From 4a2c606e12a7f156786ed2b86c9a491bdc2dd89d Mon Sep 17 00:00:00 2001
From: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Date: Tue, 14 Sep 2021 01:15:03 -0700
Subject: [PATCH] sched/walt: Improve the scheduler

This change is for general scheduler improvement.

Change-Id: I7e2f06b0f93d6c3c2cc439f895083f4b7cb96212
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
---
 kernel/sched/walt/sysctl.c  | 10 ++++++++++
 kernel/sched/walt/walt.h    |  1 +
 kernel/sched/walt/walt_lb.c |  7 +++++++
 3 files changed, 18 insertions(+)

diff --git a/kernel/sched/walt/sysctl.c b/kernel/sched/walt/sysctl.c
index 96bb39bfe91d..724a3849e4df 100644
--- a/kernel/sched/walt/sysctl.c
+++ b/kernel/sched/walt/sysctl.c
@@ -64,6 +64,7 @@ unsigned int sysctl_sched_sync_hint_enable = 1;
 unsigned int sysctl_sched_bug_on_rt_throttle;
 unsigned int sysctl_panic_on_walt_bug;
 unsigned int sysctl_sched_suppress_region2;
+unsigned int sysctl_sched_skip_sp_newly_idle_lb;
 
 /* range is [1 .. INT_MAX] */
 static int sysctl_task_read_pid = 1;
@@ -732,6 +733,15 @@ struct ctl_table walt_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 	},
+	{
+		.procname       = "sched_skip_sp_newly_idle_lb",
+		.data           = &sysctl_sched_skip_sp_newly_idle_lb,
+		.maxlen         = sizeof(unsigned int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
 	{
 		.procname       = "panic_on_walt_bug",
 		.data           = &sysctl_panic_on_walt_bug,
diff --git a/kernel/sched/walt/walt.h b/kernel/sched/walt/walt.h
index 64c097f92ab3..dd335d0cc299 100644
--- a/kernel/sched/walt/walt.h
+++ b/kernel/sched/walt/walt.h
@@ -288,6 +288,7 @@ extern unsigned int sysctl_walt_low_latency_task_threshold; /* disabled by defau
 extern unsigned int sysctl_sched_sync_hint_enable;
 extern unsigned int sysctl_sched_bug_on_rt_throttle;
 extern unsigned int sysctl_sched_suppress_region2;
+extern unsigned int sysctl_sched_skip_sp_newly_idle_lb;
 extern struct ctl_table walt_table[];
 extern struct ctl_table walt_base_table[];
 extern void walt_tunables(void);
diff --git a/kernel/sched/walt/walt_lb.c b/kernel/sched/walt/walt_lb.c
index 29830f65a90c..f8adcce301bd 100644
--- a/kernel/sched/walt/walt_lb.c
+++ b/kernel/sched/walt/walt_lb.c
@@ -690,6 +690,13 @@ static void walt_newidle_balance(void *unused, struct rq *this_rq,
 		busy_cpu = walt_lb_find_busiest_cpu(this_cpu,
 				&cpu_array[order_index][cluster]);
 
+		if (sysctl_sched_skip_sp_newly_idle_lb) {
+			if (busy_cpu == -1 &&
+				((order_index == 0 && cluster > 0) ||
+				(order_index == 2 && cluster > 0 && !help_min_cap)))
+				break;
+		}
+
 		/* we got the busy/src cpu here. */
 		if (busy_cpu != -1 || this_rq->nr_running > 0)
 			break;