diff -drupN a/kernel/sched/walt.c b/kernel/sched/walt.c
--- a/kernel/sched/walt.c	1970-01-01 03:00:00.000000000 +0300
+++ b/kernel/sched/walt.c	2022-06-12 05:28:14.000000000 +0300
@@ -0,0 +1,903 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ *
+ * Window Assisted Load Tracking (WALT) implementation credits:
+ * Srivatsa Vaddagiri, Steve Muckle, Syed Rameez Mustafa, Joonwoo Park,
+ * Pavan Kumar Kondeti, Olav Haugan
+ *
+ * 2016-03-06: Integration with EAS/refactoring by Vikram Mulukutla
+ *             and Todd Kjos
+ */
+
+#include <linux/acpi.h>
+#include <linux/syscore_ops.h>
+#include <trace/events/sched.h>
+#include "sched.h"
+#include "walt.h"
+
+#define WINDOW_STATS_RECENT		0
+#define WINDOW_STATS_MAX		1
+#define WINDOW_STATS_MAX_RECENT_AVG	2
+#define WINDOW_STATS_AVG		3
+#define WINDOW_STATS_INVALID_POLICY	4
+
+#define EXITING_TASK_MARKER	0xdeaddead
+
+static __read_mostly unsigned int walt_ravg_hist_size = 5;
+static __read_mostly unsigned int walt_window_stats_policy =
+	WINDOW_STATS_MAX_RECENT_AVG;
+static __read_mostly unsigned int walt_account_wait_time = 1;
+static __read_mostly unsigned int walt_freq_account_wait_time = 0;
+static __read_mostly unsigned int walt_io_is_busy = 0;
+
+unsigned int sysctl_sched_walt_init_task_load_pct = 15;
+
+/* true -> use PELT based load stats, false -> use window-based load stats */
+bool __read_mostly walt_disabled = false;
+
+/*
+ * Window size (in ns). Adjust for the tick size so that the window
+ * rollover occurs just before the tick boundary.
+ */
+__read_mostly unsigned int walt_ravg_window =
+					    (20000000 / TICK_NSEC) * TICK_NSEC;
+#define MIN_SCHED_RAVG_WINDOW ((10000000 / TICK_NSEC) * TICK_NSEC)
+#define MAX_SCHED_RAVG_WINDOW ((1000000000 / TICK_NSEC) * TICK_NSEC)
+
+static unsigned int sync_cpu;
+static ktime_t ktime_last;
+static __read_mostly bool walt_ktime_suspended;
+
+static unsigned int task_load(struct task_struct *p)
+{
+	return p->ravg.demand;
+}
+
+static inline void fixup_cum_window_demand(struct rq *rq, s64 delta)
+{
+	rq->cum_window_demand += delta;
+	if (unlikely((s64)rq->cum_window_demand < 0))
+		rq->cum_window_demand = 0;
+}
+
+void
+walt_inc_cumulative_runnable_avg(struct rq *rq,
+				 struct task_struct *p)
+{
+	rq->cumulative_runnable_avg += p->ravg.demand;
+
+	/*
+	 * Add a task's contribution to the cumulative window demand when
+	 *
+	 * (1) task is enqueued with on_rq = 1 i.e migration,
+	 *     prio/cgroup/class change.
+	 * (2) task is waking for the first time in this window.
+	 */
+	if (p->on_rq || (p->last_sleep_ts < rq->window_start))
+		fixup_cum_window_demand(rq, p->ravg.demand);
+}
+
+void
+walt_dec_cumulative_runnable_avg(struct rq *rq,
+				 struct task_struct *p)
+{
+	rq->cumulative_runnable_avg -= p->ravg.demand;
+	BUG_ON((s64)rq->cumulative_runnable_avg < 0);
+
+	/*
+	 * on_rq will be 1 for sleeping tasks. So check if the task
+	 * is migrating or dequeuing in RUNNING state to change the
+	 * prio/cgroup/class.
