PTHREAD_YIELDLOOPS boosts mysql super-smack performance

[Abdullah Ibn Hamad Al-Marri]

On Oct 31, 2007 5:31 AM, David Xu <davidxu at freebsd.org> wrote:
> I did a simple mysql super-smack benchmark test on a Intel XEON machine,
> the CPU has 4 cores:
>     CPU: Intel(R) Xeon(R) CPU            5130  @ 2.00GHz (1997.03-MHz)
>
>
> I have set environment variable LIBPTHREAD_YIELDLOOPS to 30 and start
> mysql server:
>
> setenv LIBPTHREAD_YIELDLOOPS 30
> /usr/local/etc/rc.d/mysql-server start
>
> and repeat doing
> #super-smack ./select-key.smack 10 20000
>
> The result is very surprising:
>
> # /usr/src/tools/tools/ministat/ministat normal.txt yield_30.txt
>
> x normal.txt
> + yield_30.txt
> +-----------------------------------------------------------------------------------------------------------------------------------------------------------+
> |  x  x x
>                                               +
>               |
> |  x xxxx
>                                          + + ++
>               |
> |x x xxxxx x
>                                        + + + ++        +
>               |
> |x x xxxxxxx   x      x
>                 +                    + + ++++++ ++++ +++  ++
>              +|
> |  |___A___|
>                                     |________M_A_________|
>               |
> +-----------------------------------------------------------------------------------------------------------------------------------------------------------+
>      N           Min           Max        Median           Avg        Stddev
> x  30      44790.57      48609.38     45831.065     45910.616     745.54679
> +  30      60521.95       73090.6     66008.135     66254.815     1953.4324
> Difference at 95.0% confidence
>          20344.2 +/- 764.241
>          44.3126% +/- 1.66463%
>          (Student's t, pooled s = 1478.47)
>
> it seems over 44% performance is improved.
>
>
> Regards,
> David Xu
>
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David thank you! }:)

When could you please commit these changes of libthr will hit RELENG_7
so we could benefit of these improvements?

-- 
Regards,

-Abdullah Ibn Hamad Al-Marri
Arab Portal
http://www.WeArab.Net/