NAME

       earlyoom - Early OOM Daemon

SYNOPSIS

       earlyoom [OPTION]...

DESCRIPTION

       The  oom-killer generally has a bad reputation among Linux users.  One may have to sit in front of an un‐
       responsive system, listening to the grinding disk for minutes, and press the reset button to quickly  get
       back to what one was doing after running out of patience.

       earlyoom checks the amount of available memory and free swap up to 10 times a second (less often if there
       is a lot of free memory).  If both memory and swap are below 10%, it will kill the largest process (high‐
       est oom_score).  The percentage value is configurable via command line arguments.

       If  there  is a failure when trying to kill a process, earlyoom sleeps for 1 second to limit log spam due
       to recurring errors.

OPTIONS

   -m PERCENT[,KILL_PERCENT]
       set available memory minimum to PERCENT of total (default 10 %).

       earlyoom starts sending SIGTERM once both memory and swap are below their respective PERCENT setting.  It
       sends SIGKILL once both are below their respective KILL_PERCENT setting (default PERCENT/2).

       Use the same value for PERCENT and KILL_PERCENT if you always want to use SIGKILL.

       Examples:

              earlyoom              # sets PERCENT=10, KILL_PERCENT=5
              earlyoom -m 30        # sets PERCENT=30, KILL_PERCENT=15
              earlyoom -m 20,18     # sets PERCENT=20, KILL_PERCENT=18

   -s PERCENT[,KILL_PERCENT]
       set free swap minimum to PERCENT of total (default 10 %).  Send SIGKILL if at or below KILL_PERCENT  (de‐
       fault PERCENT/2), otherwise SIGTERM.

       You  can  use  -s 100 to have earlyoom effectively ignore swap usage: Processes are killed once available
       memory drops below the configured minimum, no matter how much swap is free.

       Use the same value for PERCENT and KILL_PERCENT if you always want to use SIGKILL.

   -M SIZE[,KILL_SIZE]
       As an alternative to specifying a percentage of total memory, -M sets the  available  memory  minimum  to
       SIZE KiB.  The value is internally converted to a percentage.  If you pass both -M and -m, the lower val‐
       ue is used.  Example: Reserve 10% of RAM but at most 1 GiB:

              earlyoom -m 10 -M 1048576

       earlyoom sends SIGKILL if at or below KILL_SIZE (default SIZE/2), otherwise SIGTERM.

   -S SIZE[,KILL_SIZE]
       As  an  alternative  to specifying a percentage of total swap, -S sets the free swap minimum to SIZE KiB.
       The value is internally converted to a percentage.  If you pass both -S and -s, the lower value is used.

       Send SIGKILL if at or below KILL_SIZE (default SIZE/2), otherwise SIGTERM.

   -k
       removed in earlyoom v1.2, ignored for compatibility

   -i
       user-space oom killer should ignore positive oom_score_adj values

   -d
       enable debugging messages

   -v
       print version information and exit

   -r INTERVAL
       Time between printing periodic memory reports, in seconds (default 1.0).   A  memory  report  looks  like
       this:

              mem avail: 21790 of 23909 MiB (91.14%), swap free:    0 of    0 MiB ( 0.00%)

       Set to 3600 to print a report every hour, to 86400 to print once a day etc.  Set to 0 to disable printing
       periodic memory reports.  Free memory monitoring and low-memory killing runs independently of this option
       at  an adaptive poll rate that only depends on free memory.  Due to the adaptive poll rate, when there is
       a lot of free memory, the actual interval may be up to 1 second longer than the setting.

   -p
       Increase earlyoom’s priority: set niceness of earlyoom to -20 and oom_score_adj to -100.

       When earlyoom is run through its default systemd service, the -p switch doesn’t  work.   To  achieve  the
       same effect, enter the following three lines into sudo systemctl edit earlyoom:

              [Service]
              OOMScoreAdjust=-100
              Nice=-20

   -n
       Enable notifications via d-bus.

   --prefer REGEX
       prefer killing processes matching REGEX (adds 300 to oom_score)

   --avoid REGEX
       avoid killing processes matching REGEX (subtracts 300 from oom_score)

   --dryrun
       dry run (do not kill any processes)

   -h, --help
       this help text

EXIT STATUS

       0: Successful program execution.

       1: Other error - inspect message for details

       2: Switch conflict.

       4: Could not cd to /proc

       5: Could not open proc

       7: Could not open /proc/sysrq-trigger

       13: Unknown options.

       14: Wrong parameters for other options.

       15: Wrong parameters for memory threshold.

       16: Wrong parameters for swap threshold.

       102: Could not open /proc/meminfo

       103: Could not read /proc/meminfo

       104: Could not find a specific entry in /proc/meminfo

       105: Could not convert number when parse the contents of /proc/meminfo

Why not trigger the kernel oom killer?

       Earlyoom does not use echo f > /proc/sysrq-trigger because the Chrome people made their browser always be
       the  first  (innocent!) victim by setting oom_score_adj very high.  Instead, earlyoom finds out itself by
       reading through /proc/*/status (actually /proc/*/statm, which contains the same information but is easier
       to parse programmatically).

       Additionally, in recent kernels (tested on 4.0.5), triggering the kernel oom killer manually may not work
       at all.  That is, it may only free some graphics memory (that will be allocated  immediately  again)  and
       not actually kill any process.

MEMORY USAGE

       About 2 MiB VmRSS.  All memory is locked using mlockall() to make sure earlyoom does not slow down in low
       memory situations.

BUGS

       If  there is zero total swap on earlyoom startup, any -S (uppercase “S”) values are ignored, a warning is
       printed, and default swap percentages are used.

       For processes matched by --prefer, negative oom_score_adj values are not  taken  into  account,  and  the
       process  gets an effective oom_score of at least 300.  See https://github.com/rfjakob/earlyoom/issues/159
       for details.

AUTHOR

       The author of earlyoom is Jakob Unterwurzacher ⟨jakobunt@gmail.com⟩.

       This manual page was written by Yangfl ⟨mmyangfl@gmail.com⟩, for the Debian project (and may be  used  by
       others).

                                                                                                     earlyoom(1)