Re: [PATCH] implement nice support across physical cpus on SMP

[Con Kolivas <kernel@kolivas.org>]

On Sun, 8 May 2005 03:59, Carlos Carvalho wrote:
> Con Kolivas (kernel@kolivas.org) wrote on 7 May 2005 23:42:
>  >SMP balancing is currently designed purely with throughput in mind. This
>  >working patch implements a mechanism for supporting 'nice' across
>  > physical cpus without impacting throughput.
>  >
>  >This is a version for stable kernel 2.6.11.*
>  >
>  >Carlos, if you could test this with your test case it would be
>  > appreciated.
>
> Unfortunately it doesn't seem to have any effect:
>
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>   184 user1    39  19  7220 5924  520 R 99.9  1.1 209:40.68 mi41
>   266 user2    25   0  1760  480  420 R 50.5  0.1  86:36.31 xdipole1
>   227 user3    25   0  155m  62m  640 R 49.5 12.3  95:07.89 b170-se.x
>
> Note that the nice 19 job monopolizes one processor while the other
> two nice 0 ones share a single processor.
>
> This is really a showstopper for this kind of application :-(

Ok back to the drawing board. I have to try and figure out why it doesn't work 
for your case. I tried it on 4x with lots of cpu bound tasks so I'm not sure 
why it doesn't help with tyours.

Cheers,
Con

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