4 ms·

Wayland developers specifically prioritize the "every frame is perfect" paradigm over performance and latency. This means there will never be an option to disab

by sprash 7y ago

Wayland developers specifically prioritize the "every frame is perfect" paradigm over performance and latency. This means there will never be an option to disable things like composition or vsync. Also, even though it is always claimed that "X11 a is messy conglomerate of tacked on technologies and extensions" the Wayland protocol is extremely complex despite severely lacking features. And because of the strange priorities it has worse performance than X11 even for native apps. The self proclaimed "minimalist" wlroots library has more than 50000 LOC, all for moving around a bunch of overlapping windows? A bit much.

ddevault 7y ago
The Wayland protocol is actually very simple, much simpler than X. And consider that wlroots+sway is around 100,000 LOC, but it's at least as capable as i3+xorg - which is a million lines of code.
- ubercow13 7y ago
  Really claiming that it's at least as capable as xorg seems like a complete misrepresentation. Aren't some of the most common and enduring complaints about Wayland about missing features compared to X?
  - ddevault 7y ago
    Uninformed and mostly outdated complaints, generally. What features are left unturned are in progress and have most of the pieces in place, and their realization will not add enough lines of code to come close to Xorg.
floatboth 7y ago
> extremely complex Really? I can run any app with WAYLAND_DEBUG=1 and understand every message easily. > because of the strange priorities it has worse performance than X11 If the performance that matters to you is the tiny bit of latency caused by vsync, keep using Xorg, or Windows 95, or whatever. Wayland is inherently much faster because it's asynchronous and doesn't have anything in between the compositor and the clients (e.g.: app <-> Xorg <-> Compiz — xorg is just a glorified message broker!). > wlroots library has more than 50000 LOC, all for moving around a bunch of overlapping windows? A bit much Minus 8.5k for examples, minus 7k for the big example (rootston). It's not just moving windows around. Input is inherently complex, and it supports touchscreens, touchpad gestures, drawing tablets, virtual keyboards, pointer locking (moving the camera with the mouse in first person videogames).. Also, it implements multiple backends — running on KMS/DRM, nested on Wayland and X11, and as an RDP server. Considering that it's all in C, that's a tiny number of lines. More importantly than silly metrics, it's a modern, easy to get into codebase. How much does Xorg have, with its five or however many input systems, multiple legacy ways of direct rendering, and whatever other crap it's accumulated?
bscphil 7y ago
> Wayland developers specifically prioritize the "every frame is perfect" paradigm over performance and latency. This means there will never be an option to disable things like composition or vsync. Sorry if I'm misunderstanding, but isn't this terrible? Won't it mean that video games are going to be completely unplayable on Wayland desktops? I've never been able to get acceptable performance in a game on Wayland, but I'd always assumed that this was just because it was a work in progress and the game makers didn't test to ensure proper performance on anything but X.
- sprash 7y ago
  X11 applications are able to directly render pixels on the screen via OpenGL. In Wayland those pixels are always rendered to a buffer which will then be composed on the screen. This doesn't mean games will be "unplayable". It just means that the performance will depend on the compositor. And since the compositor also includes functionality originally provided by window managers you might get into a situation where you can't use you tiling or whatever desktop for gaming and have to switch compositors for different applications with different priorities. Fun times...
  - Crinus 7y ago
    Note that Wayland introduces latency between input (you doing something) and output (seeing the result of your action), see my other posts for detail. While this latency wont make a game unplayable, it will make the experience worse for fast paced games (especially games where you control the camera directly with the mouse). However this is an issue if you are running a game in a window, the compositor should get out of the way when running fullscreen (or at least i hope it does, but that is the same with X11, some compositors see a fullscreen window and consider it perfectly fine to keep going on).
    - chousuke 7y ago
      Do you actually have benchmarks and evidence showing that Wayland introduces latency over X11, or is it just a guess based on how you think Wayland works? I mean, sure it might in some cases where you can use X11 to "directly" draw stuff on the screen, but most games would be double-buffering or triple-buffering anyway. I don't really see why Wayland would add any latency there, considering all the compositing is going to happen on the GPU anyway.
ilikehurdles 7y ago
> there will never be an option to disable things like composition or vsync Wait, is there a coupling between composition and vsync? I do enjoy playing games on linux, and forcing vsync enabled is an absolute non starter for me.
- nwallin 7y ago
  There is no hard dependency between composition and vsync. You can disable composition with vsync enabled, or you can have composition with novsync. (in practice they tend to be highly correlated) However, Wayland supports neither disabling vsync nor disabling composition. Moreover, it was architected this way; there's not really any hope of disabling the compositor. Freesync looks kinda sorta like vsync if you squint at it right, so maybe there's hope for freesync in the distant future. But right now, Wayland does not support freesync, nor are there plans to implement it. Gaming on Wayland is 'lol nope' at this point, and will remain that way for the forseeable future. This news is deeply troubling.
tadfisher 7y ago
> The self proclaimed "minimalist" wlroots library has more than 50000 LOC, all for moving around a bunch of overlapping windows? wlroots is most of a display compositor implementation, so you should be comparing it to all of the X libraries used in a compositor, and of course the server itself. I suspect the combination would easily exceed 1 million lines.