+	 */
+	if (task_on_rq_migrating(p) || p->state == TASK_RUNNING)
+		fixup_cum_window_demand(rq, -(s64)p->ravg.demand);
+}
+
+static void
+fixup_cumulative_runnable_avg(struct rq *rq,
+			      struct task_struct *p, u64 new_task_load)
+{
+	s64 task_load_delta = (s64)new_task_load - task_load(p);
+
+	rq->cumulative_runnable_avg += task_load_delta;
+	if ((s64)rq->cumulative_runnable_avg < 0)
+		panic("cra less than zero: tld: %lld, task_load(p) = %u\n",
+			task_load_delta, task_load(p));
+
+	fixup_cum_window_demand(rq, task_load_delta);
+}
+
+u64 walt_ktime_clock(void)
+{
+	if (unlikely(walt_ktime_suspended))
+		return ktime_to_ns(ktime_last);
+	return ktime_get_ns();
+}
+
+static void walt_resume(void)
+{
+	walt_ktime_suspended = false;
+}
+
+static int walt_suspend(void)
+{
+	ktime_last = ktime_get();
+	walt_ktime_suspended = true;
+	return 0;
+}
+
+static struct syscore_ops walt_syscore_ops = {
+	.resume	= walt_resume,
+	.suspend = walt_suspend
+};
+
+static int __init walt_init_ops(void)
+{
+	register_syscore_ops(&walt_syscore_ops);
+	return 0;
+}
+late_initcall(walt_init_ops);
+
+#ifdef CONFIG_CFS_BANDWIDTH
+void walt_inc_cfs_cumulative_runnable_avg(struct cfs_rq *cfs_rq,
+		struct task_struct *p)
+{
+	cfs_rq->cumulative_runnable_avg += p->ravg.demand;
+}
+
+void walt_dec_cfs_cumulative_runnable_avg(struct cfs_rq *cfs_rq,
+		struct task_struct *p)
+{
+	cfs_rq->cumulative_runnable_avg -= p->ravg.demand;
+}
+#endif
+
+static int exiting_task(struct task_struct *p)
+{
+	if (p->flags & PF_EXITING) {
+		if (p->ravg.sum_history[0] != EXITING_TASK_MARKER) {
+			p->ravg.sum_history[0] = EXITING_TASK_MARKER;
+		}
+		return 1;
+	}
+	return 0;
+}
+
+static int __init set_walt_ravg_window(char *str)
+{
+	unsigned int adj_window;
+	bool no_walt = walt_disabled;
+
+	get_option(&str, &walt_ravg_window);
+
+	/* Adjust for CONFIG_HZ */
+	adj_window = (walt_ravg_window / TICK_NSEC) * TICK_NSEC;
+
+	/* Warn if we're a bit too far away from the expected window size */
+	WARN(adj_window < walt_ravg_window - NSEC_PER_MSEC,
+	     "tick-adjusted window size %u, original was %u\n", adj_window,
+	     walt_ravg_window);
+
+	walt_ravg_window = adj_window;
+
+	walt_disabled = walt_disabled ||
+			(walt_ravg_window < MIN_SCHED_RAVG_WINDOW ||
+			 walt_ravg_window > MAX_SCHED_RAVG_WINDOW);
+
+	WARN(!no_walt && walt_disabled,
+	     "invalid window size, disabling WALT\n");
+
+	return 0;
+}
+
+early_param("walt_ravg_window", set_walt_ravg_window);
+
+static void
+update_window_start(struct rq *rq, u64 wallclock)
+{
+	s64 delta;
+	int nr_windows;
+
+	delta = wallclock - rq->window_start;
+	/* If the MPM global timer is cleared, set delta as 0 to avoid kernel BUG happening */
+	if (delta < 0) {
+		delta = 0;
+		WARN_ONCE(1, "WALT wallclock appears to have gone backwards or reset\n");
+	}
+
+	if (delta < walt_ravg_window)
+		return;
+
+	nr_windows = div64_u64(delta, walt_ravg_window);
+	rq->window_start += (u64)nr_windows * (u64)walt_ravg_window;
+
+	rq->cum_window_demand = rq->cumulative_runnable_avg;
+}
+
+/*
+ * Translate absolute delta time accounted on a CPU
+ * to a scale where 1024 is the capacity of the most
+ * capable CPU running at FMAX
+ */
+static u64 scale_exec_time(u64 delta, struct rq *rq)
+{
+	unsigned long capcurr = capacity_curr_of(cpu_of(rq));
+
+	return (delta * capcurr) >> SCHED_CAPACITY_SHIFT;
+}
+
+static int cpu_is_waiting_on_io(struct rq *rq)
+{
+	if (!walt_io_is_busy)
+		return 0;
+
+	return atomic_read(&rq->nr_iowait);
+}
+
+void walt_account_irqtime(int cpu, struct task_struct *curr,
+				 u64 delta, u64 wallclock)
+{
+	struct rq *rq = cpu_rq(cpu);
+	unsigned long flags, nr_windows;
+	u64 cur_jiffies_ts;
+
+	raw_spin_lock_irqsave(&rq->lock, flags);
+
+	/*
+	 * cputime (wallclock) uses sched_clock so use the same here for
+	 * consistency.
