#=============================================================================
# Copyright (c) 2020-2021 Qualcomm Technologies, Inc.
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# Confidential and Proprietary - Qualcomm Technologies, Inc.
#
# Copyright (c) 2012-2013, 2016-2020, The Linux Foundation. All rights reserved.
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#=============================================================================

function configure_zram_parameters() {
	MemTotalStr=`cat /proc/meminfo | grep MemTotal`
	MemTotal=${MemTotalStr:16:8}

	# Zram disk - 75% for < 2GB devices .
	# For >2GB devices, size = 50% of RAM size. Limit the size to 4GB.

	let RamSizeGB="( $MemTotal / 1048576 ) + 1"
	diskSizeUnit=M
	if [ $RamSizeGB -le 2 ]; then
		let zRamSizeMB="( $RamSizeGB * 1024 ) * 3 / 4"
	else
		let zRamSizeMB="( $RamSizeGB * 1024 ) / 2"
	fi

	# use MB avoid 32 bit overflow
	if [ $zRamSizeMB -gt 4096 ]; then
		let zRamSizeMB=4096
	fi

	if [ -f /sys/block/zram0/disksize ]; then
		if [ -f /sys/block/zram0/use_dedup ]; then
			echo 1 > /sys/block/zram0/use_dedup
		fi
		echo "$zRamSizeMB""$diskSizeUnit" > /sys/block/zram0/disksize

		# ZRAM may use more memory than it saves if SLAB_STORE_USER
		# debug option is enabled.
		if [ -e /sys/kernel/slab/zs_handle ]; then
			echo 0 > /sys/kernel/slab/zs_handle/store_user
		fi
		if [ -e /sys/kernel/slab/zspage ]; then
			echo 0 > /sys/kernel/slab/zspage/store_user
		fi

		mkswap /dev/block/zram0
		swapon /dev/block/zram0 -p 32758
	fi
}

function configure_read_ahead_kb_values() {
	MemTotalStr=`cat /proc/meminfo | grep MemTotal`
	MemTotal=${MemTotalStr:16:8}

	dmpts=$(ls /sys/block/*/queue/read_ahead_kb | grep -e dm -e mmc)

	# Set 128 for <= 3GB &
	# set 512 for >= 4GB targets.
	if [ $MemTotal -le 3145728 ]; then
		ra_kb=128
	else
		ra_kb=512
	fi
	if [ -f /sys/block/mmcblk0/bdi/read_ahead_kb ]; then
		echo $ra_kb > /sys/block/mmcblk0/bdi/read_ahead_kb
	fi
	if [ -f /sys/block/mmcblk0rpmb/bdi/read_ahead_kb ]; then
		echo $ra_kb > /sys/block/mmcblk0rpmb/bdi/read_ahead_kb
	fi
	for dm in $dmpts; do
		echo $ra_kb > $dm
	done
}

function configure_memory_parameters() {
	# Set Memory parameters.

	# Set swappiness to 100 for all targets
	echo 100 > /proc/sys/vm/swappiness

	# Disable wsf for all targets beacause we are using efk.
	# wsf Range : 1..1000 So set to bare minimum value 1.
	echo 1 > /proc/sys/vm/watermark_scale_factor
	configure_zram_parameters
	configure_read_ahead_kb_values

	#Spawn 2 kswapd threads which can help in fast reclaiming of pages
	echo 2 > /proc/sys/vm/kswapd_threads
}