Why is MySQL nearly twice as fast on Linux?

[Daniel Eischen]

On Sun, 23 May 2004, mike wrote:
> > >
> > Note that default mysql table type is mysql, which uses Giant Lock when
> > doing update on table, it does not support concurrent update, each thread
> > wants to update the table will be serialized, fix me if I am wrong, but some
> > years ago, mysql book tells me the fact, you might need to look other types,
> > for example, BDB or innodb. 50% cpu usage on SMP machine is normal for
> > MySQL server using mysql table type.
> >
> > David Xu
> 
> i just want to note - either way, running the same benchmarking utilities
> on linux shows linux outperforming freebsd hands down.
> 
> this isn't a theoretical debate on why mysql performance might be slow. it
> works fine on linux - our question is why we can't get that type of
> performance out of freebsd.
> 
> to reiterate for the nth time - i'm pledging $250 to whomever will own
> this/fix it. i believe two other parties will pledge another combined $250
> as well.
> 
> that's $500 to do something that [overall] benefits freebsd users,
> especially those wishing to run high performance mysql servers on freebsd.
> 
> we want it to at least match linux performance, if not be able to exceed
> it.
> 
> right now we're just going in loops with requests for more benchmarks and
> such. if it's worth $500, someone "in the know" step up and we'll give you
> access to one of our boxes, you can do whatever you want to get it to
> perform how we'd like. at least 2 or 3 of us have pretty similarly
> configured machines, so if you can get it to work good on one, that should
> be able to be applied to all, if it's not a permanent obvious fix in the
> freebsd kernel, scheduler, threading, or just a patch to get more out of
> mysql on freebsd 5.x.

There are people putting in a lot of time into locking down
the kernel.  We used to have people getting paid full-time
to work on the kernel, but I don't think that's the case
any longer (for certain, there are fewer of them).  Unfortunately
I don't think this is something you can throw a few hundred
dollars at and get a 20 man-hour fix.