Comment 42 for bug 1151622

On 01/06/14 14:02, Christopher M. Penalver wrote:
> tomdean, thank you for testing the v3.13-rc6 mainline kernel. Just to
> clarify, regarding only the issue mentioned in the Bug Description about
> accessing the avrisp2, with avrdude when plugged into the Belking Hub,
> the problem is not reproducible, correct?
>

Correct.

Question: How do I trace/report the slinky scroll?

To demonstrate, open an xterm. Reposition the xterm (grab the top bar
and move the xterm left or right about 1/4 its width). The xterm is
redrawn from the top down, taking on the order or 1 second.

Alternately, open an xterm with a 1000 line buffer. execute ls several
times to put several hundred lines in the buffer. Scroll up (grab the
scroll bar and drag it up). The text in the xterm is displayed like a
slinky scroll.

This effect is not present with kernel 3.2.0-38-generic. But, is
present in kernels 3.2.0-39-generic and later. At least all I have
tested, up to and including:

 > uname -a
Linux P9X79 3.13.0-031300rc6-generic #201312291935 SMP Mon Dec 30
00:37:05 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

With kernels 3.2.0-39-generic and later, top shows Xorg using 70% to
100% of one CPU when demonstrating the effect.

With kernel 3.2.0-38-generic, this is 20% to 30%.

Tom Dean