Re: cross-cpu balancing with the new scheduler

[Manfred Spraul <manfred@colorfullife.com>]

Davide Libenzi wrote:
> 
> I've a very simple phrase when QA is bugging me with these corner cases :
> 
> "As Designed"
> 
> It's much much better than adding code and "Return To QA" :-)
> I tried priority balancing in BMQS but i still prefer "As Designed" ...
>
Another test, now with 4 process (dual cpu):
#nice -n 19 ./eatcpu&
#nice -n 19 ./eatcpu&
#./eatcpu&
#nice -n -19 ./eatcpu&

And the top output:
<<<<<<
73 processes: 68 sleeping, 5 running, 0 zombie, 0 stopped
CPU0 states: 100.0% user,  0.0% system, 100.0% nice,  0.0% idle
CPU1 states: 98.0% user,  2.0% system, 33.0% nice,  0.0% idle
[snip]
PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
 1163 root      39  19   396  396   324 R N  99.5  0.1   0:28 eatcpu
 1164 root      39  19   396  396   324 R N  33.1  0.1   0:11 eatcpu
 1165 root      39   0   396  396   324 R    33.1  0.1   0:07 eatcpu
 1166 root      39 -19   396  396   324 R <  31.3  0.1   0:06 eatcpu
 1168 manfred    1   0   980  976   768 R     2.7  0.2   0:00 top
[snip]

The niced process still has it's own cpu, and the "nice -19" process has
33% of the second cpu.

IMHO that's buggy. 4 running process, 1 on cpu0, 3 on cpu1.

--
	Manfred