+	 */
+	delta += sched_clock() - wallclock;
+	cur_jiffies_ts = get_jiffies_64();
+
+	if (is_idle_task(curr))
+		walt_update_task_ravg(curr, rq, IRQ_UPDATE, walt_ktime_clock(),
+				 delta);
+
+	nr_windows = cur_jiffies_ts - rq->irqload_ts;
+
+	if (nr_windows) {
+		if (nr_windows < 10) {
+			/* Decay CPU's irqload by 3/4 for each window. */
+			rq->avg_irqload *= (3 * nr_windows);
+			rq->avg_irqload = div64_u64(rq->avg_irqload,
+						    4 * nr_windows);
+		} else {
+			rq->avg_irqload = 0;
+		}
+		rq->avg_irqload += rq->cur_irqload;
+		rq->cur_irqload = 0;
+	}
+
+	rq->cur_irqload += delta;
+	rq->irqload_ts = cur_jiffies_ts;
+	raw_spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+
+#define WALT_HIGH_IRQ_TIMEOUT 3
+
+u64 walt_irqload(int cpu) {
+	struct rq *rq = cpu_rq(cpu);
+	s64 delta;
+	delta = get_jiffies_64() - rq->irqload_ts;
+
+        /*
+	 * Current context can be preempted by irq and rq->irqload_ts can be
+	 * updated by irq context so that delta can be negative.
+	 * But this is okay and we can safely return as this means there
+	 * was recent irq occurrence.
+	 */
+
+        if (delta < WALT_HIGH_IRQ_TIMEOUT)
+		return rq->avg_irqload;
+        else
+		return 0;
+}
+
+int walt_cpu_high_irqload(int cpu) {
+	return walt_irqload(cpu) >= sysctl_sched_walt_cpu_high_irqload;
+}
+
+static int account_busy_for_cpu_time(struct rq *rq, struct task_struct *p,
+				     u64 irqtime, int event)
+{
+	if (is_idle_task(p)) {
+		/* TASK_WAKE && TASK_MIGRATE is not possible on idle task! */
+		if (event == PICK_NEXT_TASK)
+			return 0;
+
+		/* PUT_PREV_TASK, TASK_UPDATE && IRQ_UPDATE are left */
+		return irqtime || cpu_is_waiting_on_io(rq);
+	}
+
+	if (event == TASK_WAKE)
+		return 0;
+
+	if (event == PUT_PREV_TASK || event == IRQ_UPDATE ||
+					 event == TASK_UPDATE)
+		return 1;
+
+	/* Only TASK_MIGRATE && PICK_NEXT_TASK left */
+	return walt_freq_account_wait_time;
+}
+
+/*
+ * Account cpu activity in its busy time counters (rq->curr/prev_runnable_sum)
+ */
+static void update_cpu_busy_time(struct task_struct *p, struct rq *rq,
+	     int event, u64 wallclock, u64 irqtime)
+{
+	int new_window, nr_full_windows = 0;
+	int p_is_curr_task = (p == rq->curr);
+	u64 mark_start = p->ravg.mark_start;
+	u64 window_start = rq->window_start;
+	u32 window_size = walt_ravg_window;
+	u64 delta;
+
+	new_window = mark_start < window_start;
+	if (new_window) {
+		nr_full_windows = div64_u64((window_start - mark_start),
+						window_size);
+		if (p->ravg.active_windows < USHRT_MAX)
+			p->ravg.active_windows++;
+	}
+
+	/* Handle per-task window rollover. We don't care about the idle
+	 * task or exiting tasks. */
+	if (new_window && !is_idle_task(p) && !exiting_task(p)) {
+		u32 curr_window = 0;
+
+		if (!nr_full_windows)
+			curr_window = p->ravg.curr_window;
+
+		p->ravg.prev_window = curr_window;
+		p->ravg.curr_window = 0;
+	}
+
+	if (!account_busy_for_cpu_time(rq, p, irqtime, event)) {
+		/* account_busy_for_cpu_time() = 0, so no update to the
