Bug 386161 - cpu stay slow when running nice >0
Summary: cpu stay slow when running nice >0
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Fedora
Classification: Fedora
Component: cpuspeed
Version: 8
Hardware: x86_64
OS: Linux
low
low
Target Milestone: ---
Assignee: Jarod Wilson
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2007-11-16 02:43 UTC by Mélanie Legault
Modified: 2007-11-30 22:12 UTC (History)
0 users

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2007-11-20 20:28:39 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Mélanie Legault 2007-11-16 02:43:21 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.9) Gecko/20071105 Fedora/2.0.0.9-1.fc8 Firefox/2.0.0.9

Description of problem:
cpu speed stay at 1.60 GHz (2.13 GHz Core2Duo) and wont go to full 2.13 when running programm with nice setting > 0 (ie nice -n 1). 

still want full power to application when not doing anything else but leave priority to other application

running the same application on different data on each core.

Version-Release number of selected component (if applicable):
cpuspeed-1.2.1-3.fc8

How reproducible:
Always


Steps to Reproduce:
1.nice -n 1 application1
2.nice -n 1 application2
3.

Actual Results:
processor usage go to 100% speed stay at 1.6 GHz

Expected Results:
speed switch to 2.13GHz as was the case if F7 

Additional info:

Comment 1 Jarod Wilson 2007-11-20 20:28:39 UTC
This behavior is controlled by the the value of
/sys/devices/system/cpu/cpu[0-9]*/cpufreq/ondemand/ignore_nice_load, which it
would appear you have set to 1.

Sounds like basically what you want to do is flip the ignore_nice_load value to
0 for all your cpus. Documentation/cpu-freq/governors.txt in the kernel source
says the following:

ignore_nice_load: this parameter takes a value of '0' or '1'. When
set to '0' (its default), all processes are counted towards the
'cpu utilisation' value.  When set to '1', the processes that are
run with a 'nice' value will not count (and thus be ignored) in the
overall usage calculation.  This is useful if you are running a CPU
intensive calculation on your laptop that you do not care how long it
takes to complete as you can 'nice' it and prevent it from taking part
in the deciding process of whether to increase your CPU frequency.

This should be configurable via the IGNORE_NICE param in
/etc/sysconfig/cpuspeed, so just bounce cpuspeed after changing the value and
you should be all set.

Of course, my own system has IGNORE_NICE=0 in its config file, and the actual
system state was 1 until I restarted cpuspeed a minute ago, so something else
may be amiss too... (I'm wondering if gnome twiddles that at all). But I'm
pretty sure there's not a bug in either cpuspeed or the kernel.


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