wenchao-hao
/
lmkd
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
71 Commits 2 Branches 0 Tags 2.3 MiB
C++ 88.4%
C 11.6%
Go to file
Suren Baghdasaryan 3bac7a1daf lmkd: Switch to using /proc/meminfo to have access to file cache size 
Current mechanism of getting system memory state by using sysinfo()
is not enough because it does not provide information about file cache
size which is needed to correctly assess memory state. Switch to using
data from /proc/meminfo that includes information provided by sysinfo()
and file cache size in addition to that.


Bug: 77299493
Bug: 75322373
Merged-In: I16106fc4f9254f17f776803e60502b7b6474e1b7
Change-Id: I16106fc4f9254f17f776803e60502b7b6474e1b7
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
 		2018-04-15 10:03:05 +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
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
liblmkd_utils.c lmkd: Introduce liblmkd_utils for communicating with lmkd process 2018-03-09 11:18:53 -08:00
lmkd.c lmkd: Switch to using /proc/meminfo to have access to file cache size 2018-04-15 10:03:05 +00:00
lmkd.rc Enable hidepid=2 on /proc 2015-11-09 09:08:46 -08:00

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.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