
This is a small daemon/libary to enable games to request a performance "game mode" from the system. Currently only implemented to upgrade the CPU governor and automatically downgrade it once done. A game only needs to load libgamemodeauto to activate the request. Which means an LD_PRELOAD can be applied to any game to activate the mode as needed. However gamemode_client.h can be used to manually activate/deactivate the mode as needed, and also perform error checking. The libs are miminal loaders to call into an installed libgamemode which, if the daemon is installed and running, will send through the equivelant game mode request, and magic will happen. See the README.md for more details. Currently licensed under the BSD 3 clause license.
GameMode
A preliminary implementation of a daemon/lib combo to allow games to request a performance mode from the host OS on Linux. It was designed primarily as a stop-gap solution to problems with the Intel and AMD CPU powersave or ondemand governors, but is intended to be expanded beyond just CPU power states as needed.
Currently using sd-bus
on the user bus internally for messaging
Components
Host
gamemoded
Runs in the background, waits for requests, refcounts and also checks caller PID lifetime.
Accepts -d
(daemonize) and -l
(log to syslog)
libgamemode
Dynamic library to dispatch requests to the daemon
Note: Behaviour of gamemoded
may change, so libgamemode
should never be linked with directly.
cpugovctl
Small program used to to control the cpu governor.
Accepts get
(gets current governor) and set <GOVERNOR>
(sets the current governor).
Clients
libgamemodeauto
Simple dynamic library that automatically requests game mode when loaded. Minimal dependencies.
Useful to LD_PRELOAD
into any game as needed.
gamemode_client.h
Very small header only lib that lets a game request game mode and handle errors. Minimal dependencies.
Can also be included with GAMEMODE_AUTO
defined to behave automatically.
Build and install
Daemon and host library
Dependencies
- meson
- systemd
# Ubuntu
apt install meson libsystemd-dev
# Arch
pacman -S meson systemd
git clone <git repo>
cd gamemode
meson --prefix=/usr build
cd build
ninja
sudo ninja install
Using with any game or program
After installing libgamemodeauto.so
simple preload it into the program. Examples:
LD_PRELOAD=/usr/lib/libgamemodeauto.so ./game
Or steam launch options
LD_PRELOAD=/usr/lib/libgamemodeauto.so %command%
Building into a game or program
You may want to build in functionality directly into an app, this stops the need for users to have to manually set anything up.
gamemode_client.h
and libgamemodeauto
are safe to use regardless of whether libgamemode and gamemoded are installed on the system. They also do not require systemd
.
Using directly
#include "gamemode_client.h"
if( gamemode_request_start() < 0 )
fprintf( stderr, "gamemode request failed: %s\n", gamemode_error_string() );
/* run game... */
gamemode_request_end(); // Not required, gamemoded will clean up after game exists anyway
Using automatically
Option 1: Include in code
#define GAMEMODE_AUTO
#include "gamemode_client.h"
Option 2: Link and distribute
Add -lgamemodeauto
to linker arguments and distribute libgamemodeauto.so
with the game
Option 3: Distribute and script
Distribute libgamemodeauto.so
with the game and add to LD_PRELOAD in a launch script
TODO
- Use polkit for cpugovctl (currently simply using chmod +4555)
- Implement some kind of user confuguration to allow for whitelists, extra behaviour, etc.