Question about the future of Xorg

[Robert Heller]

Please take me off the CC list for this thread.




At Fri, 13 Jun 2025 20:34:59 -0400 (EDT) Vladimir Dergachev <volodya at mindspring.com> wrote:

> 
> 
> 
> On Sat, 14 Jun 2025, Carsten Haitzler wrote:
> 
> >>
> >> This is a Dell, it has an integrated Intel GPU and and NVidia one. I
> >> usually don't use NVidia GPU - too much heat and no visible benefit.
> >>
> >> The NVidia chip is Geforce MX 130, 2 GB RAM.
> >
> > what intel chip/gpu?
> 
> Intel Core i7-8550U
> 
> >>
> >> I found that restarting kwin and restarting plasmashell helps, and also
> >> occasionally I kill firefox and restart it. The latter is a nuisance,
> >> because while it does try to restore windows and tabs it does not restore
> >> all of them.
> >
> > this smells of some kind of leak? where? ... dunnos.
> 
> Could be a leak, could be entropy (like fragmentation in memory).
> 
> >
> >> Btw, if you have the same problem there is a setting in about:config
> >> that lets you increase timeout for reaching website. When you restart
> >> firefox and it tries to open 300 windows with 10-15 tabs each, the urls
> >> will timeout too early in default configuration. Change that setting fixes
> >> it (mostly).
> >
> > i never restore tabs... when i close my browser.. i'm done. :)
> 
> Except that nowadays you cannot easily run more than one browser instance.
> 
> Somehow there is a drive to turn every app into an operating system. 
> Firefox has "about:processes" to let you find out what each window and tab 
> are doing because it all gets lumped irregularly by top.
> 
> >> What's your screen resolution? Mine is 3840x2160, so a single full screen
> >> buffer should be 33MB. A few hundred buffers and you would be out of RAM
> >> on discrete GPU (and way earlier on my NVidia chip).
> >
> > 2560x1440. i do have 16gb ram on the card - but ... how many windows do you
> > have normally around... and are they all "maximized" ? as it's a window that
> > consumes a buffer.
> 
> Firefox is usually maximized. I think right now I have around 120 Firefox 
> windows.
> 
> >
> >>> what's your working style? put 50+ windows on a single desktop and "alt+tab"
> >>> between them?
> >>
> >> I got 8 virtual screens, and a bunch of windows on each of them. Most are
> >> firefox.
> >
> > and how many ffox windows?
> >
> >> What happens is that I work on something and it usually involves 10-20
> >> windows, but then I have to pause or wait for one reason or another and
> >> I switch to something else.
> >
> > 10-20 is not too much. and at your fullscreen 33m per window that's ~300-700m -
> > so not a problem for memory usage. even if you run out of vram the gpu can
> > migrate some buffers/textures to system ram and map them over the pcie bus as
> > render targets. its a bit slower. it might not migrate and just alloc new
> > buffers there never migrating lesser used ones off. that'd be a "poor caching
> > algorithm" :)
> 
> It's 10-20 times the number of different things I work on. So it adds up.
> 
> >
> >> It is very convenient that I just leave things as they are and then I just
> >> come back and pick up where I left off. Often I minimize the windows
> >> because I only got 8 virtual screens - its a compromise for space in KDE
> >> panel.
> >>
> >> Looking at xrestop right now, kwin has 69 pixmaps and uses 2.7GB RAM,
> >> while firefox has 276 pixmaps and only 300MB RAM. There are a bunch of
> >> other windows, mostly konsole. Compositing is on right now. I am pretty
> >> sure firefox has a lot more than 69 windows.
> >
> > you said like 10-20 windows above?
> 
> No, no, not 10-20 total, but 10-20 at a time. So I am using 10-20 windows, 
> and another 100 or more I'll return to later.
> 
> I think I counted around 120 firefox windows right now (not tabs, many of 
> the windows have multiple). I am travelling, so fewer than usual.
> 
> 
> > 69 windows? or 69 tabs? i just opened 18
> 
> Actually I got it wrong - the KDE Plasma has 69 pixmaps, kwin has 199. I 
> don't know what kwin uses pixmaps for, but I would imagine it needs at 
> least one per window.
> 
> > maximized terminals. also have this email client (2 windows) plus hexchat +
> > chromium ... e uses about 330m with 25 pixmaps but reality is pixmaps are
> > really only for the windows and nothing else - everything else is rendered
> > inside the compositor with gl (or software) and thus is part of texture
> > atlases etc. nvtop says e uses 440m of video memory which makes sense
> > (2 screens, each 2560x1440). it'd be 270m just for the terminal textures mapped
> > in (shared between x and the client and compositor), as well as wallpaper,
> > other icons/buffers and backbuffers for rendering (90m for backbuffers for both
> > screen if triple buffered). so all in all 440m doesn't sound wrong to me.
> 
> 18 terminals are too small a test. Does it work if you open 1000 ?
> 
> It makes sense that if you expect users to have no problem handling 100 
> windows, you need to test with at least an order of magnitude more.
> 
> >>>
> >>> they are the same really as a composited x11. no real difference at all.
> >>
> >> Naively, if all the windows always have a buffer than 8GB GPU can only
> >> afford 242 4K windows. And you don't get more memory in consumer GPUs
> >> because they will then compete with AI market devices.
> >
> > ??? the default for consumer gpu's is 16g these days. 8g is a low end "cut
