This is nohang config file.
Lines starting with #, tabs and spaces are comments.
Lines starting with @ contain optional parameters.
All values are case sensitive.
Be careful: nohang doesn't forbid you to shoot yourself in the foot.
The configuration includes the following sections:
1. Common zram settings
2. Common PSI settings
3. Poll rate
4. Warnings and notifications
5. Soft threshold
6. Hard threshold
7. Customize victim selection: adjusting badness of processes
8. Customize soft corrective actions
9. Misc settings
10. Verbosity, debug, logging
Just read the description of the parameters and edit the values.
Please restart the program after editing the config.
TODO: improve descriptions
###############################################################################
1. Common zram settings
Key: zram_checking_enabled
Description:
Type: boolean
Valid values: True | False
Default value: False
zram_checking_enabled = False
###############################################################################
2. Common PSI settings
Key: psi_checking_enabled
Description:
Type: boolean
Valid values: True | False
Default value: False
psi_checking_enabled = False
Key: psi_path
Description:
Type: string
Valid values: any string
Default value: /proc/pressure/memory
psi_path = /proc/pressure/memory
Key: psi_metrics
Description:
Type: string
Valid values: some_avg10, some_avg60, some_avg300,
full_avg10, full_avg60, full_avg300
Default value: some_avg10
psi_metrics = some_avg10
Key: psi_excess_duration
Description:
Type: float
Valid values: >= 0
Default value: 30
psi_excess_duration = 30
Key: psi_post_action_delay
Description:
Type: float
Valid values: >= 10
Default value: 20
psi_post_action_delay = 20
###############################################################################
3. Poll rate
Key: fill_rate_mem
Description:
Type: float
Valid values: >= 100
Default value: 6000
fill_rate_mem = 6000
Key: fill_rate_swap
Description:
Type: float
Valid values: >= 100
Default value: 2000
fill_rate_swap = 2000
Key: fill_rate_zram
Description:
Type: float
Valid values: >= 100
Default value: 4000
fill_rate_zram = 4000
Key: max_sleep
Description:
Type: float
Valid values: >= 0.01 and >= min_sleep
Default value: 3
max_sleep = 3
Key: min_sleep
Description:
Type: float
Valid values: >= 0.01 and <= max_sleep
Default value: 0.1
min_sleep = 0.1
###############################################################################
4. Warnings and notifications
4.1. GUI notifications after corrective actions
Key: post_action_gui_notifications
Description:
Type: boolean
Valid values: True | False
Default value: False
post_action_gui_notifications = True
Key: hide_corrective_action_type
Description:
Type: boolean
Valid values: True | False
Default value: False
hide_corrective_action_type = False
4.2. Low memory warnings
Key: low_memory_warnings_enabled
Description:
Type: boolean
Valid values: True | False
Default value: False
low_memory_warnings_enabled = True
Key: warning_exe
Description:
Type: string
Valid values: any string
Default value: (empty string)
warning_exe =
Key: warning_threshold_min_mem
Description:
Type: float (with % or M)
Valid values: from the range [0; 100] %
Default value: 20 %
warning_threshold_min_mem = 20 %
Key: warning_threshold_min_swap
Description:
Type: float (with % or M)
Valid values: [0; 100] % or >= 0 M
Default value: 20 %
warning_threshold_min_swap = 25 %
Key: warning_threshold_max_zram
Description:
Type: float (with % or M)
Valid values: from the range [0; 100] %
Default value: 45 %
warning_threshold_max_zram = 45 %
Key: warning_threshold_max_psi
