Request increase CONFG_NR_CPUS= higher than 8 for linux-generic-pae
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Won't Fix
|
Wishlist
|
Unassigned |
Bug Description
Binary package hint: linux-generic-pae
In linux-generic-pae 32-bit kernel the config parameter CONFIG_NR_CPUS=8 is set to 8 this is to little for modern multicore CPUs. Suggestion is that this parameter is set to either 32 or 64. CONFIG_NR_CPUS=64 is the value used in the 64-bit kernel.
Steps to reproduce:
$ grep CONFIG_NR_CPUS /boot/config-
./linux-
uname -a output:
Linux ubuntu 2.6.32-
ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-generic-pae 2.6.32.24.25
Regression: No
Reproducible: Yes
ProcVersionSign
Uname: Linux 2.6.32-
AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access /dev/snd/: No such file or directory
AplayDevices: aplay: device_list:223: no soundcards found...
Architecture: i386
ArecordDevices: arecord: device_list:223: no soundcards found...
Date: Tue Aug 24 13:25:34 2010
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100427.1)
MachineType: Supermicro X8DTU
PciMultimedia:
ProcCmdLine: BOOT_IMAGE=
ProcEnviron:
PATH=(custom, no user)
LANG=sv_SE.utf8
SHELL=/bin/bash
SourcePackage: linux
UdevDb: Error: [Errno 2] Filen eller katalogen finns inte
dmi.bios.date: 05/28/2010
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 2.0
dmi.board.
dmi.board.name: X8DTU
dmi.board.vendor: Supermicro
dmi.board.version: 1234567890
dmi.chassis.
dmi.chassis.type: 17
dmi.chassis.vendor: Supermicro
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: X8DTU
dmi.product.
dmi.sys.vendor: Supermicro
affects: | linux-meta (Ubuntu) → linux (Ubuntu) |
Changed in linux (Ubuntu): | |
status: | New → Confirmed |
Christian Nygaard, thank you for reporting this and helping make Ubuntu better. As of Trusty this would still be 8: ubuntu. com/ubuntu/ ubuntu- trusty. git && grep -r CONFIG_NR_CPUS= | grep i386 master/ config/ i386/config. common. i386:CONFIG_ NR_CPUS= 8
git clone git://kernel.
debian.
I'll mark this Triaged for now, so this request could be further reviewed.
As well, could you please provide a full detail on why you are making this request? Is this just a general "it would be nice..." or would you have a requirement in your environment for PAE, that migrating to amd64 would be too onerous?
Despite this, from the perspective of just one data point, if one is utilizing 8+ cores, then it may be best to switch to the amd64 version of the kernel for performance reasons -> http:// www.phoronix. com/scan. php?page= article& item=ubuntu_ x86_1304& num=1 .