacity_orig_of() for comparing against uclamp_min and
+	 * uclamp_max. We only care about capacity pressure (by using
+	 * capacity_of()) for comparing against the real util.
+	 *
+	 * If a task is boosted to 1024 for example, we don't want a tiny
+	 * pressure to skew the check whether it fits a CPU or not.
+	 *
+	 * Similarly if a task is capped to capacity_orig_of(little_cpu), it
+	 * should fit a little cpu even if there's some pressure.
+	 *
+	 * Only exception is for thermal pressure since it has a direct impact
+	 * on available OPP of the system.
+	 *
+	 * We honour it for uclamp_min only as a drop in performance level
+	 * could result in not getting the requested minimum performance level.
+	 *
+	 * For uclamp_max, we can tolerate a drop in performance level as the
+	 * goal is to cap the task. So it's okay if it's getting less.
+	 *
+	 * In case of capacity inversion, which is not handled yet, we should
+	 * honour the inverted capacity for both uclamp_min and uclamp_max all
+	 * the time.
+	 */
+	capacity_orig = capacity_orig_of(cpu);
+	capacity_orig_thermal = capacity_orig - arch_scale_thermal_pressure(cpu);
+
+	/*
+	 * We want to force a task to fit a cpu as implied by uclamp_max.
+	 * But we do have some corner cases to cater for..
+	 *
+	 *
+	 *                                 C=z
+	 *   |                             ___
+	 *   |                  C=y       |   |
+	 *   |_ _ _ _ _ _ _ _ _ ___ _ _ _ | _ | _ _ _ _ _  uclamp_max
+	 *   |      C=x        |   |      |   |
+	 *   |      ___        |   |      |   |
+	 *   |     |   |       |   |      |   |    (util somewhere in this region)
+	 *   |     |   |       |   |      |   |
+	 *   |     |   |       |   |      |   |
+	 *   +----------------------------------------
+	 *         cpu0        cpu1       cpu2
+	 *
+	 *   In the above example if a task is capped to a specific performance
+	 *   point, y, then when:
+	 *
+	 *   * util = 80% of x then it does not fit on cpu0 and should migrate
+	 *     to cpu1
+	 *   * util = 80% of y then it is forced to fit on cpu1 to honour
+	 *     uclamp_max request.
+	 *
+	 *   which is what we're enforcing here. A task always fits if
+	 *   uclamp_max <= capacity_orig. But when uclamp_max > capacity_orig,
+	 *   the normal upmigration rules should withhold still.
+	 *
+	 *   Only exception is when we are on max capacity, then we need to be
+	 *   careful not to block overutilized state. This is so because:
+	 *
+	 *     1. There's no concept of capping at max_capacity! We can't go
+	 *        beyond this performance level anyway.
+	 *     2. The system is being saturated when we're operating near
+	 *        max capacity, it doesn't make sense to block overutilized.
+	 */
+	uclamp_max_fits = (capacity_orig == SCHED_CAPACITY_SCALE) && (uclamp_max == SCHED_CAPACITY_SCALE);
+	uclamp_max_fits = !uclamp_max_fits && (uclamp_max <= capacity_orig);
+	fits = fits || uclamp_max_fits;
+
+	/*
+	 *
+	 *                                 C=z
+	 *   |                             ___       (region a, capped, util >= uclamp_max)
+	 *   |                  C=y       |   |
+	 *   |_ _ _ _ _ _ _ _ _ ___ _ _ _ | _ | _ _ _ _ _ uclamp_max
+	 *   |      C=x        |   |      |   |
+	 *   |      ___        |   |      |   |      (region b, uclamp_min <= util <= uclamp_max)
+	 *   |_ _ _|_ _|_ _ _ _| _ | _ _ _| _ | _ _ _ _ _ uclamp_min
+	 *   |     |   |       |   |      |   |
+	 *   |     |   |       |   |      |   |      (region c, boosted, util < uclamp_min)
+	 *   +----------------------------------------
+	 *         cpu0        cpu1       cpu2
+	 *
+	 * a) If util > uclamp_max, then we're capped, we don't care about
+	 *    actual fitness value here. We only care if uclamp_max fits
+	 *    capacity without taking margin/pressure into account.
+	 *    See comment above.
+	 *
+	 * b) If uclamp_min <= util <= uclamp_max, then the normal
+	 *    fits_capacity() rules apply. Except we need to ensure that we
+	 *    enforce we remain within uclamp_max, see comment above.
+	 *
+	 * c) If util < uclamp_min, then we are boosted. Same as (b) but we
+	 *    need to take into account the boosted value fits the CPU without
+	 *    taking margin/pressure into account.
+	 *
+	 * Cases (a) and (b) are handled in the 'fits' variable already. We
+	 * just need to consider an extra check for case (c) after ensuring we
+	 * handle the case uclamp_min > uclamp_max.
+	 */
+	uclamp_min = min(uclamp_min, uclamp_max);
+	if (util < uclamp_min && capacity_orig != SCHED_CAPACITY_SCALE)
+		fits = fits && (uclamp_min <= capacity_orig_thermal);
+
+	return fits;
+}
+
+static inline int task_fits_cpu(struct task_struct *p, int cpu)
+{
+	unsigned long uclamp_min = uclamp_eff_value(p, UCLAMP_MIN);
+	unsigned long uclamp_max = uclamp_eff_value(p, UCLAMP_MAX);
+	unsigned long util = task_util_est(p);
+	return util_fits_cpu(util, uclamp_min, uclamp_max, cpu);
 }
 
