Re: Possible Threading problem with -CURRENT / MySQL?

On 14/06/2004 17:43, Robert Watson wrote:
> On Mon, 14 Jun 2004, Lasse Laursen wrote:
> 
> > Also on a SMP machine? I think that the problem is somehow related to
> > SMP machines since the problems started when we moved to a SMP box :(
> 
> If you haven't already, it would certainly be worth removing SMP from the
> kernel on that box and just running a UP kernel to confirm that it's a
> problem using SMP.  I don't doubt it's the case, but it's worth checking
> anyway to be sure.

I have a similar smp config (dell poweredge 2650, dual Xeon 2.8, RAID5)

I have best performance with linux 2.4.21-smp (not tried 2.6),
but very poor (5x less) with mysqld using libpthreads on CURRENT.
mysqld process is always in state 'kserel' or sometimes '*Giant'

http://grumly.eu.org/~ced/dmesg.txt
http://grumly.eu.org/~ced/CED-SMP.txt (no invariants, no witness)

mysqld with linuxthreads seems to work better ... 
and even better with libc_r (but using only 1 cpu)

Everything with HTT disabled in bios. Enabling HTT gives even worst
performance :/

-- 
Cédric Tabary