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 unresponsive 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 (highest 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 (default 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.  You can only use
       either -m or -M.

       Send 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.  You can only use  either
       -s or -S.

       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
       memory  report  interval  in  seconds  (default  1), set to 0 to disable completely.  With
       earlyoom v1.2 and higher, floating point numbers are accepted.  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 -1000

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

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

   -h, --help
       this help text

EXIT STATUS

       0: Successful program execution.

       1: Usage printed (using -h).

       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.

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)