Re: Scheduler fairness problem on 2.6 series (Attn: Nick Piggin and others)

[Peter Williams <pwil3058@bigpond.net.au>]

spaminos-ker@yahoo.com wrote:
> --- Peter Williams <pwil3058@bigpond.net.au> wrote:
> 
> 
>>Could you try it in "pb" mode with both max_ia_bonus and max_tpt_bonus 
>>set to zero?  That will disable all "priority" fiddling and tasks should 
>>just round robin at a priority determined solely by their "nice" value 
>>and since (according to your earlier mail) all the daemons have the same 
>>"nice" value they should just round robin with each other.
> 
> 
> 
> Hi, I tried the latest  V-5.0 patch over 2.6.8.1 in these conditions with the
> actual server subsystem, and I get components timeouts :(
> I also ran the watchdog script on the box while running the test, and saw
> deltas of around 3 seconds every few hours:
> 
> Tue Aug 24 03:02:13 PDT 2004
> 
>>>>>>>>delta = 3
> 
> Tue Aug 24 05:50:14 PDT 2004
> 
>>>>>>>>delta = 3
> 
> Tue Aug 24 09:05:24 PDT 2004
> 
>>>>>>>>delta = 4
> 
> Tue Aug 24 09:06:20 PDT 2004
> 
>>>>>>>>delta = 4
> 
> Tue Aug 24 09:36:22 PDT 2004
> 
>>>>>>>>delta = 3
> 
> Tue Aug 24 10:20:16 PDT 2004
> 
>>>>>>>>delta = 3
> 
> Tue Aug 24 13:28:19 PDT 2004
> 
>>>>>>>>delta = 3
> 
> 
> Could I do something more useful than just displaying those deltas? Maybe I
> could dump the process list in some way, or enable some debugging code in the
> kernel to find out what is going on?

You could try Lee Revell's (rlrevell@joe-job.com) latency measuring 
patches and also try applying Ingo Molnar's (mingo@elte.hu) 
voluntary-preempt patches.

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

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