Jaunty Upgrade: Really REALLY sucky performance with rt kernel
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Expired
|
Undecided
|
Unassigned |
Bug Description
This is nebulous, all purvasive and exceptionally annoying, and I don't even know where to begin to debug this, so I'm appealing to those of you who know more about the internals of the specific components.
I upgraded my Dell Inspiron 1521 laptop to 9.04 and the performance is abysmal; this is a dual-core AMD Turion(tm) 64 X2 Mobile Technology TL-60 1795.601MHz, and it is now SLOWER than a P3/300Mhz.
Now here is the kicker: the Live-CD session using the Jaunty Desktop CD is fine, it is quite zippy and enjoyable. So SOMETHING has gone horribly wrong with the upgrade.
but I don't know where to begin to look. Here's what I do know:
Both the Live CD and the upgrade session use the Radeon driver at 1440x900. The chipset is X1200 no longer supported by ATI (I have ranted at them elsewhere) so there is no fglrx installed. The upgrade initially chose the RadeonHD driver, but when I noticed the LiveCD performance was so much better and that it used the plain Radeon, I removed RadeonHD to force the Radeon choice. It didn't make any difference.
Very curiously, the LiveCD session lsmod includes both the radeon and the drm kernel modules whereas the upgraded session does not; when I try to modprobe these modules I get the same error on both:
FATAL: Error inserting radeon (/lib/modules/
also curious, 'free' reports zero shared memory
$ free
total used free shared buffers cached
Mem: 1932460 839556 1092904 0 43236 472764
-/+ buffers/cache: 323556 1608904
Swap: 4088500 0 4088500
in top, Xorg is constantly at the top on an idle machine:
5845 root 20 0 229m 26m 8184 R 78 1.4 13:55.12 Xorg
load average is 1.23 on a session that is only running 'top' and filling in this form
Firefox performance is excruciatingly slow, making the typing into this form very tedious to do :)
one difference: the upgraded machine was Ubuntu Studio, so it is running RT
Linux uhuru 2.6.24-23-rt #1 SMP PREEMPT RT Wed Apr 1 23:40:34 UTC 2009
the liveCD runs
Linux ubuntu 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009
lsmod and Xorg.0.log comparisons attached.
affects: | ubuntu → linux (Ubuntu) |
summary: |
- Jaunty Upgrade: Really REALLY sucky performance + Jaunty Upgrade: Really REALLY sucky performance with rt kernel |
one culprit was the RT kernel installed by Ubuntu-Studio
Linux uhuru 2.6.24-23-rt #1 SMP PREEMPT RT Wed Apr 1 23:40:34 UTC 2009
I removed this and installed Linux uhuru 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 and performance is immediately much improved, Xorg shows drm now installs and radeon and drm are now both in the lsmod listing.
the upgrade apparently misses replacing the RT kernel, which makes sense (in retrospect) since Cannonical does not support the RT kernel images.