> > price" gpu. the latest gen of gpu's is now more pushing towards 24/32g.
> 
> They are all "cut price" right now - you cannot buy 24/32gb, at least in 
> stores near me. The companies do this on purpose for market segmentation.
> 
> And on a notebook the RAM and bandwidth are even smaller.
> 
> Also, right now Microsoft is very busy alienating a lot of people with 
> computers without TPM that cannot upgrade to new Windows version.
> 
> Those people are happily installing Linux and we should not impose 
> requirements of more than 8GB video RAM just to open some webpages.
> 
> >>> if its a 1-off "screenshot then display a copy of it and just scale that up"
> >>> then there are wayland protocols for that - but the idea is that
> >>> screenshotting protocol access will be limited and a compositor may do a
> >>> very android/ios thing of ask you to grant permission first.
> >>
> >> I hate the permission stuff on android. The worst is that they've taken to
> >> removing permissions from apps when you don't use them. So you have some
> >
> > so you're happy with rogue games you run screenshotting your browser with
> > banking details and sending it back to home? :)
> 
> This problem only arises on Android and IOS because they are designed for 
> closed source apps and for controlling the user.
> 
> On Linux there is no such problem as long as you use software you can 
> examine.
> 
> On Android you could improve things immeasurably if open source apps were 
> installed with complete user access to app directory (to check which 
> binary actually shipped) and no permission restrictions.
> 
> >
> > that's the point of this. the point is that the display system should stop
> > being a leak of info/security. it cant force you to sandbox apps... but it can
> > STOP being the problem that makes sandboxing ineffective.
> 
> I would actually argue that X is very secure, and gotten more secure over 
> the years.
> 
> Why? Because before 2000 you often had multiple users on the same system. 
> And now I have several systems and I am the only user. They are on the 
> same network that I control, and there is no way to access those sessions.
> 
> The only potential problem comes from Firefox, and is really mostly due to 
> javascript. And, as I see, Firefox developers (and authors of uBlock 
> and noScript) are on top of it.
> 
> >
> >> app that you use once a month and then you have to debug why it does not
> >> work. Especially sucks if you need to take a quick snapshot with a thermal
> >> camera or a similar tool.
> >
> > and this is the current problem area - how to grant permission AND keep it
> > granted persistently.
> 
> It is a very simple problem - you have an xmag/kmag like app. You examine 
> code. You see it does not send screenshots to some random IP or random 
> country. You install it and use with no restrictions.
> 
> Same goes for screenshot app, WaylandVNC (if it exists), screen recorder 
> and so on. And you can let Neko run around your screen as well.
> 
> >> A lot of it is pointless anyway - the apps that do shady stuff will find a
> >> way anyway, and the users of good apps are just getting annoyed.
> >
> > and on the flip side if you go to a lot of effort to sandbox an app in a
> > container or a smack label (read up on them) that then quite effectively limits
> > that app - the display system is a massive leaking hole you cant plug... and
> > this is one of the things wayland wants to address and does.
> 
> My number one step now after installing Kubuntu is to "de-snap" Firefox 
> and install a debian package.
> 
> >> Screenshot is not perfect - you really want a video, so you can play an
> >> animation.
> >
> > a screenshot is just 1 frame of a video... that is how zoom, teams and every
> > video conf app works now today. they keep taking screenshots repeatedly and
> > quickly. that's how they can "share my screen" over that video conference...
> > they grab these frames then encode them into a video stream - on the fly. they
> > do that in x11 today...
> 
> Yes, but ideally you could do it in such a way as to guarantee a frame 
> every 1/N seconds and also guarantee that a frame is fully rendered to 
> avoid tearing. This is something that I think X cannot do right now.
> 
> >
> >> Another useful tool is screen recorder like vokoscreenNG - with it you can
> >> record your talk to be played back later. Again, you want the ability to
> >> record a video of the screen.
> >
> > guess how those work too... :) see above :)
> 
> I was just giving an example of apps you want to have full screen access.
> 
> >
> > then this is certainly something your vnc viewer should support IMHO. as how
> > much you want to scale THAT session may vary from target to target it is
> > connecting to... and it should remember such scale settings machine by machine
> > you register/connect to. the compositor has no clue what is inside that app's
> > window. in wayland or x11. it's the app's business.
> 
> Not really - I just run x11vnc on the remote and connect to it. I don't 
> start a new session, and I don't change fonts. Very handy, both to help 
> someone else and to use your desktop when you are away.
> 
> best
> 
> Vladimir Dergachev
> 
>                                                                                                                                
> 

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