Significant performance regression in 2.6.28-8.24 due to p4-clockmod
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
High
|
Scott James Remnant (Canonical) |
Bug Description
On upgrading to kernel 2.6.28-8.24, I noticed a very significant regression in the responsiveness of desktop applications: firefox became unreasonably slow to load pages, and screen redraws for things like switching tabs in xchat, gnome-terminal etc. went from being to instantaneous to taking a human-visible amount of time to process.
Adding the cpufreq panel applet revealed that my CPU was scaled back from 3GHz to 375MHz, and being excessively conservative about scaling up under load. Resetting to the performance governor cured the problem.
I suggest that the ondemand governor in some hardware may not be a viable default.
ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 9.04
MachineType: Supermicro P8SAA
NonfreeKernelMo
Package: linux-image-
ProcCmdLine: root=LABEL=epsilon ro ht=on
ProcEnviron:
LC_COLLATE=C
PATH=(custom, user)
LANG=en_GB.UTF-8
SHELL=/bin/bash
ProcVersionSign
SourcePackage: linux
The following may be in some way related, but not necessary complete duplicates:
bug 326149
bug 122993
bug 231856