Michal Piotrowski wrote:
> Hi,
> here are schedulers benchmark (part2):
> [bits deleted]

Here's a summary of your output generated using the attached Python script.

              |         Build Statistics | Overall Statistics
-----------------------------------------------------------------------
     Scheduler|   Real    CPU  SYS   TPT |    CPU   TPT    delay    CXSW
              | (secs) (secs)  (%)   (%) | (secs)   (%)  (secs)
-----------------------------------------------------------------------
     ingosched| 3128.5 5056.3 8.18 161.6 | 5379.5 171.9 159367.4 1556452
     staircase| 3131.2 5032.6 8.09 160.7 | 5352.9 170.9 135193.0 1670366
spa_no_frills| 3103.8 5049.5 7.98 162.7 | 5266.7 169.7 172384.8  520937
   zaphod(d,d)| 3561.7 4823.8 9.25 135.4 | 5132.0 144.1 148361.5 1771617
   zaphod(d,0)| 3551.2 4809.9 9.19 135.4 | 5114.7 144.0 144022.0 1784814
   zaphod(0,d)| 3126.8 5063.2 8.11 161.9 | 5278.1 168.8 173438.4  573587
   zaphod(0,0)| 3105.5 5052.9 7.98 162.7 | 5254.8 169.2 165774.4  577534
     nicksched| 3294.7 5095.1 9.10 154.6 | 5425.4 164.6 104298.2 2205665

where the (x,y) after zaphod means (max_ia_bonus, max_tpt_bonus) and "d" 
means default.  I had to kill a few significant digits to squeeze it 
into 71 columns.  Overall statistics are extracted from the schedstats 
data.  In the "Build Statistics" "CPU" is the sum of the user and sys 
times and "SYS" is the percentage of that which was sys time (as I feel 
that is a better thing to compare than raw sys times).

I was intrigued by the fact that zaphod(d,d) and zaphod(d,0) take longer 
in real time but use less cpu.  I was assuming that this meant that some 
other job was getting some cpu but the schedstats data doesn't support 
that.  Also it wouldn't make sense anyway as you'd expect jobs doing the 
same amount of work to use roughly the same amount of cpu.  My latest 
theory is that your machine has hyper threads and this artifact is 
caused by the mechanism in the scheduler for handling tasks with 
differing priority in sibling hyper thread channels.  Does your system 
have hyper threads?

Peter
-- 
Peter Williams                                   pwil3058@bigpond.net.au

"Learning, n. The kind of ignorance distinguishing the studious."
  -- Ambrose Bierce