Userland depends on ionice idle but default scheduler is "deadline".
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Triaged
|
Wishlist
|
Rohan Garg |
Bug Description
Userland depends upon the idle feature of the CFQ scheduler, this can lead to extreme desktop sluggishness with the default deadline scheduler due to IO blocking.
In my case, the KDE baloo indexer was indexing all of my files, and making other desktop processes block. The baloo processes are set to idle IO priority to avoid this problem but this was not being honored.
From the information I have found online and in the ionice man page, the idle priority only is useful with the CFQ scheduler.
KDE Baloo indexer sets it's processes to use "idle" priority
the man-db cronjobs also use idle priority
root@sirius:/etc# grep idle cron.daily/man-db
iosched_idle=
iosched_
--oknodo --chuid man $iosched_idle -- -c \
The compiled in default scheduler is "deadline"
root@sirius:/boot# grep DEFAULT_IOSCHED config-
CONFIG_
from the ionice man page:
Linux supports I/O scheduling priorities and classes since 2.6.13 with the CFQ I/O scheduler.
root@sirius:/boot# uname -a
Linux sirius 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 19:11:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-generic 3.13.0.24.28
ProcVersionSign
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
/dev/snd/
CurrentDesktop: KDE
Date: Sun Apr 20 17:23:28 2014
HibernationDevice: RESUME=
InstallationDate: Installed on 2014-04-18 (2 days ago)
InstallationMedia: Kubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.1)
MachineType: Acer Aspire 7551
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.127
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/26/2010
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: V1.15
dmi.board.
dmi.board.name: Aspire 7551
dmi.board.vendor: Acer
dmi.board.version: V1.15
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.
dmi.modalias: dmi:bvnPhoenixT
dmi.product.name: Aspire 7551
dmi.product.
dmi.sys.vendor: Acer
This change was made by a bot.