+		 * task's current window needs to be made. This could be
+		 * for example
+		 *
+		 *   - a wakeup event on a task within the current
+		 *     window (!new_window below, no action required),
+		 *   - switching to a new task from idle (PICK_NEXT_TASK)
+		 *     in a new window where irqtime is 0 and we aren't
+		 *     waiting on IO */
+
+		if (!new_window)
+			return;
+
+		/* A new window has started. The RQ demand must be rolled
+		 * over if p is the current task. */
+		if (p_is_curr_task) {
+			u64 prev_sum = 0;
+
+			/* p is either idle task or an exiting task */
+			if (!nr_full_windows) {
+				prev_sum = rq->curr_runnable_sum;
+			}
+
+			rq->prev_runnable_sum = prev_sum;
+			rq->curr_runnable_sum = 0;
+		}
+
+		return;
+	}
+
+	if (!new_window) {
+		/* account_busy_for_cpu_time() = 1 so busy time needs
+		 * to be accounted to the current window. No rollover
+		 * since we didn't start a new window. An example of this is
+		 * when a task starts execution and then sleeps within the
+		 * same window. */
+
+		if (!irqtime || !is_idle_task(p) || cpu_is_waiting_on_io(rq))
+			delta = wallclock - mark_start;
+		else
+			delta = irqtime;
+		delta = scale_exec_time(delta, rq);
+		rq->curr_runnable_sum += delta;
+		if (!is_idle_task(p) && !exiting_task(p))
+			p->ravg.curr_window += delta;
+
+		return;
+	}
+
+	if (!p_is_curr_task) {
+		/* account_busy_for_cpu_time() = 1 so busy time needs
+		 * to be accounted to the current window. A new window
+		 * has also started, but p is not the current task, so the
+		 * window is not rolled over - just split up and account
+		 * as necessary into curr and prev. The window is only
+		 * rolled over when a new window is processed for the current
+		 * task.
+		 *
+		 * Irqtime can't be accounted by a task that isn't the
+		 * currently running task. */
+
+		if (!nr_full_windows) {
+			/* A full window hasn't elapsed, account partial
+			 * contribution to previous completed window. */
+			delta = scale_exec_time(window_start - mark_start, rq);
+			if (!exiting_task(p))
+				p->ravg.prev_window += delta;
+		} else {
+			/* Since at least one full window has elapsed,
+			 * the contribution to the previous window is the
+			 * full window (window_size). */
+			delta = scale_exec_time(window_size, rq);
+			if (!exiting_task(p))
+				p->ravg.prev_window = delta;
+		}
+		rq->prev_runnable_sum += delta;
+
+		/* Account piece of busy time in the current window. */
+		delta = scale_exec_time(wallclock - window_start, rq);
+		rq->curr_runnable_sum += delta;
+		if (!exiting_task(p))
+			p->ravg.curr_window = delta;
+
+		return;
+	}
+
+	if (!irqtime || !is_idle_task(p) || cpu_is_waiting_on_io(rq)) {
+		/* account_busy_for_cpu_time() = 1 so busy time needs
+		 * to be accounted to the current window. A new window
+		 * has started and p is the current task so rollover is
+		 * needed. If any of these three above conditions are true
+		 * then this busy time can't be accounted as irqtime.
