Wayland - Beyond X (The H)

Posted Feb 14, 2012 19:41 UTC (Tue) by drag (guest, #31333)
In reply to: Wayland - Beyond X (The H) by daglwn
Parent article: Wayland - Beyond X (The H)

> No, it won't. It will be able to run an X server as a client. That's not the same thing.

It will be able to connect and display X clients. That's X11 networking.
Why is it such a surprise that it's going to run a program to provide X functionality?

It's like saying you can't browse the web with Wayland because you need to use a web browser.

> The whole point of Wayland is to get rid of X, isn't it?

No.

The whole point of Wayland is to provide a modern and relatively easy to platform for writing graphical programs. It will provide the ability for application developers to use direct rendering for their applications using whatever method or API is best suited for the application or the audience.

This is something that is not possible with XFree DDX we use today and X11 is one of those methods that application developers can choose to use.

It only intends to get rid of the need of XServer running you hardware. You can still have your XServer.

Saying that Wayland is intended to get rid of X11 is like saying that Wayland intends to do away with HTTP.

> If not, then what is the point? I'm not opposed to dumping X, but the replacement has to be fully functional and that includes network transparency.

Ok?

Trying to putting it into perspective:

I have 'network transparency' with Windows 7. I don't know why people that is X11 is so special or so required if you want to use remote applications.

It's not the only game in town and it's been a VERY VERY long time since it was even a good one. The world has moved on. The reason is that we still have relatively high latency links. We have lots of bandwidth that is plenty for running remote applications, however latency have not dropped by the same amount. Latency is what kicks X11's ass and is something that X11 is very poor at dealing with. All of which means that X11 is not suitable solution for what most people use remote apps for... which is things like implementing VDI and accessing applications over the internet over high latency links.

Keep in mind a _A_LOT_ of people use remote apps. My dad uses remote apps. 90% of people at my work use remote apps. Teachers, students, accountants.. all sorts of people use networking for remote GUI apps. They just don't use Linux, nor do they use X11 to do it.

Maybe X12 will make it useful once again. But keep in mind that it's going to be a lot easier to implement X12 support on top of Wayland then it's going to be with Xfree. This is because you can easily keep your backward compatibility with a X11 server integrated in Wayland while vastly reducing the overhead needed to implement a X12 server...

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Wayland - Beyond X (The H)

Posted Feb 14, 2012 19:45 UTC (Tue) by dlang (guest, #313) [Link] (1 responses)

>> No, it won't. It will be able to run an X server as a client. That's not the same thing.

> It will be able to connect and display X clients. That's X11 networking.
Why is it such a surprise that it's going to run a program to provide X functionality?

make it possible to run a Wayland app and display it on an X display and you have what people need.

Then we can talk about the efficiency and performance of the Wayland remote capability. If all it does is shove full-resolution screenshots to the X display, it's not going to work very well.

Wayland - Beyond X (The H)

Posted Feb 14, 2012 23:19 UTC (Tue) by nix (subscriber, #2304) [Link]

make it possible to run a Wayland app and display it on an X display

That's not that important. What matters is two things, really:

- That an X11 client for Wayland exists such that a Wayland server can display remote (and local) X apps. This seems overwhelmingly likely to be written or the transition process would be impossible. (It also seems likely that such a client would be transparently-started and per-window, making X apps look indistinguishable from native Wayland apps).

- That something exists such that remote Wayland clients can be displayed on local Wayland servers with reasonable efficiency (comparable to or better than current X, not giant bitmap-hurling horrors like VNC). So far I have received a mass of conflicting opinions regarding whether this is desirable or even possible. If this is implemented as a bunch of toolkit-level hacks, then I very much hope that no applications ever come to support Wayland except via those toolkits, because Wayland apps that only work locally will break the illusion that all machines are one machine that I very much value. (X is surprisingly good at this. I've watched full-motion 1680x1050 video over X connections on gigabit ethernet and it's worked so well that I didn't notice that I was running remotely until the video ended. It falls over in a heap if SSH tunnels are involved, of course -- SSH just can't transfer that much information that fast, nor was it ever designed to.)

Wayland - Beyond X (The H)

Posted Feb 14, 2012 20:06 UTC (Tue) by khim (subscriber, #9252) [Link] (4 responses)

It's even worse:

The reason is that we still have relatively high latency links. We have lots of bandwidth that is plenty for running remote applications, however latency have not dropped by the same amount.

Yup. Exactly. What's worse: in the future situation will go from bad to worse, the to the worst.

Imagine how the state of the art XXV century technology will look like. Bandwidth will probably be astronomical. Enough to shove 7680×4320 frames 120 times per second and more. Latency... Worst-time latency will still be 67ms on average, 133ms worst case. Calculations are trivial: 20000km-40000km round-trip (average 20000km, worst case 40000km), 300000km/sec, you do the math.

Why people still are trying to invent stupid schemes to reduce bandwidth requirements by adding more round-trips is beyond me: these schemes will be useless pretty soon, why try to add them to the new protocol?

Wayland - Beyond X (The H)

Posted Feb 14, 2012 23:05 UTC (Tue) by Cyberax (✭ supporter ✭, #52523) [Link]

Well, unless we get FTL :) Those guys with neutrinos are clearly up to something.

But yeah, light-speed lag is going to the limiting factor for a long time.

Wayland - Beyond X (The H)

Posted Feb 14, 2012 23:26 UTC (Tue) by nix (subscriber, #2304) [Link] (1 responses)

Worst-time latency will still be 67ms on average, 133ms worst case

Hah. I wish. I use X (a bit, it is too slow to be useful most of the time) from my parents' house, in the wilderness, a whole ten miles from a major tourist spot in Yorkshire, so obviously the back of beyond (that's millions of centimetres, nobody could hope to string a cable that far). Satellite link to geosynch and back, then down to Italy, then back to England. 660ms RTT. This is the only broadband they are likely to get for at least the next twenty years. And they are relatively lucky: at least they didn't have a hill stopping them from seeing geosynch. What people in the Scottish highlands are doing for connectivity I have no idea, but it is probably not pleasant.

I don't expect any remote display protocol to cope with that sort of latency.

Why people still are trying to invent stupid schemes to reduce bandwidth requirements by adding more round-trips is beyond me: these schemes will be useless pretty soon, why try to add them to the new protocol?

Who on eath is trying to do that? Reducing round-trips has been core to X protocol optimization since the start: anyone trying to increase them (excepting only perhaps do-only-once stuff which is amortized to zero) is a nutter. However, not even local network bandwidth is yet free, and with 10GbE equipment at the cost it is now ($4000 for a basic switch!) I'd expect a long long wait before that becomes common enough that we can consider that it is even ten times cheaper than it is now.

Wayland - Beyond X (The H)

Posted Feb 15, 2012 0:42 UTC (Wed) by Cyberax (✭ supporter ✭, #52523) [Link]

>I don't expect any remote display protocol to cope with that sort of latency.

But RDP can do this, it'll be uncomfortable but usable. I had to use RDP a couple of times on congested GPRS/EDGE links with similar latencies.

Wayland - Beyond X (The H)

Posted Feb 15, 2012 19:02 UTC (Wed) by alankila (guest, #47141) [Link]

We should seriously study if we could just radiate information on tight beam straight through the Earth, presumably through some kind of fixed networking stations. Might get that worst-case latency down to 12000 km light time (40 ms). At least some particles are going to pass through Earth; difficulty may lie in both generating them headed to the right direction, and with detecting them...