On Sun, 15 Jun 2025, Alan Coopersmith wrote:
On 6/14/25 12:45, Vladimir Dergachev wrote:
Imagine consumers using organic led wallpaper to cover walls and expecting
to put windows with pictures, videos and homework there. Suppose you have
low- resolution cheap OLED wallpaper, 96dpi. 5 meters (16ft) will translate
to more than 18000 pixels!
The X11 coordinate space tops out at 32767, so it's not going to scale to
wall
size.
well i couldn't in my std way - i'd run out of x client fd's - the xserver
limits x client count to 128... :) i'd have to enable single process mode
in my
terminal to keep it a single client.
Hmmm - scalability issue. We need to fix that in X :)
If you look in the Xserver(1) man page there's an option already:
-maxclients
64|128|256|512 Set the maximum number of clients allowed
to
connect to the X server. Acceptable values are 64, 128, 256
or
512.
What it doesn't tell you is that there's a tradeoff involved - the X11
resource
id space is divided up into evenly sized chunks per client, so if you go from
128 clients to 256 clients, each of those clients gets half the available
number
of resource ids to use.
Interesting !
I think these limitations in X11 are understable given it dates back to
1980s. Back then 32-bit machines were big.
Nowadays, we can easily solve such limitations with 64-bit fields. Double
the size, but our computers are orders of magnitude faster than in 1980s.
Looks like Wayland has 32-bit surface dimensions - much better.
Since I am the one arguing for scalability, I think I should setup a test
system and check how modern Wayland compositors behave under load. We'll
see how to go forward from there.
Do you know if anyone did equivalent of x11perf test with Wayland?
it once. all those people windows is alienating and try linux certainly
won't
be doing it either.
No need for everyone to do checks.
This is a perfect business case for a distribution like Debian or Ubuntu or
Redhat, which offers pre-checked packages, secured with hash sums.
I doubt any distro checks the source code of all the packages they include
that
closely. I wouldn't be surprised if some of the commits I've pushed to X11
git repos have never been looked at by another human being.
Another example is the SSH issue Debian had a while back. But these kinds
of problems cannot be solved with a popup asking user "Trust SSH or not?"
And the past history shows these issues are discovered relatively quickly.
For an app like xmag, all one needs to do is check that there is no code
trying to send data outside. If there are bugs then the worst thing that
happens is that it crashes.
If people care about security (like I do), they can go a take a look
themselves. One can also have a crowdsourcing like project where people
look at some Debian packages and then we know that specific versions are
checked.
best
Vladimir Dergachev
-Alan Coopersmith- [email protected]
Oracle Solaris Engineering - https://blogs.oracle.com/solaris
