[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: Fedora-10 nightmare update2



Arne Chr. Jorgensen wrote, On 04/17/2009 03:02 PM:
hi,

I did describe noise/glitches on the screen.

I will try to describe it a little bit: ---------------------------------------

It is like an old CRT with a weak
high voltage supply - the screen may shrink or expand. And there are noise
streaks across the screen.

As this is a laptop with LCD, it has to do with updating of the screen. Loading is typical if you open a folder on the screen, and it will update/paint to the screen. In such cases the shrinking/expansion may be
20-40 mm for a brief half second or so. Sometimes leaving a horizontal band
for in the middle. The reason:
-----------

The "new" cpu scaling can not keep up. I have it set to "on-demand".
 800MHz - worst, as described above.
1600MHz - very improved, the shrinking/expanding is only 5-10 mm 1800MHz - the effect seem gone.
2000MHz - have not seen any noise/glitches.


Discussion:
-----------

Watching the System Monitor, the graphs are smooth, the loading on CPU1 and
CPU2 seem nice compared to earlier kernels with abrupt switching from one
to the other.
<SNIP>

To remove noise on the screen, perhaps a sharper controller term could be
used, at the cost of the more smooth behaviour it has now. Perhaps the
refresh of the screen could be held off/protected during scheduling. I don't know.
Knowing some reasons for this and if need be, just enable a higher prosessor speed, works for me.

//ARNE

Question:
if you do
taskset -p 0x00000002 \
 `ps aux |grep /usr/bin/Xorg| \
  grep -v grep |awk '{print $2}'`

{painful way to get the X pid to feed to taskset, which suggests to the kernel keep the X process on the second processor.}

and then run your tests, does the problem seem less troublesome at the lower speeds?


--
Todd Denniston
Crane Division, Naval Surface Warfare Center (NSWC Crane)
Harnessing the Power of Technology for the Warfighter


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]