4 ms·

The thing I dislike about Wayland is: Sometimes the server will crash. Video drivers or something. Hasn't happened much with 22.04, but used to happen more fre

by Shorel 4y ago

The thing I dislike about Wayland is: Sometimes the server will crash. Video drivers or something. Hasn't happened much with 22.04, but used to happen more frequently before. Both with Intel and AMD. When this happens in X11, the server restarts, I see the screen go black for an instant, that's it. When this happens in Wayland, all my open programs are killed. No save prompts or anything, just insta-killed. This makes Wayland unusable unless they can guarantee no crashes, ever.

foxhill 4y ago
i really want to support Wayland. X has done us well, but it's about time a protocol based around more modern situations supplants it. Wayland has a myriad of these sharp-edge cases which i also find each time i try it out. what worries me a little is that some of them are clearly design decisions with no simple remidiation, your crashing example (which i have also witnessed first hand) is one of them.
thrwawy74 4y ago
I think currently we have compositors that are monolithic and due "it all". Sounds like we'd need a separate process to maintain window state, that the compositor interfaces with. is this recreating some of the problems of X11?
- account42 4y ago
  Perhaps a better approach would be to make sure that clients can wait for the server to restart and reconnect. Then you don't need any crash-proof server part.
rhn_mk1 4y ago
To be nitpicky, if the X server crashes, you're just as hosed with X as with Wayland. The difference is that X survives a window manager crash, whereas Wayland typically does not, because on Wayland it's usually the same process as the server.
shmerl 4y ago
If you have a GPU hang and reset, X11 isn't going to be any better. There is some WIP to make recovery from GPU hangs more robust. It's not there yet. * https://www.youtube.com/watch?v=fRdnRwPBFBk https://www.youtube.com/watch?v=fRdnRwPBFBk * https://invent.kde.org/plasma/kwin/-/wikis/Restarting https://invent.kde.org/plasma/kwin/-/wikis/Restarting Though I'm not sure what's the current status of that is or how actively it's progressing. Hopefully it will turn into something usable, it's important.
- delusional 4y ago
  I takkede to an X11 dev once about this. I remember him saying that X supports recovering already. The issues was that most compositors and applications did not.
  - shmerl 4y ago
    In practice you can't recover and need a reboot even if in theory it's possible.
    - account42 4y ago
      GPU recovery did use to work on radeonsi with compositing disabled at some point. Of course you are usually better off rebooting anyways because who knows what state all the million bits of the GPU were left in after a crash that is by definition an unanticipated event.
arghwhat 4y ago
A display server crash is fatal under X. A window manager crash is not. A window manager is not particularly affected by GPU drivers. What you see might be a GPU hang or reset that recovered. Some Wayland compositors have a window manager model by using an external process for window positioning logic (e.g. river). This is mostly just for convenience of development though, making it easy to experiment with layout engines.
- account42 4y ago
  > A window manager is not particularly affected by GPU drivers. Since the window manager is also the compositor in many X setups (e.g. GNOME and KDE), the WM is very much affected by GPU drivers. It doesn't have to be the GPU drivers though, plenty of complexity in the WM/compositor itself. The core complaint is absolutely valid - the protocol and libraries should have been designed so that applications can recover from a server crash/restart, even if the legacy X server does not provide that guarantee.
brnt 4y ago
Same here. Only, Wayland just hangs the entire screen, no recovery possible. I could reproduce this across distros and hardware (Intel, AMD and Nvidia). This was using stock Fedora 34, and I haven't tried since, because those hangs would occur within minutes of boot and I the closest I could come was "must be a driver bug". Exactly the same bug for all three GPU makers... Unfortunately, nobody seems interested in such user reports or quality control (apparently, turns out there are many like us who're getting "upgrade your hardware", "works for me", "user error", etc. I retreated to Debian stable, which is indeed very stable.
- txtsd 4y ago
  I experience the hangs every time my partner switches to a new TTY to use their profile and I switch back to try to access mine.
LtWorf 4y ago
> When this happens in X11, the server restarts, I see the screen go black for an instant, that's it. Your windows manager crashed. If xorg had crashed you'd have lost your data.

by Shorel 4y ago

foxhill 4y ago

i really want to support Wayland. X has done us well, but it's about time a protocol based around more modern situations supplants it. Wayland has a myriad of these sharp-edge cases which i also find each time i try it out. what worries me a little is that some of them are clearly design decisions with no simple remidiation, your crashing example (which i have also witnessed first hand) is one of them.

thrwawy74 4y ago

I think currently we have compositors that are monolithic and due "it all". Sounds like we'd need a separate process to maintain window state, that the compositor interfaces with. is this recreating some of the problems of X11?

account42 4y ago
Perhaps a better approach would be to make sure that clients can wait for the server to restart and reconnect. Then you don't need any crash-proof server part.

rhn_mk1 4y ago

To be nitpicky, if the X server crashes, you're just as hosed with X as with Wayland. The difference is that X survives a window manager crash, whereas Wayland typically does not, because on Wayland it's usually the same process as the server.

shmerl 4y ago

If you have a GPU hang and reset, X11 isn't going to be any better. There is some WIP to make recovery from GPU hangs more robust. It's not there yet. * https://www.youtube.com/watch?v=fRdnRwPBFBk https://www.youtube.com/watch?v=fRdnRwPBFBk * https://invent.kde.org/plasma/kwin/-/wikis/Restarting https://invent.kde.org/plasma/kwin/-/wikis/Restarting Though I'm not sure what's the current status of that is or how actively it's progressing. Hopefully it will turn into something usable, it's important.

delusional 4y ago
I takkede to an X11 dev once about this. I remember him saying that X supports recovering already. The issues was that most compositors and applications did not.
- shmerl 4y ago
  In practice you can't recover and need a reboot even if in theory it's possible.
  - account42 4y ago
    GPU recovery did use to work on radeonsi with compositing disabled at some point. Of course you are usually better off rebooting anyways because who knows what state all the million bits of the GPU were left in after a crash that is by definition an unanticipated event.

arghwhat 4y ago

A display server crash is fatal under X. A window manager crash is not. A window manager is not particularly affected by GPU drivers. What you see might be a GPU hang or reset that recovered. Some Wayland compositors have a window manager model by using an external process for window positioning logic (e.g. river). This is mostly just for convenience of development though, making it easy to experiment with layout engines.

account42 4y ago
> A window manager is not particularly affected by GPU drivers. Since the window manager is also the compositor in many X setups (e.g. GNOME and KDE), the WM is very much affected by GPU drivers. It doesn't have to be the GPU drivers though, plenty of complexity in the WM/compositor itself. The core complaint is absolutely valid - the protocol and libraries should have been designed so that applications can recover from a server crash/restart, even if the legacy X server does not provide that guarantee.

brnt 4y ago

Same here. Only, Wayland just hangs the entire screen, no recovery possible. I could reproduce this across distros and hardware (Intel, AMD and Nvidia). This was using stock Fedora 34, and I haven't tried since, because those hangs would occur within minutes of boot and I the closest I could come was "must be a driver bug". Exactly the same bug for all three GPU makers... Unfortunately, nobody seems interested in such user reports or quality control (apparently, turns out there are many like us who're getting "upgrade your hardware", "works for me", "user error", etc. I retreated to Debian stable, which is indeed very stable.

txtsd 4y ago
I experience the hangs every time my partner switches to a new TTY to use their profile and I switch back to try to access mine.

LtWorf 4y ago

> When this happens in X11, the server restarts, I see the screen go black for an instant, that's it. Your windows manager crashed. If xorg had crashed you'd have lost your data.