+		 *
+		 * Busy time for the idle task or exiting tasks need not
+		 * be accounted.
+		 *
+		 * An example of this would be a task that starts execution
+		 * and then sleeps once a new window has begun. */
+
+		if (!nr_full_windows) {
+			/* A full window hasn't elapsed, account partial
+			 * contribution to previous completed window. */
+			delta = scale_exec_time(window_start - mark_start, rq);
+			if (!is_idle_task(p) && !exiting_task(p))
+				p->ravg.prev_window += delta;
+
+			delta += rq->curr_runnable_sum;
+		} else {
+			/* Since at least one full window has elapsed,
+			 * the contribution to the previous window is the
+			 * full window (window_size). */
+			delta = scale_exec_time(window_size, rq);
+			if (!is_idle_task(p) && !exiting_task(p))
+				p->ravg.prev_window = delta;
+
+		}
+		/*
+		 * Rollover for normal runnable sum is done here by overwriting
+		 * the values in prev_runnable_sum and curr_runnable_sum.
+		 * Rollover for new task runnable sum has completed by previous
+		 * if-else statement.
+		 */
+		rq->prev_runnable_sum = delta;
+
+		/* Account piece of busy time in the current window. */
+		delta = scale_exec_time(wallclock - window_start, rq);
+		rq->curr_runnable_sum = delta;
+		if (!is_idle_task(p) && !exiting_task(p))
+			p->ravg.curr_window = delta;
+
+		return;
+	}
+
+	if (irqtime) {
+		/* account_busy_for_cpu_time() = 1 so busy time needs
+		 * to be accounted to the current window. A new window
+		 * has started and p is the current task so rollover is
+		 * needed. The current task must be the idle task because
+		 * irqtime is not accounted for any other task.
+		 *
+		 * Irqtime will be accounted each time we process IRQ activity
+		 * after a period of idleness, so we know the IRQ busy time
+		 * started at wallclock - irqtime. */
+
+		BUG_ON(!is_idle_task(p));
+		mark_start = wallclock - irqtime;
+
+		/* Roll window over. If IRQ busy time was just in the current
+		 * window then that is all that need be accounted. */
+		rq->prev_runnable_sum = rq->curr_runnable_sum;
+		if (mark_start > window_start) {
+			rq->curr_runnable_sum = scale_exec_time(irqtime, rq);
+			return;
+		}
+
+		/* The IRQ busy time spanned multiple windows. Process the
+		 * busy time preceding the current window start first. */
+		delta = window_start - mark_start;
+		if (delta > window_size)
+			delta = window_size;
+		delta = scale_exec_time(delta, rq);
+		rq->prev_runnable_sum += delta;
+
+		/* Process the remaining IRQ busy time in the current window. */
+		delta = wallclock - window_start;
+		rq->curr_runnable_sum = scale_exec_time(delta, rq);
+
+		return;
+	}
+
+	BUG();
+}
+
+static int account_busy_for_task_demand(struct task_struct *p, int event)
+{
+	/* No need to bother updating task demand for exiting tasks
+	 * or the idle task. */
+	if (exiting_task(p) || is_idle_task(p))
+		return 0;
+
+	/* When a task is waking up it is completing a segment of non-busy
+	 * time. Likewise, if wait time is not treated as busy time, then
+	 * when a task begins to run or is migrated, it is not running and
+	 * is completing a segment of non-busy time. */
+	if (event == TASK_WAKE || (!walt_account_wait_time &&
+			 (event == PICK_NEXT_TASK || event == TASK_MIGRATE)))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * 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
+ * when, say, a real-time task runs without preemption for several windows at a
+ * stretch.