by sprash 7y ago

ddevault 7y ago

The Wayland protocol is actually very simple, much simpler than X. And consider that wlroots+sway is around 100,000 LOC, but it's at least as capable as i3+xorg - which is a million lines of code.

ubercow13 7y ago
Really claiming that it's at least as capable as xorg seems like a complete misrepresentation. Aren't some of the most common and enduring complaints about Wayland about missing features compared to X?
- ddevault 7y ago
  Uninformed and mostly outdated complaints, generally. What features are left unturned are in progress and have most of the pieces in place, and their realization will not add enough lines of code to come close to Xorg.

floatboth 7y ago

> extremely complex Really? I can run any app with WAYLAND_DEBUG=1 and understand every message easily. > because of the strange priorities it has worse performance than X11 If the performance that matters to you is the tiny bit of latency caused by vsync, keep using Xorg, or Windows 95, or whatever. Wayland is inherently much faster because it's asynchronous and doesn't have anything in between the compositor and the clients (e.g.: app <-> Xorg <-> Compiz — xorg is just a glorified message broker!). > wlroots library has more than 50000 LOC, all for moving around a bunch of overlapping windows? A bit much Minus 8.5k for examples, minus 7k for the big example (rootston). It's not just moving windows around. Input is inherently complex, and it supports touchscreens, touchpad gestures, drawing tablets, virtual keyboards, pointer locking (moving the camera with the mouse in first person videogames).. Also, it implements multiple backends — running on KMS/DRM, nested on Wayland and X11, and as an RDP server. Considering that it's all in C, that's a tiny number of lines. More importantly than silly metrics, it's a modern, easy to get into codebase. How much does Xorg have, with its five or however many input systems, multiple legacy ways of direct rendering, and whatever other crap it's accumulated?

bscphil 7y ago

> Wayland developers specifically prioritize the "every frame is perfect" paradigm over performance and latency. This means there will never be an option to disable things like composition or vsync. Sorry if I'm misunderstanding, but isn't this terrible? Won't it mean that video games are going to be completely unplayable on Wayland desktops? I've never been able to get acceptable performance in a game on Wayland, but I'd always assumed that this was just because it was a work in progress and the game makers didn't test to ensure proper performance on anything but X.

sprash 7y ago
X11 applications are able to directly render pixels on the screen via OpenGL. In Wayland those pixels are always rendered to a buffer which will then be composed on the screen. This doesn't mean games will be "unplayable". It just means that the performance will depend on the compositor. And since the compositor also includes functionality originally provided by window managers you might get into a situation where you can't use you tiling or whatever desktop for gaming and have to switch compositors for different applications with different priorities. Fun times...
- Crinus 7y ago
  Note that Wayland introduces latency between input (you doing something) and output (seeing the result of your action), see my other posts for detail. While this latency wont make a game unplayable, it will make the experience worse for fast paced games (especially games where you control the camera directly with the mouse). However this is an issue if you are running a game in a window, the compositor should get out of the way when running fullscreen (or at least i hope it does, but that is the same with X11, some compositors see a fullscreen window and consider it perfectly fine to keep going on).
  - chousuke 7y ago
    Do you actually have benchmarks and evidence showing that Wayland introduces latency over X11, or is it just a guess based on how you think Wayland works? I mean, sure it might in some cases where you can use X11 to "directly" draw stuff on the screen, but most games would be double-buffering or triple-buffering anyway. I don't really see why Wayland would add any latency there, considering all the compositing is going to happen on the GPU anyway.

ilikehurdles 7y ago

> there will never be an option to disable things like composition or vsync Wait, is there a coupling between composition and vsync? I do enjoy playing games on linux, and forcing vsync enabled is an absolute non starter for me.

nwallin 7y ago
There is no hard dependency between composition and vsync. You can disable composition with vsync enabled, or you can have composition with novsync. (in practice they tend to be highly correlated) However, Wayland supports neither disabling vsync nor disabling composition. Moreover, it was architected this way; there's not really any hope of disabling the compositor. Freesync looks kinda sorta like vsync if you squint at it right, so maybe there's hope for freesync in the distant future. But right now, Wayland does not support freesync, nor are there plans to implement it. Gaming on Wayland is 'lol nope' at this point, and will remain that way for the forseeable future. This news is deeply troubling.

tadfisher 7y ago

> The self proclaimed "minimalist" wlroots library has more than 50000 LOC, all for moving around a bunch of overlapping windows? wlroots is most of a display compositor implementation, so you should be comparing it to all of the X libraries used in a compositor, and of course the server itself. I suspect the combination would easily exceed 1 million lines.