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

[spaminos-ker]

--- William Lee Irwin III <wli@xxxxxxxxxxxxxx> wrote:
> 
> Wakeup bonuses etc. are starving tasks. Could you try Peter Williams'
> SPA patches with the do_promotions() function? I suspect these should
> pass your tests.
> 
> 
> -- wli
> 

I tried the patch-2.6.7-spa_hydra_FULL-v4.0 patch

I only changed the value of /proc/sys/kernel/cpusched/mode to switch between
different patches.

The 2 threads test passes successfuly (improvement over stock 2.6.7) but none
passed the 20 threads test:

eb

Tue Aug 10 19:10:48 PDT 2004
>>>>>>> delta = 6
Tue Aug 10 19:11:03 PDT 2004
>>>>>>> delta = 16
Tue Aug 10 19:11:13 PDT 2004
>>>>>>> delta = 9
Tue Aug 10 19:11:24 PDT 2004
>>>>>>> delta = 11
Tue Aug 10 19:11:34 PDT 2004
>>>>>>> delta = 10
Tue Aug 10 19:11:45 PDT 2004
>>>>>>> delta = 11
Tue Aug 10 19:11:56 PDT 2004
>>>>>>> delta = 11
Tue Aug 10 19:12:06 PDT 2004
>>>>>>> delta = 10



pb

Tue Aug 10 19:07:52 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:07:55 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:07:59 PDT 2004
>>>>>>> delta = 4
Tue Aug 10 19:08:02 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:08:05 PDT 2004
>>>>>>> delta = 3

sc

Tue Aug 10 19:08:28 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:09:08 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:09:17 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:09:23 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:09:49 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:09:53 PDT 2004
>>>>>>> delta = 3
Tue Aug 10 19:09:55 PDT 2004
>>>>>>> delta = 3


eb seemed to be the worst of the bunch with quite long system hangs on this
particular test.
With the default settings of:

base_promotion_interval 255
compute 0
cpu_hog_threshold 900
ia_threshold 900
initial_ia_bonus 1
interactive 0
log_at_exit 0
max_ia_bonus 9
max_tpt_bonus 4
sched_batch_time_slice_multiplier 10
sched_iso_threshold 50
sched_rr_time_slice 100
time_slice 100

I am not very familiar with all the parameters, so I just kept the defaults

Anything else I could try?

Nicolas


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