platform_system_core/lmkd
Suren Baghdasaryan 818b59b229 lmkd: Fix usage of ro.lmk.kill_heaviest_task property
lmkd should use ro.lmk.kill_heaviest_task property to select between
algorithms for victim selection. Set ro.lmk.kill_heaviest_task default
value to false in order to keep it compatible with previous versions
of lmkd (killing the heaviest task is a new mechanism).

Change-Id: I78d2dc79d9c54e636c26665605518d9c87b535b3
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-04-13 23:24:24 +00:00
..
include lmkd: Introduce liblmkd_utils for communicating with lmkd process 2018-03-09 11:18:53 -08:00
tests lmkd: test: access /sys/module/lowmemorykiller/ as u:r:shell:s0 2018-04-03 14:41:11 +00:00
Android.bp lmkd: only mlockall() if enabled 2018-04-03 14:41:26 +00:00
liblmkd_utils.c lmkd: Introduce liblmkd_utils for communicating with lmkd process 2018-03-09 11:18:53 -08:00
lmkd.c lmkd: Fix usage of ro.lmk.kill_heaviest_task property 2018-04-13 23:24:24 +00:00
lmkd.rc Enable hidepid=2 on /proc 2015-11-09 09:08:46 -08:00
OWNERS Add lmkd/OWNERS. 2017-12-08 16:12:58 -08:00
README.md lmkd: Add lmkd README file 2018-04-13 21:36:44 +00:00

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.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