+ */
+static void update_history(struct rq *rq, struct task_struct *p,
+			 u32 runtime, int samples, int event)
+{
+	u32 *hist = &p->ravg.sum_history[0];
+	int ridx, widx;
+	u32 max = 0, avg, demand;
+	u64 sum = 0;
+
+	/* Ignore windows where task had no activity */
+	if (!runtime || is_idle_task(p) || exiting_task(p) || !samples)
+			goto done;
+
+	/* Push new 'runtime' value onto stack */
+	widx = walt_ravg_hist_size - 1;
+	ridx = widx - samples;
+	for (; ridx >= 0; --widx, --ridx) {
+		hist[widx] = hist[ridx];
+		sum += hist[widx];
+		if (hist[widx] > max)
+			max = hist[widx];
+	}
+
+	for (widx = 0; widx < samples && widx < walt_ravg_hist_size; widx++) {
+		hist[widx] = runtime;
+		sum += hist[widx];
+		if (hist[widx] > max)
+			max = hist[widx];
+	}
+
+	p->ravg.sum = 0;
+
+	if (walt_window_stats_policy == WINDOW_STATS_RECENT) {
+		demand = runtime;
+	} else if (walt_window_stats_policy == WINDOW_STATS_MAX) {
+		demand = max;
+	} else {
+		avg = div64_u64(sum, walt_ravg_hist_size);
+		if (walt_window_stats_policy == WINDOW_STATS_AVG)
+			demand = avg;
+		else
+			demand = max(avg, runtime);
+	}
+
+	/*
+	 * A throttled deadline sched class task gets dequeued without
+	 * changing p->on_rq. Since the dequeue decrements hmp stats
+	 * avoid decrementing it here again.
+	 *
+	 * When window is rolled over, the cumulative window demand
+	 * is reset to the cumulative runnable average (contribution from
+	 * the tasks on the runqueue). If the current task is dequeued
+	 * already, it's demand is not included in the cumulative runnable
+	 * average. So add the task demand separately to cumulative window
+	 * demand.
+	 */
+	if (!task_has_dl_policy(p) || !p->dl.dl_throttled) {
+		if (task_on_rq_queued(p))
+			fixup_cumulative_runnable_avg(rq, p, demand);
+		else if (rq->curr == p)
+			fixup_cum_window_demand(rq, demand);
+	}
+
+	p->ravg.demand = demand;
+
+done:
+	trace_walt_update_history(rq, p, runtime, samples, event);
+	return;
+}
+
+static void add_to_task_demand(struct rq *rq, struct task_struct *p,
+				u64 delta)
+{
+	delta = scale_exec_time(delta, rq);
+	p->ravg.sum += delta;
+	if (unlikely(p->ravg.sum > walt_ravg_window))
+		p->ravg.sum = walt_ravg_window;
+}
+
+/*
+ * Account cpu demand of task and/or update task's cpu demand history
+ *
+ * ms = p->ravg.mark_start;
+ * wc = wallclock
+ * ws = rq->window_start
+ *
+ * Three possibilities:
+ *
+ *	a) Task event is contained within one window.
+ *		window_start < mark_start < wallclock
+ *
+ *		ws   ms  wc
+ *		|    |   |
+ *		V    V   V
+ *		|---------------|
+ *
+ *	In this case, p->ravg.sum is updated *iff* event is appropriate
+ *	(ex: event == PUT_PREV_TASK)
+ *
+ *	b) Task event spans two windows.
+ *		mark_start < window_start < wallclock
+ *
+ *		ms   ws   wc
+ *		|    |    |
+ *		V    V    V
+ *		-----|-------------------
+ *
+ *	In this case, p->ravg.sum is updated with (ws - ms) *iff* event
+ *	is appropriate, then a new window sample is recorded followed
+ *	by p->ravg.sum being set to (wc - ws) *iff* event is appropriate.
+ *
+ *	c) Task event spans more than two windows.
