2 x quad-core system is slower that 2 x dual core on FreeBSD

[Robert Watson]

On Mon, 19 Nov 2007, Alexey Popov wrote:

> Robert Watson wrote:
>> FreeBSD 7 contains significant optimization for increased numbers of cores, 
>> and is where a lot of the work optimizing MySQL has ended up.  I see you're 
>> trying out a 6.3 beta, any chance you could try out a 7.0 beta instead? 
>> Also, consider switching to "options SCHED_ULE" in the 7.0 kernel rather 
>> than "options SCHED_4BSD".
> I tried SCHED_ULE, but got no difference:

Did you see no change in throughput, or no change in reported CPU use?

We should probably take this thread to performance@ and get Kris involved.  He 
may be interested in trying to reproduce your workload in our testbed so we 
can perform measurements of our own, as well as getting you to provide 
profiling information.  One of the things we'd most like to have are nice 
potted benchmarks for real-world workloads, as that allows us to easily replay 
them, perform measurements, optimize, etc.

Thanks,

Robert N M Watson
Computer Laboratory
University of Cambridge

>
> last pid:  1063;  load averages: 22.75, 13.76,  6.31    up 0+00:07:24 
> 17:53:49
> 56 processes:  33 running, 23 sleeping
> CPU states: 26.5% user,  0.0% nice, 68.1% system,  0.3% interrupt,  5.1% idle
> Mem: 365M Active, 20M Inact, 102M Wired, 664K Cache, 46M Buf, 3419M Free
> Swap: 2048M Total, 2048M Free
>
>  PID USERNAME   THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU COMMAND
> 1019 www          1 101    0   101M 51244K RUN    6   0:37 26.86% httpd
> 1040 www          1  -4    0 92476K 42956K RUN    1   0:36 26.76% httpd
> 1004 www          1  -4    0 92476K 42864K RUN    4   0:38 25.98% httpd
> 1018 www          1 101    0 91452K 41736K CPU3   3   0:37 25.68% httpd
> 1000 www          1 101    0 92476K 42544K RUN    0   0:36 25.29% httpd
> 1026 www          1 101    0 93500K 39900K CPU0   0   0:35 25.20% httpd
> 1021 www          1 101    0   101M 49432K RUN    4   0:37 25.10% httpd
> 1024 www          1 101    0 93500K 44416K RUN    5   0:37 25.10% httpd
> 1020 www          1 101    0 94524K 43684K RUN    0   0:37 25.00% httpd
> 1030 www          1 101    0 96576K 46004K RUN    3   0:36 25.00% httpd
> 1031 www          1 101    0   101M 50956K RUN    3   0:37 24.66% httpd
> 1025 www          1 101    0 94524K 43880K RUN    5   0:36 24.56% httpd
> 1041 www          1 101    0 92476K 41792K RUN    2   0:36 24.56% httpd
> 1022 www          1 101    0   101M 48932K RUN    5   0:36 24.27% httpd
>
> With best regards,
> Alexey Popov
>