Which SCHED_ for DB server

[NAKATA Maho]

In Message-ID: <20050906000016.GA91835 at xor.obsecurity.org> 
Kris Kennaway <kris at obsecurity.org> wrote:

> On Thu, Sep 01, 2005 at 10:53:39AM +0200, Claus Guttesen wrote:
> > > I'm building a server that will run PostgreSQL with a database
> > > containing several 10s of million records. The only things happening on
> > > this box will be the SQL processes and other processes to parse raw data
> > > and load into the DB. Users = a few connections via HTTP from an
> > > intranet server (not more than 5 concurrently).
> > > 
> > > I was wondering what is the best SCHED_ to set in the kernel.
> > > I currently have SCHED_4BSD but was wondering if _ULE would be better
> > > for this
> > 
> > For prod. use I would recommend SCHED_4BSD atm. The 4BSD-scheduler
> > does seem to be more stable on SMP and up.
> 
> ULE might be OK on SMP with 6.0 and above, but performance seems to be
> a bit lower than 4BSD in my tests.  Try it yourself and see which is
> better.

I tried different matter, but my result shows:
for 5.4-RELEASE, ule is 1.5 times slower than 4bsd.
See also PR: 85820 for details.

thanks!
-- NAKATA, Maho (maho at FreeBSD.org)