+ *
+ *		ms ws_tmp			   ws  wc
+ *		|  |				   |   |
+ *		V  V				   V   V
+ *		---|-------|-------|-------|-------|------
+ *		   |				   |
+ *		   |<------ nr_full_windows ------>|
+ *
+ *	In this case, p->ravg.sum is updated with (ws_tmp - ms) first *iff*
+ *	event is appropriate, window sample of p->ravg.sum is recorded,
+ *	'nr_full_window' samples of window_size is also recorded *iff*
+ *	event is appropriate and finally p->ravg.sum is set to (wc - ws)
+ *	*iff* event is appropriate.
+ *
+ * IMPORTANT : Leave p->ravg.mark_start unchanged, as update_cpu_busy_time()
+ * depends on it!
+ */
+static void update_task_demand(struct task_struct *p, struct rq *rq,
+	     int event, u64 wallclock)
+{
+	u64 mark_start = p->ravg.mark_start;
+	u64 delta, window_start = rq->window_start;
+	int new_window, nr_full_windows;
+	u32 window_size = walt_ravg_window;
+
+	new_window = mark_start < window_start;
+	if (!account_busy_for_task_demand(p, event)) {
+		if (new_window)
+			/* If the time accounted isn't being accounted as
+			 * busy time, and a new window started, only the
+			 * previous window need be closed out with the
+			 * pre-existing demand. Multiple windows may have
+			 * elapsed, but since empty windows are dropped,
+			 * it is not necessary to account those. */
+			update_history(rq, p, p->ravg.sum, 1, event);
+		return;
+	}
+
+	if (!new_window) {
+		/* The simple case - busy time contained within the existing
+		 * window. */
+		add_to_task_demand(rq, p, wallclock - mark_start);
+		return;
+	}
+
+	/* Busy time spans at least two windows. Temporarily rewind
+	 * window_start to first window boundary after mark_start. */
+	delta = window_start - mark_start;
+	nr_full_windows = div64_u64(delta, window_size);
+	window_start -= (u64)nr_full_windows * (u64)window_size;
+
+	/* Process (window_start - mark_start) first */
+	add_to_task_demand(rq, p, window_start - mark_start);
+
+	/* Push new sample(s) into task's demand history */
+	update_history(rq, p, p->ravg.sum, 1, event);
+	if (nr_full_windows)
+		update_history(rq, p, scale_exec_time(window_size, rq),
+			       nr_full_windows, event);
+
+	/* Roll window_start back to current to process any remainder
+	 * in current window. */
+	window_start += (u64)nr_full_windows * (u64)window_size;
+
+	/* Process (wallclock - window_start) next */
+	mark_start = window_start;
+	add_to_task_demand(rq, p, wallclock - mark_start);
+}
+
+/* Reflect task activity on its demand and cpu's busy time statistics */
+void walt_update_task_ravg(struct task_struct *p, struct rq *rq,
+	     int event, u64 wallclock, u64 irqtime)
+{
+	if (walt_disabled || !rq->window_start)
+		return;
+
+	lockdep_assert_held(&rq->lock);
+
+	update_window_start(rq, wallclock);
+
+	if (!p->ravg.mark_start)
+		goto done;
+
+	update_task_demand(p, rq, event, wallclock);
+	update_cpu_busy_time(p, rq, event, wallclock, irqtime);
+
+done:
+	trace_walt_update_task_ravg(p, rq, event, wallclock, irqtime);
+
+	p->ravg.mark_start = wallclock;
+}
+
+static void reset_task_stats(struct task_struct *p)
+{
+	u32 sum = 0;
+
+	if (exiting_task(p))
+		sum = EXITING_TASK_MARKER;
