限制单个Linux进程的内存使用

#1 楼

#2 楼

cgcreate -g memory:myGroup
echo 500M > /sys/fs/cgroup/memory/myGroup/memory.limit_in_bytes
echo 5G > /sys/fs/cgroup/memory/myGroup/memory.memsw.limit_in_bytes

cgexec -g memory:myGroup pdftoppm

GRUB_CMDLINE_LINUX_DEFAULT="cgroup_enable=memory swapaccount=1"

#3 楼

#4 楼

 systemd-run --scope -p MemoryMax=500M pdftoppm
 

#5 楼

GRUB_CMDLINE_LINUX="swapaccount=1"

 #!/bin/sh

# This script uses commands from the cgroup-tools package. The cgroup-tools commands access the cgroup filesystem directly which is against the (new-ish) kernel's requirement that cgroups are managed by a single entity (which usually will be systemd). Additionally there is a v2 cgroup api in development which will probably replace the existing api at some point. So expect this script to break in the future. The correct way forward would be to use systemd's apis to create the cgroups, but afaik systemd currently (feb 2018) only exposes dbus apis for which there are no command line tools yet, and I didn't feel like writing those.

# strict mode: error if commands fail or if unset variables are used
set -eu

if [ "$#" -lt 2 ]
then
    echo Usage: `basename q4312079q` "<limit> <command>..."
    echo or: `basename q4312079q` "<memlimit> -s <swaplimit> <command>..."
    exit 1
fi

cgname="limitmem_$$"

# parse command line args and find limits

limit=""
swaplimit="$limit"
shift

if [ "" = "-s" ]
then
    shift
    swaplimit=""
    shift
fi

if [ "" = -- ]
then
    shift
fi

if [ "$limit" = "$swaplimit" ]
then
    memsw=0
    echo "limiting memory to $limit (cgroup $cgname) for command $@" >&2
else
    memsw=1
    echo "limiting memory to $limit and total virtual memory to $swaplimit (cgroup $cgname) for command $@" >&2
fi

# create cgroup
sudo cgcreate -g "memory:$cgname"
sudo cgset -r memory.limit_in_bytes="$limit" "$cgname"
bytes_limit=`cgget -g "memory:$cgname" | grep memory.limit_in_bytes | cut -d\  -f2`

# try also limiting swap usage, but this fails if the system has no swap
if sudo cgset -r memory.memsw.limit_in_bytes="$swaplimit" "$cgname"
then
    bytes_swap_limit=`cgget -g "memory:$cgname" | grep memory.memsw.limit_in_bytes | cut -d\  -f2`
else
    echo "failed to limit swap"
    memsw=0
fi

# create a waiting sudo'd process that will delete the cgroup once we're done. This prevents the user needing to enter their password to sudo again after the main command exists, which may take longer than sudo's timeout.
tmpdir=${XDG_RUNTIME_DIR:-$TMPDIR}
tmpdir=${tmpdir:-/tmp}
fifo="$tmpdir/limitmem_$$_cgroup_closer"
mkfifo --mode=u=rw,go= "$fifo"
sudo -b sh -c "head -c1 '$fifo' >/dev/null ; cgdelete -g 'memory:$cgname'"

# spawn subshell to run in the cgroup. If the command fails we still want to remove the cgroup so unset '-e'.
set +e
(
set -e
# move subshell into cgroup
sudo cgclassify -g "memory:$cgname" --sticky `sh -c 'echo $PPID'`  # $$ returns the main shell's pid, not this subshell's.
exec "$@"
)

# grab exit code 
exitcode=$?

set -e

# show memory usage summary

peak_mem=`cgget -g "memory:$cgname" | grep memory.max_usage_in_bytes | cut -d\  -f2`
failcount=`cgget -g "memory:$cgname" | grep memory.failcnt | cut -d\  -f2`
percent=`expr "$peak_mem" / \( "$bytes_limit" / 100 \)`

echo "peak memory used: $peak_mem ($percent%); exceeded limit $failcount times" >&2

if [ "$memsw" = 1 ]
then
    peak_swap=`cgget -g "memory:$cgname" | grep memory.memsw.max_usage_in_bytes | cut -d\  -f2`
    swap_failcount=`cgget -g "memory:$cgname" |grep memory.memsw.failcnt | cut -d\  -f2`
    swap_percent=`expr "$peak_swap" / \( "$bytes_swap_limit" / 100 \)`

    echo "peak virtual memory used: $peak_swap ($swap_percent%); exceeded limit $swap_failcount times" >&2
fi

# remove cgroup by sending a byte through the pipe
echo 1 > "$fifo"
rm "$fifo"

exit $exitcode
 

#6 楼

#7 楼

# create cgroup
sudo cgcreate -g "memory:$cgname"
sudo cgset -r memory.limit_in_bytes="$limit" "$cgname"
sudo cgset -r memory.swappiness=0 "$cgname"
bytes_limit=`cgget -g "memory:$cgname" | grep memory.limit_in_bytes | cut -d\  -f2`

#8 楼