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XWayland Aiming For Glamor Support, Merge Next X.Org Release

Posted by Unknown on from the almost-there dept.

An anonymous reader writes that XWayland is nearly ready to be merged into the main X.org tree "X.Org Server 1.16 this summer should support XWayland, the means of allowing X11 applications to run atop Wayland-based compositors without the need for any application/game changes. With the revised design, XWayland has generic 2D acceleration over OpenGL and a cleaner design compared to earlier revisions. With GNOME 3.12 having better Wayland support and Plasma Next around the corner, it looks like 2014 could be the year of Wayland's take-off!" The patch series emails have more details. The big news here is that XWayland is ditching its old DDX model for one based on Glamor. eliminating the need for any X.org drivers to be written to support X11 on Wayland: "Finally, the last patch adds the Xwayland DDX. Initially Xwayland was an Xorg module that exposed an API for Xorg video drivers to hook into so that we could reuse the native 2D acceleration. Now that glamor is credible and still improving, a much better approach is to make Xwayland its own DDX and use glamor for acceleration. A lot of the code in the Xorg approach was busy preventing Xorg being Xorg, eg, preventing VT access, preventing input driver loading, preventing drivers doing modesetting. The new DDX in contrast is straight-forward, clean code, only 2500 lines of code and neatly self-contained." It does not yet have direct rendering or any acceleration, but those patches should come soon.

21 of 83 comments (clear)

  1. HALLELUJAH! by krewemaynard · · Score: 4, Funny

    The Year of the Linux Desktop is upon us!

    --
    I saw it on Slashdot, it must be true!
    1. Re:HALLELUJAH! by H0p313ss · · Score: 3, Informative

      The Year of the Linux Desktop is upon us!

      Again?

      --
      XML is a known as a key material required to create SMD: Software of Mass Destruction
  2. Remote display across network? by dbc · · Score: 2

    OK, so I need to buy a clue here... does this move the ball forward with respect to being able to run an X-Windows client application on one node, and set the display back to a Wayland-based display server running on another node elsewhere on the network?

    1. Re:Remote display across network? by robmv · · Score: 4, Informative

      Yes, XWayland can be compared to an X Server running on Windows or over OS X, it translates X to the native display, in this case Wayland

    2. Re:Remote display across network? by sjames · · Score: 3, Insightful

      Actually, I do *NOT* want VNC. My objective is to run an X app on a server that itself has no video capabilities at all and have that window appear fully integrated on my workstation desktop. I do not want a window that contains an entirely unneeded desktop that contains the app window that I actually want.

      VNC does not work better for that application, at all.

    3. Re:Remote display across network? by washu_k · · Score: 3, Informative

      Neither VNC or RDP require that the server have any local video capabilities. It is quite possible to run a Windows server headless.

      RDP can remote single applications and has been able to for years. No full desktop required.

    4. Re:Remote display across network? by sjames · · Score: 2

      Vnc requires most of the things a full X server installation require and it's a bit clunky to use as a bonus. Compare to "ssh me@server -c MyXapp".

      What do you recommend for forwarding a single app from Linux server to Linus workstation?

    5. Re:Remote display across network? by TheRealMindChild · · Score: 3, Informative

      No one WANTS VNC. The very idea of POLLING for changes is pretty much the worst approach to a remote display that you can come up with.

      --

      "When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
  3. Re:How to you know Plasma Next will support Waylan by TheCycoONE · · Score: 2

    The actual article where he says Plasma Next will not (at least initially) support Wayland is: http://blog.martin-graesslin.c...

  4. Is XWayland... by unixisc · · Score: 2

    ... a part of X11 or a part of Wayland? Where exactly does it fit?

    1. Re:Is XWayland... by Shimbo · · Score: 4, Informative

      XWayland is the X server for Wayland, so that you can run traditional X applications on Wayland (as opposed to Qt etc. applications, which will talk directly to Wayland). http://wayland.freedesktop.org...

    2. Re:Is XWayland... by Kjella · · Score: 3, Informative

      Client X11 apps speak the X11 protocol to XWayland, XWayland speaks the Wayland protocol to Wayland so it's basically a big compatility shim. From Wayland's side it's just another client and if you use an X11 server you don't need it, it's not really part of either. Maybe the closest analogy is WINE, if you use Windows or run native Linux applications you don't need it. But if you want to run Windows applications on Linux you need WINE, likewise if you want to run X11 applications on Wayland you need XWayland. Basically you take an X11 server, stop it from talking to actual hardware and makes it draw to a Wayland window instead.

