USER@.SERVICE(5) user@.service USER@.SERVICE(5) user@.service, user-runtime-dir@.service, systemd-user-runtime-dir - user@UID.service user-runtime-dir@UID.service /usr/lib/systemd/systemd-user-runtime-dir user-UID.slice systemd(1) (PID 1) user@UID.service (UID) . . systemd --user . systemd(1) systemd.special(7) . user@UID.service user-runtime-dir@UID.service /run/user/UID . /tmp/ / /dev/shm/ . user-runtime-dir@UID.service systemd-user-runtime-dir . user@.service . sshd(8) gdm .scope ( systemd.scope(5)). user@UID.service user-UID.slice. user-UID.slice user.slice systemd.special(7). . user.slice . /etc/systemd/system/user.slice.d/resources.conf. user-UID.slice. /etc/systemd/system/user-1000.slice.d/resources.conf. user-.slice. /etc/systemd/system/user-.slice.d/resources.conf user-UID.slice systemd.unit(5) . .scope ( ) pam_systemd(8). PAM systemd-logind(8) . PAM pam_systemd(8). . user@UID.service systemd.resource-control(5) . 1. $ systemd-cgls Control group /: -.slice user.slice | user-1000.slice | | user@1000.service | | | pulseaudio.service | | | | 2386 /usr/bin/pulseaudio --daemonize=no | | | gnome-terminal-server.service | | | init.scope | | | 4127 /usr/libexec/gnome-terminal-server | | | 4198 zsh | | ... | | session-4.scope | | 1264 gdm-session-worker [pam/gdm-password] | | 2339 /usr/bin/gnome-shell | | ... | | session-19.scope | | 6497 sshd: zbyszek [priv] | | 6502 sshd: zbyszek@pts/6 | | 6509 -zsh | | 6602 systemd-cgls --no-pager | ... | user-1001.slice | session-20.scope | | 6675 sshd: guest [priv] | | 6708 sshd: guest@pts/6 | | 6717 -bash | user@1001.service | init.scope | | 6680 /usr/lib/systemd/systemd --user | | 6688 (sd-pam) | sleep.service | 6706 /usr/bin/sleep 30 ... UID 1000 gdm (session-4.scope) ssh(1) (session-19.scope) (user@1000.service). UID 1001 ssh (session-20.scope) (user@1001.service). () user-1000.slice user-1001.slice user.slice. user@.service (pulseaudio.service, gnome-terminal-server.service, init.scope, sleep.service). 2. $ systemctl cat user-1000.slice # /usr/lib/systemd/system/user-.slice.d/10-defaults.conf # ... [Unit] Description=User Slice of UID %j After=systemd-user-sessions.service [Slice] TasksMax=33% user-UID.slice . . systemd(1), systemd.service(5), systemd.slice(5), systemd.resource-control(5), systemd.exec(5), systemd.special(7), capsule@.service(5), pam(8) 3 . . : . systemd 260.2 USER@.SERVICE(5)