Enable intel_pstate by default on Trusty EC2 AMIs
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
In Progress
|
Medium
|
Unassigned |
Bug Description
Please can the intel_pstate driver be enabled by default on the Ubuntu EC2 AMIs. On instances with support for C-states and P-States [1] there is a notable performance impact and lack of support for higher clock frequencies available due to the use of the acpi-cpufreq driver. For example on a c4.8xlarge the default frequency is limited to 2.9GHz when 3.2GHz is supported by the chip [2]. Some additional analysis is available here [3] and re-enabling it by default has been discussed [4] but this request is specifically for the EC2 AMIs.
[1] http://
[2] http://
[3] http://
[4] https:/
AMI: ami-47a23a30 (eu-west-1)
$ lsb_release -d
Description: Ubuntu 14.04.2 LTS
$ uname -a
Linux ip-172-31-8-218 3.13.0-57-generic #95-Ubuntu SMP Fri Jun 19 09:28:15 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
Default configuration (c4.8xl):
$ sudo cpupower frequency-info
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 1.20 GHz - 2.90 GHz
available frequency steps: 2.90 GHz, 2.90 GHz, 2.80 GHz, 2.70 GHz, 2.50 GHz, 2.40 GHz, 2.30 GHz, 2.20 GHz, 2.00 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 1.20 GHz and 2.90 GHz.
current CPU frequency is 1.20 GHz (asserted by call to hardware).
cpufreq stats: 2.90 GHz:70.40%, 2.90 GHz:0.00%, 2.80 GHz:0.00%, 2.70 GHz:0.00%, 2.50 GHz:0.00%, 2.40 GHz:0.00%, 2.30 GHz:0.00%, 2.20 GHz:0.00%, 2.00 GHz:0.00%, 1.90 GHz:0.00%, 1.80 GHz:0.00%, 1.70 GHz:0.00%, 1.60 GHz:0.09%, 1.40 GHz:0.00%, 1.30 GHz:0.00%, 1.20 GHz:29.51% (5)
boost state support:
Supported: yes
Active: yes
With intel_pstate enabled (c4.8xl):
$ sudo cpupower frequency-info
analyzing CPU 0:
driver: intel_pstate
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 0.97 ms.
hardware limits: 1.20 GHz - 3.50 GHz
available cpufreq governors: performance, powersave
current policy: frequency should be within 1.20 GHz and 3.50 GHz.
current CPU frequency is 3.20 GHz (asserted by call to hardware).
boost state support:
Supported: yes
Active: yes
---
AlsaDevices:
total 0
crw-rw---- 1 root audio 116, 1 Aug 12 17:19 seq
crw-rw---- 1 root audio 116, 33 Aug 12 17:19 timer
AplayDevices: Error: [Errno 2] No such file or directory
ApportVersion: 2.14.1-0ubuntu3.11
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CRDA: Error: [Errno 2] No such file or directory
CurrentDmesg: [39221.196411] init: plymouth-
DistroRelease: Ubuntu 14.04
Ec2AMI: ami-47a23a30
Ec2AMIManifest: (unknown)
Ec2Availability
Ec2InstanceType: c4.8xlarge
Ec2Kernel: unavailable
Ec2Ramdisk: unavailable
IwConfig: Error: [Errno 2] No such file or directory
Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize libusb: -99
MachineType: Xen HVM domU
Package: linux (not installed)
PciMultimedia:
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB:
ProcKernelCmdLine: BOOT_IMAGE=
ProcVersionSign
RelatedPackageV
linux-
linux-
linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory
Tags: trusty ec2-images
Uname: Linux 3.13.0-61-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm audio cdrom dialout dip floppy netdev plugdev sudo video
_MarkForUpload: True
dmi.bios.date: 05/06/2015
dmi.bios.vendor: Xen
dmi.bios.version: 4.2.amazon
dmi.chassis.type: 1
dmi.chassis.vendor: Xen
dmi.modalias: dmi:bvnXen:
dmi.product.name: HVM domU
dmi.product.
dmi.sys.vendor: Xen
affects: | ubuntu-on-ec2 → linux-meta (Ubuntu) |
affects: | linux-meta (Ubuntu) → linux (Ubuntu) |
Changed in linux (Ubuntu): | |
importance: | Undecided → Medium |
tags: | added: kernel-da-key |
Changed in linux (Ubuntu): | |
status: | Confirmed → In Progress |
assignee: | nobody → Colin Ian King (colin-king) |
Changed in linux (Ubuntu): | |
assignee: | Colin Ian King (colin-king) → nobody |
Colin,
I read that you were considering[1] enabling it during t+1 and I wanted your opinion for enabling it in Trusty on EC2 images at this time. Also, what testing were you doing to evaluate this previously? Thanks.
[1] https:/ /lists. ubuntu. com/archives/ kernel- team/2014- April/040795. html