Description:
Type: float
Valid values: from the range [0; 100]
Default value: 10
warning_threshold_max_psi = 10
Key: min_post_warning_delay
Description:
Type: float
Valid values: >= 1
Default value: 60
min_post_warning_delay = 60
Key: env_cache_time
Description:
Type: float
Valid values: >= 0
Default value: 300
env_cache_time = 300
###############################################################################
5. Soft threshold (thresholds for sending the SIGTERM signal or
implementing other soft corrective action)
Key: soft_threshold_min_mem
Description:
Type: float (with % or M)
Valid values: from the range [0; 50] %
Default value: 5 %
soft_threshold_min_mem = 7 %
Key: soft_threshold_min_swap
Description:
Type: float (with % or M)
Valid values: [0; 100] % or >= 0 M
Default value: 10 %
soft_threshold_min_swap = 14 %
Key: soft_threshold_max_zram
Description:
Type: float (with % or M)
Valid values: from the range [10; 90] %
Default value: 55 %
soft_threshold_max_zram = 55 %
Key: soft_threshold_max_psi
Description:
Type: float
Valid values: from the range [5; 100]
Default value: 40
soft_threshold_max_psi = 40
###############################################################################
6. Hard threshold (thresholds for sending the SIGKILL signal)
Key: hard_threshold_min_mem
Description:
Type: float (with % or M)
Valid values: from the range [0; 50] %
Default value: 2 %
hard_threshold_min_mem = 2 %
Key: hard_threshold_min_swap
Description:
Type: float (with % or M)
Valid values: [0; 100] % or >= 0 M
Default value: 4 %
hard_threshold_min_swap = 4 %
Key: hard_threshold_max_zram
Description:
Type: float (with % or M)
Valid values: from the range [10; 90] %
Default value: 60 %
hard_threshold_max_zram = 60 %
Key: hard_threshold_max_psi
Description:
Type: float
Valid values: from the range [5; 100]
Default value: 90
hard_threshold_max_psi = 90
###############################################################################
7. Customize victim selection: adjusting badness of processes
7.1. Ignore positive oom_score_adj
Key: ignore_positive_oom_score_adj
Description:
Type: boolean
Valid values: True | False
Default value: False
ignore_positive_oom_score_adj = False
7.2.1. Matching process names with RE patterns change their badness
Syntax:
@BADNESS_ADJ_RE_NAME badness_adj /// RE_pattern
New badness value will be += badness_adj
It is possible to compare multiple patterns
with different badness_adj values.
Example:
@BADNESS_ADJ_RE_NAME 200 /// ^Web Content$
7.2.2. Matching CGroup_v1-line with RE patterns
@BADNESS_ADJ_RE_CGROUP_V1 -50 /// ^/system\.slice/
@BADNESS_ADJ_RE_CGROUP_V1 50 /// /foo\.service$
@BADNESS_ADJ_RE_CGROUP_V1 -50 /// ^/user\.slice/
7.2.3. Matching CGroup_v2-line with RE patterns
@BADNESS_ADJ_RE_CGROUP_V2 100 /// ^/workload
7.2.4. Matching eUIDs with RE patterns
@BADNESS_ADJ_RE_UID -100 /// ^0$
7.2.5. Matching /proc/[pid]/exe realpath with RE patterns
Example:
@BADNESS_ADJ_RE_REALPATH 900 /// ^(/usr/bin/stress|/usr/bin/stress-ng)$
7.2.6. Matching cwd with RE patterns
@BADNESS_ADJ_RE_CWD 200 /// ^/home/
7.2.7. Matching cmdlines with RE patterns
WARNING: using this option can greatly slow down the search for a victim
in conditions of heavily swapping.
Prefer Chromium tabs and Electron-based apps
@BADNESS_ADJ_RE_CMDLINE 200 /// --type=renderer
Prefer Firefox tabs (Web Content and WebExtensions)
@BADNESS_ADJ_RE_CMDLINE 100 /// -appomni
@BADNESS_ADJ_RE_CMDLINE -200 /// ^/usr/lib/virtualbox
7.2.8. Matching environ with RE patterns
WARNING: using this option can greatly slow down the search for a victim
in conditions of heavy swapping.
