Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
cpu sometimes very slow
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Kernel & Hardware
View previous topic :: View next topic  
Author Message
ccube
n00b
n00b


Joined: 15 Feb 2011
Posts: 66

PostPosted: Wed Nov 28, 2012 11:22 am    Post subject: cpu sometimes very slow Reply with quote

Hey folks,
i've got a dell studio 1558 notebook with a i7 820qm processor.
sometimes (not always) compiling is very slow and with 100%cpu load it is most of the time in C1 state.
after rebooting the system i can kick the cpu to 100% c0 when burning all cpus with emerge chromium or sth. like that.

what might be wrong here? where to start investigating?


Code:

Cpu speed from cpuinfo 1728.00Mhz
cpuinfo might be wrong if cpufreq is enabled. To guess correctly try estimating via tsc
Linux's inbuilt cpu_khz code emulated now
True Frequency (without accounting Turbo) 1728 MHz
  CPU Multiplier 13x || Bus clock frequency (BCLK) 132.92 MHz

Socket [0] - [physical cores=4, logical cores=8, max online cores ever=4]
  TURBO ENABLED on 4 Cores, Hyper Threading ON
  Max Frequency without considering Turbo 1860.92 MHz (132.92 x [14])
  Max TURBO Multiplier (if Enabled) with 1/2/3/4 Cores is  23x/21x/15x/15x
  Real Current Frequency 1993.94 MHz [132.92 x 15.00] (Max of below)
        Core [core-id]  :Actual Freq (Mult.)      C0%   Halt(C1)%  C3 %   C6 %  Temp
        Core 1 [0]:       1993.85 (15.00x)      39.6    54.3       0       0    86
        Core 2 [1]:       1993.87 (15.00x)      76.7    11.5       0       0    90
        Core 3 [2]:       1993.94 (15.00x)      14.9    82.8       0       0    87
        Core 4 [3]:       1993.93 (15.00x)      15.3    82.4       0       0    87



C0 = Processor running without halting
C1 = Processor running with halts (States >C0 are power saver)
C3 = Cores running with PLL turned off and core cache turned off
C6 = Everything in C3 + core state saved to last level cache
  Above values in table are in percentage over the last 1 sec
[core-id] refers to core-id number in /proc/cpuinfo
'Garbage Values' message printed when garbage values are read
  Ctrl+C to exit
Back to top
View user's profile Send private message
audiodef
Watchman
Watchman


Joined: 06 Jul 2005
Posts: 5282

PostPosted: Wed Nov 28, 2012 2:53 pm    Post subject: Reply with quote

Your CPU has four cores. Do you have MAKEOPTS="-j4" in /etc/make.conf or /etc/portage/make.conf?
_________________
Gentoo Studio: http://gentoostudio.org
Facebook: http://www.facebook.com/gentoostudio
G+: https://plus.google.com/113947758237122861689/posts
Pappy's Kernel Seeds: http://kernel-seeds.org
Back to top
View user's profile Send private message
LiamOS
n00b
n00b


Joined: 06 Jun 2012
Posts: 56
Location: Kerry/Dublin, Ireland

PostPosted: Wed Nov 28, 2012 3:44 pm    Post subject: Reply with quote

As mentioned above, MAKEOPTS is something you should have set at -j4, or possibly -j5. Also, check if you have PORTAGE_NICENESS set, as this might have some effects.

Did you configure your kernell yourself? If you have access to a precompiled kernel, you could check if you get the same problems under that. If so, you've ruled out one thing.
_________________
CFLAGS=" -O999999"
Back to top
View user's profile Send private message
ccube
n00b
n00b


Joined: 15 Feb 2011
Posts: 66

PostPosted: Wed Nov 28, 2012 5:26 pm    Post subject: Reply with quote

My CPU has 4 cores hyper threaded, so i set MAKEOPTS to at least 8.
the log i posted was made, while al 8 logic cores were at 100% load.

my kernel has, of course, a custom configuration.

i regognized that compiling the kernel will result in 100% C0, but compiling chromium behaves like in my first post.
maybe there is some cpu throttling?
Back to top
View user's profile Send private message
audiodef
Watchman
Watchman


Joined: 06 Jul 2005
Posts: 5282

PostPosted: Thu Nov 29, 2012 2:13 pm    Post subject: Reply with quote

See what happens if you set MAKEOPTS="-j4". I'm not sure you're supposed to set this for more than the ACTUAL number of cores. Also, I've been told that setting MAKEOPTS to cores+1 provides no real benefit over setting it to to the number of cores exactly.
_________________
Gentoo Studio: http://gentoostudio.org
Facebook: http://www.facebook.com/gentoostudio
G+: https://plus.google.com/113947758237122861689/posts
Pappy's Kernel Seeds: http://kernel-seeds.org
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Kernel & Hardware All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum