From f21f68411bb16f92712a3b97c52cb4bcac54b367 Mon Sep 17 00:00:00 2001
From: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
Date: Tue, 23 May 2023 01:02:33 +0600
Subject: [PATCH] sdm660-common: Enforce read-ahead to be 128 KB after boot

Google has mentioned that 512 KB performs worse under heavy memory pressure.
Therefore, hardcode 128 KB read-ahead for all which is optimal.
Also, remove the unused block paths.

Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
Signed-off-by: pix106 <sbordenave@gmail.com>
---
 rootdir/bin/init.qcom.post_boot.sh | 22 ++++------------------
 rootdir/etc/init.qcom.rc           |  7 +++++++
 2 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/rootdir/bin/init.qcom.post_boot.sh b/rootdir/bin/init.qcom.post_boot.sh
index 6b9de4d6..12f6fa6b 100644
--- a/rootdir/bin/init.qcom.post_boot.sh
+++ b/rootdir/bin/init.qcom.post_boot.sh
@@ -835,26 +835,12 @@ function configure_zram_parameters() {
 }
 
 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
-        echo 128 > /sys/block/mmcblk0/bdi/read_ahead_kb
-        echo 128 > /sys/block/mmcblk0rpmb/bdi/read_ahead_kb
-        for dm in $dmpts; do
-            echo 128 > $dm
-        done
-    else
-        echo 512 > /sys/block/mmcblk0/bdi/read_ahead_kb
-        echo 512 > /sys/block/mmcblk0rpmb/bdi/read_ahead_kb
-        for dm in $dmpts; do
-            echo 512 > $dm
-        done
-    fi
+    echo 128 > /sys/block/mmcblk0/bdi/read_ahead_kb
+    for dm in $dmpts; do
+        echo 128 > $dm
+    done
 }
 
 function disable_core_ctl() {
diff --git a/rootdir/etc/init.qcom.rc b/rootdir/etc/init.qcom.rc
index 6c1d23e8..953684cb 100755
--- a/rootdir/etc/init.qcom.rc
+++ b/rootdir/etc/init.qcom.rc
@@ -437,6 +437,13 @@ on property:persist.vendor.sys.rawdump_copy=0
 
 on property:sys.boot_completed=1
     write /dev/kmsg "Boot completed "
+    #Reset read ahead to 128kb
+    write /sys/block/dm-0/queue/read_ahead_kb 128
+    write /sys/block/dm-1/queue/read_ahead_kb 128
+    write /sys/block/dm-2/queue/read_ahead_kb 128
+    write /sys/block/dm-3/queue/read_ahead_kb 128
+    write /sys/block/dm-4/queue/read_ahead_kb 128
+    write /sys/block/mmcblk0/queue/read_ahead_kb 128
     #WDSP FW boot sysfs node used by STHAL
     chown media audio /sys/kernel/wdsp0/boot
     chown media audio /sys/kernel/wcd_cpe0/fw_name