Re: Scheduler oddness
jakob@ostenfeld.dk
Fri, 5 Mar 1999 00:34:41 +0100
On Thu, Mar 04, 1999 at 06:53:41PM -0500, Rui Sousa wrote:
...
>
> Three processes ("niced" to 19)
>
> PID USER PRI NI SIZE RSS SHARE STAT LIB %CPU %MEM TIME
> COMMAND
> 328 rsousa 20 19 16116 14M 420 R N 0 78.7 11.5 58:15
> cpw_md5.exe
> 322 rsousa 20 19 16208 15M 520 R N 0 64.2 12.5 38:37
> cpw_md3.exe
> 325 rsousa 20 19 45112 42M 516 R N 0 54.2 34.2 57:41
> cpw_md3.exe
>
> difference in cpu time (328-325) 00:34
> difference in cpu time (328-322) 19:38
>
> after some minutes:
>
> PID USER PRI NI SIZE RSS SHARE STAT LIB %CPU %MEM TIME
> COMMAND
> 325 rsousa 19 19 45112 42M 516 R N 0 85.8 34.2 64:04
> cpw_md3.exe
> 322 rsousa 20 19 16208 15M 520 R N 0 61.0 12.5 45:17
> cpw_md3.exe
> 328 rsousa 19 19 16116 14M 420 R N 0 52.2 11.5 64:04
> cpw_md5.exe
>
> difference (328-325) 00:00
> difference (328-322) 18:47
>
> time elapsed (328) 05:49
>
> The processes are definitely not getting the same amount of cpu. They
> are almost identical programs (number crunching) with just different
> inputs.
If you give them different inputs, the processes are not identical.
Could it be, that one process generates a larger number of cache misses than
the other ? It seems that both SIZE and RSS is pretty much different
from process to process. Try running three copies of the same program with
exactly the same input, ant let us know what happened.
................................................................
: jakob@ostenfeld.dtu.dk : And I see the elder races, :
:.........................: putrid forms of man :
: Jakob Østergaard : See him rise and claim the earth, :
: OZ9ABN : his downfall is at hand. :
:.........................:............{Konkhra}...............:
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