FreeBSD MySQL still WAY slower than Linux

[Daniel Eischen]

Robert Watson wrote:
> 
> On Fri, 10 Jun 2005, Steve Roome wrote:
> 
>> We're using mostly:
>>
>>  5.4-STABLE FreeBSD 5.4-STABLE #0: Mon Jun 6 12:22:18 BST 2005
> 
> 
> In my experience, the following factors make a big performance difference:
> 
> - Thread package.  In 5.x, you get process scope threads by default, but
>   it turns out MySQL is tuned for system scope threads, and this is
>   particularly visible in the supersmack benchmark, which competes many
>   client processes against a few server threads.  I'm not sure what the
>   condition is of libthr on 5.x, but you could give it a spin.  In 6.x,
>   libthr has been largely rewritten and is a great deal faster.  I think
>   there's a compile-time option to make libpthread use system scope
>   threads but the details ellude me.  The Linuxthreads library may well
>   provide a substantial improvement -- not as good for MySQL as the 6.x
>   libthr, but perhaps much more appropriate than libpthread.

You can set the environment variable LIBPTHREAD_SYSTEM_SCOPE to force
libpthread to use system scope.  This is easier than rebuilding libpthread
(with SYSTEM_SCOPE_ONLY defined) and allows you to use M:N for some
applications and 1:1 for others.

-- 
DE