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Date:      Wed, 10 Dec 2003 23:03:17 -0500 (EST)
From:      Jeff Roberson <jroberson@chesapeake.net>
To:        Andy Farkas <andyf@speednet.com.au>
Cc:        current@freebsd.org
Subject:   Re: ULE and current.
Message-ID:  <20031210230206.R4201-100000@mail.chesapeake.net>
In-Reply-To: <20031211085336.O13173@hewey.af.speednet.com.au>

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On Thu, 11 Dec 2003, Andy Farkas wrote:

>
> The scheduling of nice processes seems to be broken:

This is actually a problem in the load balancer.  It's not taking nice
into consideration when attempting to balance the load.

>
> team2# nice -7 sh -c "while :; do echo -n;done" &
> team2# nice -7 sh -c "while :; do echo -n;done" &
> team2# sleep 120; top -S
>
>   PID USERNAME   PRI NICE   SIZE    RES STATE  C   TIME   WCPU    CPU COMMAND
>   675 root       133   -7  1576K   952K CPU1   1   1:52 75.78% 75.78% sh
>   676 root       133   -7  1576K   952K RUN    1   1:39 73.44% 73.44% sh
>    12 root       -16    0     0K    12K RUN    0  18:46 55.47% 55.47% idle: cpu0
>    11 root       -16    0     0K    12K RUN    1   7:00  0.00%  0.00% idle: cpu1
>
>
> Adding a third nice process eliminates the idle time, but cpu% is still bad:
>
> team2# nice -7 sh -c "while :; do echo -n;done" &
> team2# sleep 120; top -S
>
>   PID USERNAME   PRI NICE   SIZE    RES STATE  C   TIME   WCPU    CPU COMMAND
>   705 root       133   -7  1576K   952K CPU0   0   1:53 100.78% 100.78% sh
>   675 root       133   -7  1576K   952K RUN    1  12:12 51.56% 51.56% sh
>   676 root       133   -7  1576K   952K RUN    1  11:30 49.22% 49.22% sh
>   729 root        76    0  2148K  1184K CPU1   1   0:00  0.78%  0.78% top
>    12 root       -16    0     0K    12K RUN    0  24:00  0.00%  0.00% idle: cpu0
>    11 root       -16    0     0K    12K RUN    1   7:00  0.00%  0.00% idle: cpu1

I agree that 100.78% is wrong.  Also, the long term balancer should be
kicking one sh process off of the doubly loaded cpu every so often.  I'll
look into this, thanks.

Cheers,
Jeff

>
>
> The box is a dual P133 running -current from 8th Dec.
>
> --
>
>  :{ andyf@speednet.com.au
>
>         Andy Farkas
>     System Administrator
>    Speednet Communications
>  http://www.speednet.com.au/
>
>



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