dialog-based applications seem sluggish
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| qemu-kvm (Ubuntu) |
Expired
|
Low
|
Unassigned | ||
Bug Description
Binary package hint: kvm
When running a dialog-based application (such as Ubuntu's text mode installer) within kvm, it feels very sluggish. If I press cursor-down or up, it takes more than a second until the highlighted bar moves up or down.
Typing text in a (dialog) text fields seems ok though.
This is _not_ a bug in the guest, as on a physical machine it is fast and snappy. Moreover, if kvm is run in vnc mode, it is fast and snappy as well
1. > lsb_release -rd
Description: Ubuntu 9.04
Release: 9.04
2. > apt-cache policy kvm
kvm:
Installed: 1:84+dfsg-
Candidate: 1:84+dfsg-
Version table:
*** 1:84+dfsg-
500 http://
100 /var/lib/
1:
500 http://
3. What I expect to happen
Kvm should react immediately at first cursor movement. If for some reason (slow screen updates?), it should only start deferring or dropping updates if the screen update "queue" already has some updates being processed.
4. What happened instead
First screen refresh apparently was already delayed (maybe trying to wait for more in order to batch them together?)
| AlainKnaff (kubuntu-misc) wrote | #1 |
| affects: | kvm (Ubuntu) → qemu-kvm (Ubuntu) |
| Chuck Short (zulcss) wrote | #2 |
| Changed in qemu-kvm (Ubuntu): | |
| importance: | Undecided → Medium |
| status: | New → Confirmed |
| Dustin Kirkland (kirkland) wrote | #3 |
| Changed in qemu-kvm (Ubuntu): | |
| status: | Confirmed → Incomplete |
| importance: | Medium → Low |
| AlainKnaff (kubuntu-misc) wrote | #4 |
| Launchpad Janitor (janitor) wrote | #5 |
| Changed in qemu-kvm (Ubuntu): | |
| status: | Incomplete → Expired |
| AlainKnaff (kubuntu-misc) wrote | #6 |
The problem also exists for bash commandline. Cursor keys are handled with a one-second delay (approx.), whereas other keys are handled immediately.
My previous interpretation was apparently wrong: the problem is not related to any output that the program performs in reaction to receiving the cursor key, but rather to the reception of the cursor key input itself.