Performance issue

Mike Jakubik
Mon, 09 May 2005 11:26:45 -0000

On Mon, May 9, 2005 1:06 pm, Scott Long said:

> 5.3 ships with SMP turned on, which makes lock operations rather
> expensive on single-processor machines.  4.x does not have SMP turned on by
> default.  Would you be able to re-run your test with SMP turned off?

This is what i get on my system, which has debugging and smp off in the
kernel.

FreeBSD 6.0-CURRENT #0: Tue May  3 23:55:43 EDT 2005
    root@fbsd.wettoast.net:/usr/obj/usr/src/sys/DP
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: AMD Athlon(tm) Processor (1410.21-MHz 686-class CPU)
  Origin = "AuthenticAMD"  Id = 0x644  Stepping = 4

Features=0x183f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR>
  AMD Features=0xc0440000<RSVD,AMIE,DSP,3DNow!>

---
       76.89 real        49.33 user        22.87 sys
     23116  maximum resident set size
       686  average shared memory size
     20795  average unshared data size
       127  average unshared stack size
      5380  page reclaims
         0  page faults
         0  swaps
         0  block input operations
         0  block output operations
         0  messages sent
         0  messages received
         0  signals received
         1  voluntary context switches
     10018  involuntary context switches
---

As we can see, it is still spending a lot of time in system, and there are
a lot of context switches being done.