[lkml]   [2004]   [Jan]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: xterm scrolling speed - scheduling weirdness in 2.6 ?!
On Sun, 4 Jan 2004 14:32, Tim Connors wrote:
> > 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?
> AFAIK the definition of jump scrolling is that if xterm is falling
> behind, it jumps. Jump scrolling is enabled by default.
> What this slowness means is that xterm is getting CPU at just the
> right moments that it isn't falling behind, so it doesn't jump - which
> means X gets all the CPU to redraw, which means your ls/dmesg anything
> else that reads from disk[1] doesn't get any CPU.
> Xterm is already functioning as designed - you can't force jump
> scrolling to jump more - it is at the mercy of how it gets
> scheduled. If there is nothing more in the pipe to draw, it has to
> draw.
> These bloody interactive changes to make X more responsive are at the
> expense of anything that does *real* work.

Harsh words considering it is the timing sensitive nature of xterm that relies
on X running out of steam in the old scheduler design to appear smooth.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:59    [W:0.123 / U:3.624 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site