 static inline void update_misfit_status(struct task_struct *p, struct rq *rq)
@@ -4107,7 +4235,7 @@
 		return;
 	}
 
-	if (task_fits_capacity(p, capacity_of(cpu_of(rq)))) {
+	if (task_fits_cpu(p, cpu_of(rq))) {
 		rq->misfit_task_load = 0;
 		return;
 	}
@@ -4168,6 +4296,29 @@
 #endif
 }
 
+static inline bool entity_is_long_sleeper(struct sched_entity *se)
+{
+	struct cfs_rq *cfs_rq;
+	u64 sleep_time;
+
+	if (se->exec_start == 0)
+		return false;
+
+	cfs_rq = cfs_rq_of(se);
+
+	sleep_time = rq_clock_task(rq_of(cfs_rq));
+
+	/* Happen while migrating because of clock task divergence */
+	if (sleep_time <= se->exec_start)
+		return false;
+
+	sleep_time -= se->exec_start;
+	if (sleep_time > ((1ULL << 63) / scale_load_down(NICE_0_LOAD)))
+		return true;
+
+	return false;
+}
+
 static void
 place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 {
@@ -4196,8 +4347,29 @@
 		vruntime -= thresh;
 	}
 
-	/* ensure we never gain time by being placed backwards. */
-	se->vruntime = max_vruntime(se->vruntime, vruntime);
+	/*
+	 * Pull vruntime of the entity being placed to the base level of
+	 * cfs_rq, to prevent boosting it if placed backwards.
+	 * However, min_vruntime can advance much faster than real time, with
+	 * the extreme being when an entity with the minimal weight always runs
+	 * on the cfs_rq. If the waking entity slept for a long time, its
+	 * vruntime difference from min_vruntime may overflow s64 and their
+	 * comparison may get inversed, so ignore the entity's original
+	 * vruntime in that case.
+	 * The maximal vruntime speedup is given by the ratio of normal to
+	 * minimal weight: scale_load_down(NICE_0_LOAD) / MIN_SHARES.
+	 * When placing a migrated waking entity, its exec_start has been set
+	 * from a different rq. In order to take into account a possible
+	 * divergence between new and prev rq's clocks task because of irq and
+	 * stolen time, we take an additional margin.
+	 * So, cutting off on the sleep time of
+	 *     2^63 / scale_load_down(NICE_0_LOAD) ~ 104 days
+	 * should be safe.
+	 */
+	if (entity_is_long_sleeper(se))
+		se->vruntime = vruntime;
+	else
+		se->vruntime = max_vruntime(se->vruntime, vruntime);
 	trace_android_rvh_place_entity(cfs_rq, se, initial, vruntime);
 }
 