      --
      Live today, because you never know what tomorrow brings
  5. Is it just me? by benjfowler · · Score: 3, Insightful

    Is it just me, or is the Linux graphical stack insanely complex? Every time I read about it, they've introduced three new acronyms.

    1. Re:Is it just me? by neuro88 · · Score: 2, Insightful

      At this point, it's mostly just you. All this work going on vastly simplifies the stack. Wayland compositors are much simpler than the entire X stack (which has to be supported even though much of it isn't used). Unfortunately, X still needs to stay around in some capacity so we can still play our proprietary games ,etc.

  6. Re: acceleration by jgotts · · Score: 2

    Anything without acceleration is an experiment. It doesn't matter how many lines of code you've written, or how efficient it seems. 100% of the required functionality is acceleration.

    Acceleration is why X is being replaced by Wayland. 2D X11 requires a separate driver for every different type of hardware. 3D X11, from what I read by the Wayland people themselves, has three different APIs. For a long time, the only drivers with good 3D acceleration were proprietary drivers from AMD and nVidia.

    I want Wayland to succeed, but I feel that it's still a long way off. The devil is in the acceleration. Think about the time spent by XFree86 developers over the decades writing acceleration code versus everything else, and that's the part we're missing right now. I'm not very clear on just where the acceleration is missing, but it sounds like it's missing in a foundational piece.

  7. X from user space by FithisUX · · Score: 2

    With Wayland/Mir people should consider pushing X totally on user space, like Xming,VcXsrv,XDarwin (and XPhoton R.I.P.) with an SDL fallback.

    1. Re:X from user space by sjames · · Score: 4, Informative

      X has always been in userspace.

    2. Re:X from user space by Anonymous Coward · · Score: 2, Informative

      X has always been in userspace.

      That's a serious overstatement.

      X.org runs as root and directly maps parts of the PCI address space into its address space. It has the same amount of raw metal access as the kernel; it's a kernel which runs on top of another kernel.

    3. Re:X from user space by sjames · · Score: 2

      If it runs as a user (even root), it runs in userspace. It is a privileged user, but that's not actually the same thing.

      While not typically done, there is no reason it can't be split into a part that maps the PCI device and a part that requests specific access to those parts.

      If you can put up with a performance loss, Xorg CAN be run on top of the framebuffer device as non-root. This ha been doable for years.

  8. Re: acceleration by Kjella · · Score: 2

    It's not quite as bad as it sounds, the actual hardware drivers are still accelerated and exposed as OpenGL, it's just that XWayland doesn't make use of it. If you look at this diagram it's the line between the X-server and libDRM that's broken when you use XWayland instead because Wayland can't talk directly down to that level. XWayland needs to be rewritten to accelerate graphics using OpenGL instead, then it'll hook into the green box above libDRM and all will be well. Luckily for the Wayland project so does the X-server want to as well, "Glamor" that they talk about is essentially 2D X11 over OpenGL.

    Old:
    X-client --> X-server --> libDRM --> hardware
    Old using Wayland:
    X-client --> XWayland --> (broken, software fallback) --> hardware

    New in X-server:
    X-client --> X-server (Glamor) --> OpenGL --> libDRM --> hardware
    New using Wayland
    X-client --> XWayland (Glamor) --> OpenGL --> libDRM --> hardware

    Long term it looks like the plan is to expose everything via OpenGL/OpenGL ES for rendering and EGL for the windowing system so the direct link between X11 and libDRM would go away. That is still a few years off though.

    --
    Live today, because you never know what tomorrow brings
  9. Re: acceleration by dbIII · · Score: 3, Insightful

    This again? Two guys that worked on bits of Xorg are not collectively "the X developers". There are plenty of others out there working on stuff other than a nice tear free framebuffer for a phone. There are plenty of others that don't laugh at "running that app from 1996", who don't laugh at shaped windows, who don't bite the hand that is actually adding some wayland support and who have something better than a half finished presentation with no screenshots to show off their work.