gerrit.sh - OOM score adjustment (suggestion)

[Lorenzo Buzzi]

Hello everybody,
I have been using Gerrit since version 3.8 (I am currently on 3.12) on a Linux server and manage it with systemd using the unit file from https://github.com/eloy83/gerrit-systemd/.

I noticed that at startup, the gerrit.sh script prints this output:
WARNING: Could not adjust Gerrit's process for the kernel's out-of-memory killer.
         This may be caused by <gerrit's path>/bin/gerrit.sh not being run as root.
         Consider changing the OOM score adjustment manually for Gerrit's PID=XXXXXX with e.g.:
         echo “-1000” | sudo tee /proc/XXXXXX/oom_score_adj

systemd allows you to set oom_score_adj with a simple directive in the unit file:
[Service]
...
OOMScoreAdjust=-1000

The problem, in my case, is that gerrit.sh is not run as root and the setting made by systemd, although effective, does not suppress the warning.  I also took a look at the unit file included in the official gerrit tree (resources/com/google/gerrit/pgm/init/gerrit.service), but that also starts the service as the gerritsrv user and therefore displays the same warning.

I suggest a small change to gerrit.sh that solves this problem. The lines I added are in red:

    PID=`cat "$GERRIT_PID"`
    if test $UID = 0; then
        if test -f "/proc/${PID}/oom_score_adj" ; then
            echo -1000 > "/proc/${PID}/oom_score_adj"
        else
            if test -f "/proc/${PID}/oom_adj" ; then
                echo -16 > "/proc/${PID}/oom_adj"
            fi
        fi
    elif test -f "/proc/${PID}/oom_score_adj" && [ "$(cat "/proc/${PID}/oom_score_adj")"=="-1000" ]; then
        :
    elif test -f "/proc/${PID}/oom_adj" && [ "$(cat "/proc/${PID}/oom_adj")"=="-16" ]; then
        :
    elif [ "$(uname -s)"=="Linux" ] && test -d "/proc/${PID}"; then
        echo "WARNING: Could not adjust Gerrit's process for the kernel's out-of-memory killer."
        echo "         This may be caused by ${0} not being run as root."
        echo "         Consider changing the OOM score adjustment manually for Gerrit's PID=${PID} with e.g.:"
        echo "         echo '-1000' | sudo tee /proc/${PID}/oom_score_adj"
    fi

If you think it might be useful, feel free to integrate them into the official code or use them as inspiration for something even better.

Regards,

Lorenzo Buzzi

[Lorenzo Buzzi]

I found a small error in my lines and also in one of the original lines of the script.

[ "${VARIABLE}"=="value" ] in POSIX returns always true.

The correct syntax is [ "${VARIABLE}" = "value" ].

The fixes are in-line red below.

Alternatives in blue.

Il giorno venerdì 27 febbraio 2026 alle 13:34:08 UTC+1 Lorenzo Buzzi ha scritto:

Hello everybody,
I have been using Gerrit since version 3.8 (I am currently on 3.12) on a Linux server and manage it with systemd using the unit file from https://github.com/eloy83/gerrit-systemd/.

I noticed that at startup, the gerrit.sh script prints this output:
WARNING: Could not adjust Gerrit's process for the kernel's out-of-memory killer.
         This may be caused by <gerrit's path>/bin/gerrit.sh not being run as root.
         Consider changing the OOM score adjustment manually for Gerrit's PID=XXXXXX with e.g.:
         echo “-1000” | sudo tee /proc/XXXXXX/oom_score_adj

systemd allows you to set oom_score_adj with a simple directive in the unit file:
[Service]
...
OOMScoreAdjust=-1000

The problem, in my case, is that gerrit.sh is not run as root and the setting made by systemd, although effective, does not suppress the warning.  I also took a look at the unit file included in the official gerrit tree (resources/com/google/gerrit/pgm/init/gerrit.service), but that also starts the service as the gerritsrv user and therefore displays the same warning.

I suggest a small change to gerrit.sh that solves this problem. The lines I added are in red:

    PID=`cat "$GERRIT_PID"`
    if test $UID = 0; then
        if test -f "/proc/${PID}/oom_score_adj" ; then
            echo -1000 > "/proc/${PID}/oom_score_adj"
        else
            if test -f "/proc/${PID}/oom_adj" ; then
                echo -16 > "/proc/${PID}/oom_adj"
            fi
        fi
    elif test -f "/proc/${PID}/oom_score_adj" && [ "$(cat "/proc/${PID}/oom_score_adj")"=="-1000" ]; then

elif test -f "/proc/${PID}/oom_score_adj" && [ "$(cat "/proc/${PID}/oom_score_adj")" = "-1000" ]; then

or

elif test -f "/proc/${PID}/oom_score_adj" && ! [ "$(cat "/proc/${PID}/oom_score_adj")" = "0" ]; then

        :
    elif test -f "/proc/${PID}/oom_adj" && [ "$(cat "/proc/${PID}/oom_adj")"=="-16" ]; then

elif test -f "/proc/${PID}/oom_adj" && [ "$(cat "/proc/${PID}/oom_adj")" = "-16" ]; then

or

elif test -f "/proc/${PID}/oom_adj" && ! [ "$(cat "/proc/${PID}/oom_adj")" = "0" ]; then

        :
    elif [ "$(uname -s)"=="Linux" ] && test -d "/proc/${PID}"; then

elif [ "$(uname -s)" = "Linux" ] && test -d "/proc/${PID}"; then

[mfick]

Unfortunately, we cannot accept email contributions as the gerrit CLA must be signed first. Could you upload these as changes to the Gerrit project?

Thanks,

-Martin

[Daniele Sassoli]

On Friday, 27 February 2026 at 16:20:14 UTC mfick wrote:

Unfortunately, we cannot accept email contributions as the gerrit CLA must be signed first. Could you upload these as changes to the Gerrit project?

For posterity, Lorenzo raised a change at [1].

[1] https://gerrit-review.googlesource.com/c/gerrit/+/556861