2 x quad-core system is slower that 2 x dual core on FreeBSD

[Alexey Popov]

Hi.

Ivan Voras wrote:
>> last pid:  5266;  load averages: 24.67, 22.65, 17.44       up 0+03:56:38
>> 121 processes: 41 running, 62 sleeping, 18 waiting
>> CPU states:  9.5% user,  0.0% nice, 82.0% system,  0.5% interrupt,  8.0%
>> idle
> This is really unusual - the number of processes is not that high, but
> if I'm reading the line from systat correctly, you have unusually many
> context switches:
>   r   p   d   s   w   Csw  Trp  Sys  Int  Sof  Flt        cow   16839 total
>  27       1  39      137k 3390  33k 2490  313 2519   2519 zfod
> sio0 irq4
> nginx or similar asynchronous web servers should reduce inter-process
> contention context switches dramatically, but you say that it didn't
> work as such so the problem might be somewhere else.
> Try sending a 10-second or so output from vmstat to confirm this problem.
Yes, there's really many context switches:

%vmstat 1
  procs      memory      page                   disk   faults      cpu
  r b w     avm    fre   flt  re  pi  po    fr  sr mf0   in   sy   cs us 
sy id
23 1 0  615284 3581456 15980   0   0   0 15964   0   0 1414 58211 115230 
25 60 15
24 0 0  631668 3564976  9940   0   0   0  5793   0   0  664 30036 158059 
11 79 10
20 0 0  655220 3545516 22146   0   0   0 16731   0   0 1992 77638 116627 
31 65  4
23 0 0  622452 3579700 18248   0   0   0 27451   0   0 1839 80646 115798 
38 59  3
15 9 0  614260 3587484  4795   0   0   0  6765   0   0  352 23938 159993 
  6 83 11
21 0 0  625524 3567948 10154   0   0   0  5308   0   0  653 32718 159119 
11 81  8
13 3 0  627572 3571924 15266   0   0   0 16278   0   0 1031 50321 142111 
20 69 11
21 0 0  605044 3591860  9008   0   0   0 14021   0   0  873 42083 160441 
13 79  8
19 1 0  611188 3593404  7498   0   0   0  7920   0   0  489 30012 158176 
10 77 13
24 0 0  610164 3592360  5855   0   0   0  5602   0   0  666 26627 162937 
  8 81 11
20 3 0  622452 3587456  6372   0   0   0  5144   0   0  362 23705 161257 
10 81 10
^C
%

> If you can, attach a ktrace(1) to one of the httpd processes that
> consumes CPU, and send the processed kdump output.
Here is it: http://83.167.98.162/gprof/kdump.txt.gz

> Also, did you try configuring and running pecl-APC for PHP?'s
I'm using eAccelerator. Again, the same soft works good on less-CPU 
system and on Linux.

With best regards,
Alexey Popov