@@ -4294,6 +4466,9 @@
 
 	if (flags & ENQUEUE_WAKEUP)
 		place_entity(cfs_rq, se, 0);
+	/* Entity has migrated, no longer consider this task hot */
+	if (flags & ENQUEUE_MIGRATED)
+		se->exec_start = 0;
 
 	check_schedstat_required();
 	update_stats_enqueue(cfs_rq, se, flags);
@@ -4431,7 +4606,7 @@
 	if (skip_preempt)
 		return;
 	if (delta_exec > ideal_runtime) {
-		resched_curr_lazy(rq_of(cfs_rq));
+		resched_curr(rq_of(cfs_rq));
 		/*
 		 * The current task ran long enough, ensure it doesn't get
 		 * re-elected due to buddy favours.
@@ -4455,7 +4630,7 @@
 		return;
 
 	if (delta > ideal_runtime)
-		resched_curr_lazy(rq_of(cfs_rq));
+		resched_curr(rq_of(cfs_rq));
 }
 
 void set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -4604,7 +4779,7 @@
 	 * validating it and just reschedule.
 	 */
 	if (queued) {
-		resched_curr_lazy(rq_of(cfs_rq));
+		resched_curr(rq_of(cfs_rq));
 		return;
 	}
 	/*
@@ -4741,7 +4916,7 @@
 	 * hierarchy can be throttled
 	 */
 	if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
-		resched_curr_lazy(rq_of(cfs_rq));
+		resched_curr(rq_of(cfs_rq));
 }
 
 static __always_inline
@@ -5476,7 +5651,7 @@
 
 		if (delta < 0) {
 			if (rq->curr == p)
-				resched_curr_lazy(rq);
+				resched_curr(rq);
 			return;
 		}
 		hrtick_start(rq, delta);
@@ -5514,13 +5689,15 @@
 
 static inline bool cpu_overutilized(int cpu)
 {
+	unsigned long rq_util_min = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MIN);
+	unsigned long rq_util_max = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MAX);
 	int overutilized = -1;
 
 	trace_android_rvh_cpu_overutilized(cpu, &overutilized);
 	if (overutilized != -1)
 		return overutilized;
 
-	return !fits_capacity(cpu_util(cpu), capacity_of(cpu));
+	return !util_fits_cpu(cpu_util(cpu), rq_util_min, rq_util_max, cpu);
 }
 
 static inline void update_overutilized_status(struct rq *rq)
@@ -6262,21 +6439,23 @@
 static int
 select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target)
 {
-	unsigned long task_util, best_cap = 0;
+	unsigned long task_util, util_min, util_max, best_cap = 0;
 	int cpu, best_cpu = -1;
 	struct cpumask *cpus;
 
 	cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
 	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
 
-	task_util = uclamp_task_util(p);
+	task_util = task_util_est(p);
+	util_min = uclamp_eff_value(p, UCLAMP_MIN);
+	util_max = uclamp_eff_value(p, UCLAMP_MAX);
 
 	for_each_cpu_wrap(cpu, cpus, target) {
 		unsigned long cpu_cap = capacity_of(cpu);
 
 		if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu))
 			continue;
-		if (fits_capacity(task_util, cpu_cap))
+		if (util_fits_cpu(task_util, util_min, util_max, cpu))
 			return cpu;
 
 		if (cpu_cap > best_cap) {
@@ -6288,10 +6467,13 @@
 	return best_cpu;
 }
 
-static inline bool asym_fits_capacity(int task_util, int cpu)
+static inline bool asym_fits_cpu(unsigned long util,
+				 unsigned long util_min,
+				 unsigned long util_max,
+				 int cpu)
 {
 	if (static_branch_unlikely(&sched_asym_cpucapacity))
-		return fits_capacity(task_util, capacity_of(cpu));
+		return util_fits_cpu(util, util_min, util_max, cpu);
 
 	return true;
 }
@@ -6302,7 +6484,7 @@
 static int select_idle_sibling(struct task_struct *p, int prev, int target)
 {
 	struct sched_domain *sd;
-	unsigned long task_util;
+	unsigned long task_util, util_min, util_max;
 	int i, recent_used_cpu;
 
