From cc60f0790f27186b8b22cf4bac307b53202601b8 Mon Sep 17 00:00:00 2001
From: Joonwoo Park <joonwoop@codeaurora.org>
Date: Wed, 21 Sep 2016 14:51:51 -0700
Subject: [PATCH] sched: constrain HMP scheduler tunable range with in better
 way

HMP scheduler tunables can be constrained via extra1 and extra2 of
ctl_table.  Having valid range in the sysctl table gives clearer
view of tunable's range.

Also add range for sched_select_prev_cpu_us so we can avoid invalid
value configuration of that tunable.

CRs-fixed: 1056910
Change-Id: I09fcc019133f4d37b7be3287da8e0733e40fc0ac
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
---
 kernel/sched/hmp.c | 26 ++++----------------------
 kernel/sysctl.c    | 23 +++++++++++++++++++++++
 2 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/kernel/sched/hmp.c b/kernel/sched/hmp.c
index 5002619961ce..eb97119d7a98 100644
--- a/kernel/sched/hmp.c
+++ b/kernel/sched/hmp.c
@@ -1499,28 +1499,10 @@ int sched_hmp_proc_update_handler(struct ctl_table *table, int write,
 	if (write && (old_val == *data))
 		goto done;
 
-	/*
-	 * Special handling for sched_freq_aggregate_threshold_pct
-	 * which can be greater than 100. Use 1000 as an upper bound
-	 * value which works for all practical use cases.
-	 */
-	if (data == &sysctl_sched_freq_aggregate_threshold_pct) {
-		if (*data > 1000) {
-			*data = old_val;
-			ret = -EINVAL;
-			goto done;
-		}
-	} else if (data != &sysctl_sched_select_prev_cpu_us) {
-		/*
-		 * all tunables other than sched_select_prev_cpu_us are
-		 * in percentage.
-		 */
-		if (sysctl_sched_downmigrate_pct >
-		    sysctl_sched_upmigrate_pct || *data > 100) {
-			*data = old_val;
-			ret = -EINVAL;
-			goto done;
-		}
+	if (sysctl_sched_downmigrate_pct > sysctl_sched_upmigrate_pct) {
+		*data = old_val;
+		ret = -EINVAL;
+		goto done;
 	}
 
 	/*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 07fef40d1274..dad3324e7372 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -130,6 +130,9 @@ static int one_hundred = 100;
 #ifdef CONFIG_PRINTK
 static int ten_thousand = 10000;
 #endif
+#ifdef CONFIG_SCHED_HMP
+static int one_thousand = 1000;
+#endif
 
 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
@@ -336,6 +339,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= sched_hmp_proc_update_handler,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
 	},
 	{
 		.procname	= "sched_spill_nr_run",
@@ -351,6 +356,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= sched_hmp_proc_update_handler,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
 	},
 	{
 		.procname	= "sched_downmigrate",
@@ -358,6 +365,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= sched_hmp_proc_update_handler,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
 	},
 	{
 		.procname	= "sched_init_task_load",
@@ -365,6 +374,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= sched_hmp_proc_update_handler,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
 	},
 	{
 		.procname	= "sched_select_prev_cpu_us",
@@ -372,6 +383,7 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler   = sched_hmp_proc_update_handler,
+		.extra1		= &zero,
 	},
 	{
 		.procname       = "sched_enable_colocation",
@@ -397,6 +409,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler   = sched_hmp_proc_update_handler,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
 	},
 	{
 		.procname	= "sched_big_waker_task_load",
@@ -404,6 +418,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler   = sched_hmp_proc_update_handler,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
 	},
 	{
 		.procname       = "sched_enable_thread_grouping",
@@ -440,6 +456,13 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= sched_hmp_proc_update_handler,
+		.extra1		= &zero,
+		/*
+		 * Special handling for sched_freq_aggregate_threshold_pct
+		 * which can be greater than 100. Use 1000 as an upper bound
+		 * value which works for all practical use cases.
+		 */
+		.extra2		= &one_thousand,
 	},
 	{
 		.procname	= "sched_boost",