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[Doug Smythies <1254920@xxxxxxxxxxxxxxxxxx>]

To clarify, I am suggesting that the reported numbers are incorrect, not
that there is some strange new loads going on.

I did many tests with disk I/O and CPU loading and such to determine if
there were any real increased overheads. Maybe a couple of percent of
CPU OS increased overhead and a little more on disk I/O.

Also, and in case anyone is interested, I graphed all of this stuff over many hours and two kernels.
see: http://ubuntuforums.org/showthread.php?t=2189769 the graphs are there.


** Attachment added: "The top info asked for."
   https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1254920/+attachment/3917148/+files/top.out

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https://bugs.launchpad.net/bugs/1254920

Title:
  CPU utilization / accounting issues

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  The issue is on a Trusty 32 bit server edition. It is the very very
  old computer that I use for minimum requirements testing.

  The issue is CPU user, sys, idle, and wait information makes absolutely no sense at all.
  For example with the commands "top" or "vmstat"
  I believe I have isolated the issue down to kernel configuration differences between Saucy and Trusty. I used the two otherwise same kernels from the ppa to come to this conclusion (after many many other kernels and such were tried). References:

  http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.12-saucy/
  http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.12-trusty/

  While there are a lot of configuration differences that are obviously
  not the issue (or so I think), there are many that I don't know if
  they could be or not. The computer I am using is too pathetic to
  compile the kernel (it takes 34 hours, and then it gives up before
  finishing anyhow).

  I will attach the config difference file in a moment.

  Automatic bug stuff has never worked for me on any of my computers,
  but I'll attach the other stuff asked for shortly.

  Example of expected vmstat output (server relatively idle):

  doug@test-smy:~/configs$ vmstat 20
  procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
   r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
   0  0    292   3952   4936  48668    0    0   247     5  265  151 14  7 77  2
   1  0    292   3912   4944  48708    0    0     2     2  252   50  0  0 100  0
   1  0    292   3912   4944  48708    0    0     0     0  252   47  0  0 100  0
   0  0    292   3900   4952  48708    0    0     0     2  252   49  0  0 99  1
   0  0    292   3900   4952  48708    0    0     0     1  252   51  0  0 100  0
   0  0    292   2636   4960  49928    0    0    61     1  253   56  0  0 99  1

  Example of vmstat output now (server idle):

  doug@test-smy:~$ vmstat 20
  procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
   r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
   0  0   5312   5544   3408  47900    8   22  1412    78 24253 4209 44 30  9 17
   0  0   5312   5528   3416  47916    0    0     0     1  252   41  0  0 40 60
   0  0   5312   5528   3416  47916    0    0     0     0  251   40  0 25  0 75
   0  0   5312   5528   3416  47916    0    0     0     0  252   39 17  0 50 33
   0  0   5312   5528   3416  47916    0    0     0     0  252   39  0  0 40 60
   0  0   5312   5516   3424  47916    0    0     0     1  252   41  0 25  0 75
   0  0   5312   5516   3424  47916    0    0     0     0  252   40  0 17 33 50

  doug@test-smy:~$ lsb_release -a
  No LSB modules are available.
  Distributor ID: Ubuntu
  Description:    Ubuntu Trusty Tahr (development branch)
  Release:        14.04
  Codename:       trusty
  doug@test-smy:~$ uname -a
  Linux test-smy 3.12.0-4-generic #10-Ubuntu SMP Thu Nov 21 22:11:22 UTC 2013 i686 i686 i686 GNU/Linux

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