 	/*
@@ -6311,11 +6493,13 @@
 	 */
 	if (static_branch_unlikely(&sched_asym_cpucapacity)) {
 		sync_entity_load_avg(&p->se);
-		task_util = uclamp_task_util(p);
+		task_util = task_util_est(p);
+		util_min = uclamp_eff_value(p, UCLAMP_MIN);
+		util_max = uclamp_eff_value(p, UCLAMP_MAX);
 	}
 
 	if ((available_idle_cpu(target) || sched_idle_cpu(target)) &&
-	    asym_fits_capacity(task_util, target))
+	    asym_fits_cpu(task_util, util_min, util_max, target))
 		return target;
 
 	/*
@@ -6323,7 +6507,7 @@
 	 */
 	if (prev != target && cpus_share_cache(prev, target) &&
 	    (available_idle_cpu(prev) || sched_idle_cpu(prev)) &&
-	    asym_fits_capacity(task_util, prev))
+	    asym_fits_cpu(task_util, util_min, util_max, prev))
 		return prev;
 
 	/*
@@ -6338,7 +6522,7 @@
 	    in_task() &&
 	    prev == smp_processor_id() &&
 	    this_rq()->nr_running <= 1 &&
-	    asym_fits_capacity(task_util, prev)) {
+	    asym_fits_cpu(task_util, util_min, util_max, prev)) {
 		return prev;
 	}
 
@@ -6349,7 +6533,7 @@
 	    cpus_share_cache(recent_used_cpu, target) &&
 	    (available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu)) &&
 	    cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) &&
-	    asym_fits_capacity(task_util, recent_used_cpu)) {
+	    asym_fits_cpu(task_util, util_min, util_max, recent_used_cpu)) {
 		/*
 		 * Replace recent_used_cpu with prev as it is a potential
 		 * candidate for the next wake:
@@ -6682,6 +6866,8 @@
 {
 	unsigned long prev_delta = ULONG_MAX, best_delta = ULONG_MAX;
 	unsigned long best_delta2 = ULONG_MAX;
+	unsigned long p_util_min = uclamp_is_used() ? uclamp_eff_value(p, UCLAMP_MIN) : 0;
+	unsigned long p_util_max = uclamp_is_used() ? uclamp_eff_value(p, UCLAMP_MAX) : 1024;
 	struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
 	int max_spare_cap_cpu_ls = prev_cpu, best_idle_cpu = -1;
 	unsigned long max_spare_cap_ls = 0, target_cap;
@@ -6707,7 +6893,7 @@
 	cpu = smp_processor_id();
 	if (sync && cpu_rq(cpu)->nr_running == 1 &&
 	    cpumask_test_cpu(cpu, p->cpus_ptr) &&
-	    task_fits_capacity(p, capacity_of(cpu))) {
+	    task_fits_cpu(p, cpu)) {
 		rcu_read_unlock();
 		return cpu;
 	}
@@ -6722,7 +6908,7 @@
 	if (!sd)
 		goto fail;
 
-	if (!task_util_est(p))
+	if (!uclamp_task_util(p, p_util_min, p_util_max))
 		goto unlock;
 
 	latency_sensitive = uclamp_latency_sensitive(p);
@@ -6731,6 +6917,8 @@
 
 	for (; pd; pd = pd->next) {
 		unsigned long cur_delta, spare_cap, max_spare_cap = 0;
+		unsigned long rq_util_min, rq_util_max;
+		unsigned long util_min, util_max;
 		unsigned long base_energy_pd;
 		int max_spare_cap_cpu = -1;
 
@@ -6754,8 +6942,26 @@
 			 * much capacity we can get out of the CPU; this is
 			 * aligned with schedutil_cpu_util().
 			 */
-			util = uclamp_rq_util_with(cpu_rq(cpu), util, p);
-			if (!fits_capacity(util, cpu_cap))
+			if (uclamp_is_used()) {
+				if (uclamp_rq_is_idle(cpu_rq(cpu))) {
+					util_min = p_util_min;
+					util_max = p_util_max;
+				} else {
+					/*
+					 * Open code uclamp_rq_util_with() except for
+					 * the clamp() part. Ie: apply max aggregation
+					 * only. util_fits_cpu() logic requires to
+					 * operate on non clamped util but must use the
+					 * max-aggregated uclamp_{min, max}.
+					 */
+					rq_util_min = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MIN);
+					rq_util_max = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MAX);
+
+					util_min = max(rq_util_min, p_util_min);
+					util_max = max(rq_util_max, p_util_max);
+				}
+			}
+			if (!util_fits_cpu(util, util_min, util_max, cpu))
 				continue;
 
