commit 9e09cbceb016e7646b15b29f17c905b14a9fbab3
author Jaegeuk Kim <jaegeuk@google.com> Wed Nov 27 15:42:10 2019 -0800
committer Jaegeuk Kim <jaegeuk@google.com> Thu Jan 23 19:39:52 2020 +0000
tree 5c28cb84965d9c10f79ae4f19a71f17453265556
parent 81303e4c8f3889857925d4253a8a134d088a13a0

rootdir: init.rc to limit discard size to 128MB

In any case, UFS storage suffers from long discard latency.

Bug: 148209614
Change-Id: Iaa8ef6eb862934af43254bd10873a12c3d34e926
Merged-In: Iaa8ef6eb862934af43254bd10873a12c3d34e926
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>

rootdir/init.rc

diff --git a/rootdir/init.rc b/rootdir/init.rc
index 0fa9feb..e898d4d 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -682,6 +682,11 @@
     write /sys/fs/f2fs/${dev.mnt.blk.data}/cp_interval 200
     write /sys/fs/f2fs/${dev.mnt.blk.data}/gc_urgent_sleep_time 50
 
+    # limit discard size to 128MB in order to avoid long IO latency
+    # for filesystem tuning first (dm or sda)
+    # Note that, if dm-<num> is used, sda/mmcblk0 should be tuned in vendor/init.rc
+    write /sys/devices/virtual/block/${dev.mnt.blk.data}/queue/discard_max_bytes 134217728
+
     # Permissions for System Server and daemons.
     chown radio system /sys/android_power/state
     chown radio system /sys/android_power/request_state