commit | 65c1b5dcc5bd5795ffbe6dc8e223bd8cfe01ddbb | [log] [tgz] |
---|---|---|
author | Carlos Galo <carlosgalo@google.com> | Wed Mar 27 22:27:40 2024 +0000 |
committer | Carlos Galo <carlosgalo@google.com> | Tue Apr 02 22:25:36 2024 +0000 |
tree | 457f1b5262fd1a812b824baabe2efc2b1a107cab | |
parent | 81a7c210876daff7ed0c3f8f1b27039f99f0aed7 [diff] |
Add boot completed cmd to LMKD Add new command to allow for post-boot actions to occur. This will allow for the MemEventListener to start after the BPF files are loaded, removing the need to stall during boot-up until they are loaded in the device. Test: Verified memevent listener initialized post-boot Test: Verified LMKD no longer stalls until BPF progs are loaded Bug: 331008250 Bug: 244232958 Change-Id: I55f97b41349ea7693cff81b1170d33712b820292 Signed-off-by: Carlos Galo <carlosgalo@google.com>
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.
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.
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
ro.lmk.swap_free_low_percentage
: level of free swap as a percentage of the total swap space used as a threshold to consider the system as swap space starved. Default for low-RAM devices = 10, for high-end devices = 20
ro.lmk.thrashing_limit
: number of workingset refaults as a percentage of the file-backed pagecache size used as a threshold to consider system thrashing its pagecache. Default for low-RAM devices = 30, for high-end devices = 100
ro.lmk.thrashing_limit_decay
: thrashing threshold decay expressed as a percentage of the original threshold used to lower the threshold when system does not recover even after a kill. Default for low-RAM devices = 50, for high-end devices = 10
ro.lmk.psi_partial_stall_ms
: partial PSI stall threshold in milliseconds for triggering low memory notification. Default for low-RAM devices = 200, for high-end devices = 70
ro.lmk.psi_complete_stall_ms
: complete PSI stall threshold in milliseconds for triggering critical memory notification. Default = 700
ro.lmk.pressure_after_kill_min_score
: min oom_adj_score score threshold for cycle after kill used to allow blocking of killing critical processes when not enough memory was freed in a kill cycle. Default score = 0.
ro.lmk.direct_reclaim_threshold_ms
: direct reclaim duration threshold in milliseconds to consider the system as stuck in direct reclaim. Default = 0 (disabled)
lmkd will set the following Android properties according to current system configurations:
sys.lmk.minfree_levels
: minfree:oom_adj_score pairs, delimited by comma
sys.lmk.reportkills
: whether or not it supports reporting process kills to clients. Test app should check this property before testing low memory kill notification. Default will be unset.