Performance issue

Kipp Holger h.kipp at
Mon May 9 09:57:42 PDT 2005

Same test on a 5.3-STABLE from 31.01.2005:

       81,90 real        77,05 user         3,51 sys
     22908  maximum resident set size
       620  average shared memory size
     20083  average unshared data size
       128  average unshared stack size
      5379  page reclaims
        26  page faults
         0  swaps
        36  block input operations
         0  block output operations
         0  messages sent
         0  messages received
         0  signals received
        62  voluntary context switches
     10623  involuntary context switches

This is a on a slow dual-processor system:

Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel Pentium III (732.98-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x683  Stepping = 3
real memory  = 2281635840 (2175 MB)
avail memory = 2232012800 (2128 MB)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1

(if this is of any help). Scheduler is 4BSD.

Holger Kipp

-----Original Message-----
From: owner-freebsd-stable at on behalf of Pete French
Sent: Mon 09.05.2005 18:10
To: ewan at; freebsd-stable at
Subject: Re: Performance issue
> Whereas, the typical result for the new rig looked more like
>       105.36 real        71.10 user        33.41 sys
>      10548  involuntary context switches

Now I just ran this test myself. This machine is a 2.4 gig P4 with
hyperthreading enabled. Much as I am an AMD fan, I would expect a 1gig
Athlon to be significantly slower than a 2.4 gig Pentium 4. 


       93.45 real        56.55 user        36.85 sys
      1857  involuntary context switches

Uhhh... so it takes almost the same time to do the calculation, but spends
actually *more* of it in system space. Does far less context switches though,
but I am assuming thats due to HTT.

Numbers look very odd to me. So I then ran it on another P4 system we have
round here which is still running 4.11. This is a 2.66 gig P4, not a 2.4
so it should be a bit faster, but:

       33.77 real        33.49 user         0.07 sys
       711  involuntary context switches

Over two and a half times faster ?! Thats not right at all!

All the new systems I have tried are 5.4-RC4, so should be the
latest and greatest. When my colleague finishes on his machine I
can try a GENERIC 5.4-RC4 kernel on another P4 and see what that

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