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

[<spaminos-ker@yahoo.com>]

--- Con Kolivas <kernel@kolivas.org> wrote:
> Hi
> 
> I tried this on the latest staircase patch (7.I) and am not getting any 
> output from your script when tested up to 60 threads on my hardware. Can you 
> try this version of staircase please?
> 
> There are 7.I patches against 2.6.8-rc4 and 2.6.8-rc4-mm1
> 
> http://ck.kolivas.org/patches/2.6/2.6.8/
> 
> Cheers,
> Con
> 

Just tried on my machine:
2.6.8-rc4 fails all tests (did the test just to be sure)

2.6.8-rc4 with the "from_2.6.8-rc4_to_staircase7.I" patch and things look
pretty good:
on my hardware, I could put 60 threads too, and my shells are still very
responsive etc, and I get no slow downs with my watchdog script.

A few  strange things happened though (with 60 threads):
* after a few minutes, I got one message
Wed Aug 11 18:06:11 PDT 2004
>>>>>>> delta = 57
57 seconds !?! very surprising
* shortly after that, I tried to run top, or ps, and they all got stuck, I
waited a couple minutes and they were still stuck. I opened a few shells, I
could do anything but commands that enumerate the process list. After a while,
I killed the cputest program (ctrld c it), and the stucked ps/top continued
their execution.

I could not reproduce those problems ; I even rebooted the machine, but only
got one message delta of 3 every 30 minutes or so.

Nicolas