FBDEV Console Patches Optimize Performance - Print Directory Listing ~25% Faster

[david-nk]

Still very slow. It takes 0.1s with gnome-terminal and of that only 0.03s are spent in user-space, the rest is spent in the kernel actually finding the files.

[uxmkt]

I don't know how I feel about this. I really hoped the lack of maintainer and loss of functionality would finally give impetus to a userspace solution. Personally, I use kmscon with hwaccel, it's okay, fast enough, looks okay, but really isn't a complete solution and feels unfinished.

There were/are two movements. One is adding more cruft to the most basic non-serial terminal you can get with Linux, and the other is removing cruft from a proper graphics stack.
In the blue corner: There once was the venerable VGA text console. Then hardware started providing a pixel framebuffer, and Linux went to combine its text terminal (vt.c) code with fbdev. Then someone made fbterm, a userspace graphical console bolted onto /dev/fb0. And later, kmscon using the same idea, but now with truetype support.
In the red corner: the old fat X server, with an xterm (or god forbid, a bloated, laggy program, possibly with some GL to produce the looks of a curved surface monitor flickering its green phosphors). Then a lot of fat was cut, so to speak, with Wayland. Make the terminal fullscreen, you could almost forget there even was a Wayland session.
The red option is almost as lightweight as the blue option now being fat. And at least for me, that explain's the stopped work on kmscon.

[ypnos]

Glad to see scrolling coming back. When I noticed it was removed it as a real WTF moment...

Don't rejoice too soon. Scrolling is a feature of the vt, this is only about fbdev. The optimization here is related to how fast the whole screen scrolls up when a new line is appended. Not about manual scrolling which was removed due to security concerns.

[sinepgib]

/dev/fb0
It also can display graphics if user has write permission to it. I think Links (webbrowser) can use it too and maybe SDL so games can work without X11 or root access.
Screenshots can be taken with cat /dev/fb0 > image.raw

Qt also has a backend for embedded uses. kmscon does as well, despite what its name implies.

[Etherman]

Would anybody be able to ELI5 this to me? What is FBDEV?

Is it what a TTY uses to display stuff?

/dev/fb0
It also can display graphics if user has write permission to it. I think Links (webbrowser) can use it too and maybe SDL so games can work without X11 or root access.
Screenshots can be taken with cat /dev/fb0 > image.raw

[sdack]

Ha. To this day, devs give me weird looks when I tell them it's faster if they don't actually print the output...

Probably because you misunderstand the goal. It is not about how fast one can scroll thousands of lines. You are obviously right that not printing the entire content is a lot faster. It is about printing a single line. Listing the content of /usr/share/doc is merely used as a means to benchmark the optimization.

[sinepgib]

With as much as we discuss it I'm really surprised the Phoronix community hasn't hacked something together by now.

Considering how many of its members are just lazy haters that wouldn't release a line of code but are constantly bitching about the ones who do not doing things as they want them, I'm not surprised in the slightest. Just a few posts above yours is the most retarded take one can have.

[skeevy420]

I don't know how I feel about this. I really hoped the lack of maintainer and loss of functionality would finally give impetus to a userspace solution. Personally, I use kmscon with hwaccel, it's okay, fast enough, looks okay, but really isn't a complete solution and feels unfinished.

With as much as we discuss it I'm really surprised the Phoronix community hasn't hacked something together by now.

[bobbie424242]

Glad to see scrolling coming back. When I noticed it was removed it as a real WTF moment...

[er888kh]

This is really nice - I was allways wondering why CPU, RAM, IOs get so much faster but often you can't "feel" this in console. Still more or less like the first time on a fast SSD. Or am I missing something?

Unless you use an electron based terminal. Honestly, I am way more grateful after opening one 2 times and using it for 5 minutes.