History

Srinivas Paladugu 3eb20bc954 lmkd: increase the soft limit for keyboard lmkd sets the soft limit parameters for Go devices. The limit for apps in the perceptible group is set to 16M. However this limit is not sufficient for the keyboard app to prevent pages from being re-claimed quickly. The mem usage of the keyboard app is around 55M most cases with some occasional spikes to 70-80M. Increasing the limit to 64M improves the warm startup latency for keyboard. It is still lower than the limits set for foreground and visible apps. Test: Go device (1G) Bug: 117517805 Merged-In: Id50e49327cfd76126e41ef6503971845f29196af Change-Id: Id50e49327cfd76126e41ef6503971845f29196af		2018-10-16 18:58:01 +00:00
..
include	lmkd: Implement pid purge command to clear old pids when zygote restarts	2018-10-15 16:22:17 +00:00
tests	lmkd: rate-limit and cleanup failed kill reports	2018-09-06 01:59:49 +00:00
Android.bp	lmkd: Add meminfo logging after each kill for easy troubleshooting	2018-08-10 14:21:31 -07:00
event.logtags	lmkd: Add meminfo logging after each kill for easy troubleshooting	2018-08-10 14:21:31 -07:00
liblmkd_utils.c	lmkd: Introduce liblmkd_utils for communicating with lmkd process	2018-03-09 11:18:53 -08:00
lmkd.c	lmkd: increase the soft limit for keyboard	2018-10-16 18:58:01 +00:00
lmkd.rc	lmkd: limit capability set to minimum	2018-04-16 14:51:56 -07:00
OWNERS	Add lmkd/OWNERS.	2017-12-08 16:12:58 -08:00
README.md	lmkd: Introduce support for legacy kill algorithm that uses minfree levels	2018-04-17 01:42:06 +00:00
statslog.c	Fix the stats log in lmkd	2018-05-03 16:04:27 -07:00
statslog.h	Read memory stats from /proc/pid/stat file.	2018-10-10 22:23:25 +00:00

README.md

Android Low Memory Killer Daemon

Introduction

Android Low Memory Killer Daemon (lmkd) is a process monitoring memory state of a running Android system and reacting to high memory pressure by killing the least essential process(es) to keep system performing at acceptable levels.

Background

Historically on Android systems memory monitoring and killing of non-essential processes was handled by a kernel lowmemorykiller driver. Since Linux Kernel 4.12 the lowmemorykiller driver has been removed and instead userspace lmkd daemon performs these tasks.

Android Properties

lmkd can be configured on a particular system using the following Android properties:

ro.config.low_ram: choose between low-memory vs high-performance device. Default = false.

ro.lmk.use_minfree_levels: use free memory and file cache thresholds for making decisions when to kill. This mode works the same way kernel lowmemorykiller driver used to work. Default = false

ro.lmk.low: min oom_adj score for processes eligible to be killed at low vmpressure level. Default = 1001 (disabled)

ro.lmk.medium: min oom_adj score for processes eligible to be killed at medium vmpressure level. Default = 800 (non-essential processes)

ro.lmk.critical: min oom_adj score for processes eligible to be killed at critical vmpressure level. Default = 0 (all processes)

ro.lmk.critical_upgrade: enables upgrade to critical level. Default = false

ro.lmk.upgrade_pressure: max mem_pressure at which level will be upgraded because system is swapping too much. Default = 100 (disabled)

ro.lmk.downgrade_pressure: min mem_pressure at which vmpressure event will be ignored because enough free memory is still available. Default = 100 (disabled)

ro.lmk.kill_heaviest_task: kill heaviest eligible task (best decision) vs. any eligible task (fast decision). Default = false

ro.lmk.kill_timeout_ms: duration in ms after a kill when no additional kill will be done, Default = 0 (disabled)

ro.lmk.debug: enable lmkd debug logs, Default = false