FreeBSD MySQL still WAY slower than Linux
Daniel Eischen
eischen at vigrid.com
Sat Jun 11 16:02:35 GMT 2005
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
More information about the freebsd-stable
mailing list