Help for very bad perf for MySQL

Josh Carroll josh.carroll at
Tue Nov 27 08:11:42 PST 2007

> Is Hyperthreading enabled  (by default it is not under
> FreeBSD)  mysql is heavily dependent on threading, if it is not
> built and linked into the freebsd threads package you will get
> poor performance.  Some folks have installed the linux compat libs
> and linked mysql into the linux threads package and reported good
> results.

Actually, on 6.2, it's better to use libthr instead of libpthread.
This can be done for MySQL only, but to test this without recompiling
MySQL, he can:

% echo "" >> /etc/libmap.conf

Then restart the mysql server and test again. I noticed a huge
increase in performance on 6.2 with libthr instead of libpthread. It
wasn't a 10x improvement, though, so there is definitely something
else going on with his setup.


More information about the freebsd-questions mailing list