A severe performance degradation while syncing md raid after the upgrade to 15.10
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Triaged
|
High
|
Unassigned |
Bug Description
I run Ubuntu from the fakerade (imsm) raid5 volume. If the volume is syncing, the system response is severely degraded. There is no problem if I boot the same system from the previous kernel 3.19.0-32. Some numbers:
[md125_resync] kernel thread CPU consumption: 94 per-mill compared to 10 in 3.19 kernel
[md125_raid5] kernel thread CPU consumption: 243 per-mill compared to 86 in 3.19 kernel
1MB direct read from md array: 0.5s compared to 0.01s in 3.19 kernel
1MB direct read from md raid member: 2.2s compared to 0.02s in 3.19 kernel
As a result, it's practically impossible to work in 4.2 kernel if md raid is syncing (even the boot takes several minutes here), whereas in 3.19 I don't feel any performance degradation at all, regardless the raid volume is syncing or not.
ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: linux-image-
ProcVersionSign
Uname: Linux 4.2.0-22-generic x86_64
NonfreeKernelMo
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
/dev/snd/pcmC0D0p: palo 3869 F...m pulseaudio
/dev/snd/
CurrentDesktop: Unity
Date: Thu Jan 7 18:51:39 2016
HibernationDevice: RESUME=
InstallationDate: Installed on 2011-09-16 (1574 days ago)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
MachineType: System manufacturer System Product Name
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.149.3
RfKill:
SourcePackage: linux
UpgradeStatus: Upgraded to wily on 2016-01-02 (4 days ago)
dmi.bios.date: 02/23/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 2102
dmi.board.
dmi.board.name: P5Q-PRO
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: System Product Name
dmi.product.
dmi.sys.vendor: System manufacturer
Changed in linux (Ubuntu): | |
importance: | Undecided → High |
tags: | added: latest-bios-2102 |
This change was made by a bot.