Everyone wants the Linux distribution they are using to be fast. This is practically a content-free statement, of course: who would want their distro to be slow? But at the same time, what does it mean for your distribution to be fast? For example, Ubuntu 21.10 switched the default compression for packages to zstd, which […]
I only know of real-time kernels, which allow to measure/calculate the maximum response time of an application. This is important for critical processes, like braking in your car, but decreases performance slightly rather than increase responsiveness.
I mean real-time scheduler, not real-time kernel. Found an article that says kwin_wayland uses SCHED_FIFO.
man 7 sched says:
SCHED_FIFO can be used only with static priorities higher than 0, which means that when a SCHED_FIFO thread becomes runnable, it will always immediately preempt any currently running SCHED_OTHER, SCHED_BATCH, or SCHED_IDLE thread.
but decreases performance slightly rather than increase responsiveness.
Responsiveness is not performance. There are 3 main performance metrics: throughput, latency and jitter. Responsiveness is mostly latency, but sometimes jitter. You can for example run game in 30fps with 0.01s lag or in 60 fps with 1s lag. In second case FPS is higher, but, player will feel game unresponsive because of time it takes between pressing button and game showing the result.
What do you mean with real-time mode?
I only know of real-time kernels, which allow to measure/calculate the maximum response time of an application. This is important for critical processes, like braking in your car, but decreases performance slightly rather than increase responsiveness.
I mean real-time scheduler, not real-time kernel. Found an article that says kwin_wayland uses SCHED_FIFO.
man 7 schedsays:Responsiveness is not performance. There are 3 main performance metrics: throughput, latency and jitter. Responsiveness is mostly latency, but sometimes jitter. You can for example run game in 30fps with 0.01s lag or in 60 fps with 1s lag. In second case FPS is higher, but, player will feel game unresponsive because of time it takes between pressing button and game showing the result.
Thanks for the link, real-time mode definitely makes sense and should be implemented for all compositors imo.
True, I miswrote. What I wanted to write was