 			/* Always use prev_cpu as a candidate. */
@@ -7035,9 +7241,6 @@
 	/* Tell new CPU we are migrated */
 	p->se.avg.last_update_time = 0;
 
-	/* We have migrated, no longer consider this task hot */
-	p->se.exec_start = 0;
-
 	update_scan_period(p, new_cpu);
 }
 
@@ -7211,7 +7414,7 @@
 	return;
 
 preempt:
-	resched_curr_lazy(rq);
+	resched_curr(rq);
 	/*
 	 * Only set the backward buddy when the current task is still
 	 * on the rq. This can happen when a wakeup gets interleaved
@@ -7983,7 +8186,7 @@
 
 		case migrate_misfit:
 			/* This is not a misfit task */
-			if (task_fits_capacity(p, capacity_of(env->src_cpu)))
+			if (task_fits_cpu(p, env->src_cpu))
 				goto next;
 
 			env->imbalance = 0;
@@ -8926,6 +9129,10 @@
 
 	memset(sgs, 0, sizeof(*sgs));
 
+	/* Assume that task can't fit any CPU of the group */
+	if (sd->flags & SD_ASYM_CPUCAPACITY)
+		sgs->group_misfit_task_load = 1;
+
 	for_each_cpu(i, sched_group_span(group)) {
 		struct rq *rq = cpu_rq(i);
 		unsigned int local;
@@ -8945,12 +9152,12 @@
 		if (!nr_running && idle_cpu_without(i, p))
 			sgs->idle_cpus++;
 
-	}
+		/* Check if task fits in the CPU */
+		if (sd->flags & SD_ASYM_CPUCAPACITY &&
+		    sgs->group_misfit_task_load &&
+		    task_fits_cpu(p, i))
+			sgs->group_misfit_task_load = 0;
 
-	/* Check if task fits in the group */
-	if (sd->flags & SD_ASYM_CPUCAPACITY &&
-	    !task_fits_capacity(p, group->sgc->max_capacity)) {
-		sgs->group_misfit_task_load = 1;
 	}
 
 	sgs->group_capacity = group->sgc->capacity;
@@ -9395,8 +9602,6 @@
 		local->avg_load = (local->group_load * SCHED_CAPACITY_SCALE) /
 				  local->group_capacity;
 
-		sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
-				sds->total_capacity;
 		/*
 		 * If the local group is more loaded than the selected
 		 * busiest group don't try to pull any tasks.
@@ -9405,6 +9610,19 @@
 			env->imbalance = 0;
 			return;
 		}
+
+		sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
+				sds->total_capacity;
+
+		/*
+		 * If the local group is more loaded than the average system
+		 * load, don't try to pull any tasks.
+		 */
+		if (local->avg_load >= sds->avg_load) {
+			env->imbalance = 0;
+			return;
+		}
+
 	}
 
 	/*
@@ -9837,7 +10055,7 @@
 		.sd		= sd,
 		.dst_cpu	= this_cpu,
 		.dst_rq		= this_rq,
-		.dst_grpmask    = sched_group_span(sd->groups),
+		.dst_grpmask    = group_balance_mask(sd->groups),
 		.idle		= idle,
 		.loop_break	= sched_nr_migrate_break,
 		.cpus		= cpus,
@@ -11060,7 +11278,7 @@
 		 * 'current' within the tree based on its new key value.
 		 */
 		swap(curr->vruntime, se->vruntime);
-		resched_curr_lazy(rq);
+		resched_curr(rq);
 	}
 
 	se->vruntime -= cfs_rq->min_vruntime;
@@ -11087,7 +11305,7 @@
 	 */
 	if (rq->curr == p) {
 		if (p->prio > oldprio)
-			resched_curr_lazy(rq);
+			resched_curr(rq);
 	} else
 		check_preempt_curr(rq, p, 0);
 }

--
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