platform_system_core/lmkd
Suren Baghdasaryan d4a29903c0 lmkd: Add command to get number of kills
Intrduce LMK_GETKILLCNT command for ActivityManager to get the number of
kills from lmkd.

Bug: 117126077
Test: used lmkd_unit_test to verify correct reporting
Change-Id: I09c720a7176b4df95efc544177cd2694f8d791be
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-10-24 17:18:32 +00:00
..
include lmkd: Add command to get number of kills 2018-10-24 17:18:32 +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: Add command to get number of kills 2018-10-24 17:18:32 +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

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