Messages in this thread | | | Date | Sat, 31 Mar 2001 02:53:42 +0200 | From | Pavel Machek <> | Subject | Re: fbcon slowness [was NTP on 2.4.2?] |
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Hi!
> > >Are you using fbcon? If so, and if it goes away after starting X, then it > > >is the "fbcon kills interrupt latency" problem. > > > > Ug!!! This is getting bad. Give me some time. I plan on releasing a new > > vesafb using MMX to help speed up the drawing routines. It will help alot > > with the latency issues. I also know using ARM assembly we can greatly > > reduce the latency issues. > > On console speedups: back in the old days, scrolling a subregion of the > text console to be _really_ slow on some machines. I am talking about > text mode now, not framebuffer mode. On some cards, text mode is > actually very very slow and the framebuffer is faster. It took *2 > seconds* to scroll a 50 lines of text 50 times on my 200MHz PPro system > 4 years ago. So less "back one screen" took 2 seconds. And Emacs uses > "scroll region by N lines" a lot. In those days, "N lines" scrolls > actually did N x 1 line scrolls, so text mode was really a burden on > that machine. I took to using X, with a single screen size xterm to > present the illusion of console mode. > > Well, nowadays on my laptop we have the joy of the framebuffer console. > Nice penguin aside, it means I get a console on the full screen area. > > But it is nearly as slow at scrolling as my old 200MHz PPro.
You have same toshiba satellite as me, right?
> Probably the lack of hardware area copies has something to do with > this. However, who isn't familiar with xterm "jump scroll" mode? > That's nice and fast. > > Could such a thing be implemented in the console driver?
I believe so. It would be simple: if there's too much activit, defer framebuffer updates and only update in-memory copy. Sync from time to time. I'd certainly like to see that. Pavel -- The best software in life is free (not shareware)! Pavel GCM d? s-: !g p?:+ au- a--@ w+ v- C++@ UL+++ L++ N++ E++ W--- M- Y- R+ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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