Re: xterm scrolling speed - scheduling weirdness in 2.6 ?!

[Con Kolivas <kernel@kolivas.org>]

On Sun, 4 Jan 2004 10:35, Willy Tarreau wrote:
> 6) Conclusion
> =============
>
> Under 2.4, xterm uses jump scrolling which it does not use by default under
> 2.6 if X responds fast enough. The first dirty solution which comes to mind
> is to renice X to >+10 to slow it a bit so that xterm hits the high water
> level and jumps.
>
> But it's not an effect of the scheduler alone, but a side effect of the
> scheduler and xterm both trying to automatically adjust their behaviour in
> a different manner. 

Not quite. The scheduler retains high priority for X for longer so it's no new 
dynamic adjustment of any sort, just better cpu usage by X (which is why it's 
smoother now at nice 0 than previously). 

> If either the scheduler or xterm was a bit smarter or 
> used different thresholds, the problem would go away. It would also explain
> why there are people who cannot reproduce it. Perhaps a somewhat faster or
> slower system makes the problem go away. Honnestly, it's the first time
> that I notice that my xterms are jump-scrolling, it was so much fluid
> anyway.

Very thorough but not a scheduler problem as far as I'm concerned. Can you not 
disable smooth scrolling and force jump scrolling?

Con