+
+	memset(&p->ravg, 0, sizeof(struct ravg));
+	/* Retain EXITING_TASK marker */
+	p->ravg.sum_history[0] = sum;
+}
+
+void walt_mark_task_starting(struct task_struct *p)
+{
+	u64 wallclock;
+	struct rq *rq = task_rq(p);
+
+	if (!rq->window_start) {
+		reset_task_stats(p);
+		return;
+	}
+
+	wallclock = walt_ktime_clock();
+	p->ravg.mark_start = wallclock;
+}
+
+void walt_set_window_start(struct rq *rq)
+{
+	int cpu = cpu_of(rq);
+	struct rq *sync_rq = cpu_rq(sync_cpu);
+
+	if (likely(rq->window_start))
+		return;
+
+	if (cpu == sync_cpu) {
+		rq->window_start = 1;
+	} else {
+		raw_spin_unlock(&rq->lock);
+		double_rq_lock(rq, sync_rq);
+		rq->window_start = cpu_rq(sync_cpu)->window_start;
+		rq->curr_runnable_sum = rq->prev_runnable_sum = 0;
+		raw_spin_unlock(&sync_rq->lock);
+	}
+
+	rq->curr->ravg.mark_start = rq->window_start;
+}
+
+void walt_migrate_sync_cpu(int cpu)
+{
+	if (cpu == sync_cpu)
+		sync_cpu = smp_processor_id();
+}
+
+void walt_fixup_busy_time(struct task_struct *p, int new_cpu)
+{
+	struct rq *src_rq = task_rq(p);
+	struct rq *dest_rq = cpu_rq(new_cpu);
+	u64 wallclock;
+
+	if (!p->on_rq && p->state != TASK_WAKING)
+		return;
+
+	if (exiting_task(p)) {
+		return;
+	}
+
+	if (p->state == TASK_WAKING)
+		double_rq_lock(src_rq, dest_rq);
+
+	wallclock = walt_ktime_clock();
+
+	walt_update_task_ravg(task_rq(p)->curr, task_rq(p),
+			TASK_UPDATE, wallclock, 0);
+	walt_update_task_ravg(dest_rq->curr, dest_rq,
+			TASK_UPDATE, wallclock, 0);
+
+	walt_update_task_ravg(p, task_rq(p), TASK_MIGRATE, wallclock, 0);
+
+	/*
+	 * When a task is migrating during the wakeup, adjust
+	 * the task's contribution towards cumulative window
+	 * demand.
+	 */
+	if (p->state == TASK_WAKING &&
+	    p->last_sleep_ts >= src_rq->window_start) {
+		fixup_cum_window_demand(src_rq, -(s64)p->ravg.demand);
+		fixup_cum_window_demand(dest_rq, p->ravg.demand);
+	}
+
+	if (p->ravg.curr_window) {
+		src_rq->curr_runnable_sum -= p->ravg.curr_window;
+		dest_rq->curr_runnable_sum += p->ravg.curr_window;
+	}
+
+	if (p->ravg.prev_window) {
+		src_rq->prev_runnable_sum -= p->ravg.prev_window;
+		dest_rq->prev_runnable_sum += p->ravg.prev_window;
+	}
+
+	if ((s64)src_rq->prev_runnable_sum < 0) {
+		src_rq->prev_runnable_sum = 0;
+		WARN_ON(1);
+	}
+	if ((s64)src_rq->curr_runnable_sum < 0) {
+		src_rq->curr_runnable_sum = 0;
+		WARN_ON(1);
+	}
+
+	trace_walt_migration_update_sum(src_rq, p);
+	trace_walt_migration_update_sum(dest_rq, p);
+
+	if (p->state == TASK_WAKING)
+		double_rq_unlock(src_rq, dest_rq);
+}
+
+void walt_init_new_task_load(struct task_struct *p)
+{
+	int i;
+	u32 init_load_windows =
+			div64_u64((u64)sysctl_sched_walt_init_task_load_pct *
+                          (u64)walt_ravg_window, 100);
+	u32 init_load_pct = current->init_load_pct;
+
+	p->init_load_pct = 0;
+	memset(&p->ravg, 0, sizeof(struct ravg));
+
+	if (init_load_pct) {
+		init_load_windows = div64_u64((u64)init_load_pct *
+			  (u64)walt_ravg_window, 100);
+	}
+
+	p->ravg.demand = init_load_windows;
+	for (i = 0; i < RAVG_HIST_SIZE_MAX; ++i)
+		p->ravg.sum_history[i] = init_load_windows;
+}