@BADNESS_ADJ_RE_ENVIRON 100 /// USER=user
Note that you can control badness also via systemd units via
OOMScoreAdjust, see
www.freedesktop.org/software/systemd/man/systemd.exec.html#OOMScoreAdjust=
###############################################################################
8. Customize soft corrective actions
Run the command instead of sending a signal with at soft corrective action
if the victim's name or cgroup matches the regular expression.
Syntax:
KEY REGEXP SEPARATOR COMMAND
@SOFT_ACTION_RE_NAME ^foo$ /// kill -USR1 $PID
@SOFT_ACTION_RE_CGROUP_V1 ^/system\.slice/ /// systemctl restart $SERVICE
@SOFT_ACTION_RE_CGROUP_V2 /foo\.service$ /// systemctl restart $SERVICE
$PID will be replaced by process PID.
$NAME will be replaced by process name.
$SERVICE will be replaced by .service if it exists (overwise it will be
relpaced by empty line)
###############################################################################
9. Misc settings
Key: max_soft_exit_time
Description:
Type: float
Valid values: >= 0.1
Default value: 10
max_soft_exit_time = 10
Key: post_kill_exe
Description:
Type: string
Valid values: any string
Default value: (empty string)
post_kill_exe =
Key: min_badness
Description:
Type: integer
Valid values: >= 1
Default value: 1
min_badness = 1
Key: post_soft_action_delay
Description:
Type: float
Valid values: >= 0.1
Default value: 3
post_soft_action_delay = 3
Key: post_zombie_delay
Description:
Type: float
Valid values: >= 0
Default value: 0.1
post_zombie_delay = 0.1
Key: victim_cache_time
Description:
Type: float
Valid values: >= 0
Default value: 10
victim_cache_time = 10
Key: exe_timeout
Description:
Type: float
Valid values: >= 0.1
Default value: 20
exe_timeout = 20
###############################################################################
10. Verbosity, debug, logging
Key: print_config_at_startup
Description:
Type: boolean
Valid values: True | False
Default value: False
print_config_at_startup = False
Key: print_mem_check_results
Description:
Type: boolean
Valid values: True | False
Default value: False
print_mem_check_results = False
Key: min_mem_report_interval
Description:
Type: float
Valid values: >= 0
Default value: 60
min_mem_report_interval = 60
Key: print_proc_table
Description:
Type: boolean
Valid values: True | False
Default value: False
print_proc_table = False
Key: extra_table_info
Description:
WARNING: using "cmdline" or "environ" keys can greatly slow down
the search for a victim in conditions of heavy swapping.
Type: string
Valid values: None, cgroup_v1, cgroup_v2, realpath,
cwd, cmdline, environ
Default value: None
extra_table_info = None
Key: print_victim_status
Description:
Type: boolean
Valid values: True | False
Default value: True
print_victim_status = True
Key: print_victim_cmdline
Description:
Type: boolean
Valid values: True | False
Default value: False
print_victim_cmdline = False
Key: max_victim_ancestry_depth
Description:
Type: integer
Valid values: >= 1
Default value: 3
max_victim_ancestry_depth = 3
Key: print_statistics
Description:
Type: boolean
Valid values: True | False
Default value: True
print_statistics = True
Key: debug_psi
Description:
Type: boolean
Valid values: True | False
Default value: False
debug_psi = False
Key: debug_gui_notifications
Description:
Type: boolean
Valid values: True | False
Default value: False
debug_gui_notifications = False
Key: debug_sleep
Description:
Type: boolean
Valid values: True | False
Default value: False
debug_sleep = False
Key: debug_threading
Description:
Type: boolean
Valid values: True | False
Default value: False
debug_threading = False
Key: separate_log
Description:
Type: boolean
Valid values: True | False
Default value: False
separate_log = False
###############################################################################
Use cases, feature requests and any questions are welcome:
https://github.com/hakavlad/nohang/issues