Hi Nick,

Here are the results of the comparisons I said I would do.

no-hyperthreading:
	http://developer.osdl.org/markw/dbt2-pgsql/282/
	- metric 2288.43
	- baseline

hyperthreading:
	http://developer.osdl.org/markw/dbt2-pgsql/278/
	- metric 1944.42
	- 15% throughput decrease
	
hyperthreading w/ Ingo's C1 patch:
	http://developer.osdl.org/markw/dbt2-pgsql/277/
	- metric 1978.39
	- 13.5% throughput decrease

hyperthreading w/ Nick's w26 patch:
	http://developer.osdl.org/markw/dbt2-pgsql/274/
	- metric 1955.91
	- 14.5% throughput decrease

It looks like there is some marginal benefit to your or Ingo's patches
with a workload like DBT-2.  I probably don't understand enough about
hyperthreading, but I wonder if there's something PostgreSQL can do to
take advantage of hyperthreading

Anyway, each link has pointers to readprofile and annotated oprofile
assembly output (if you find that useful.)  I haven't done enough tests
to have an idea of the error margin, but I wouldn't be surprised if it's
at least 1%.

Let me know if there's anything else you'd like me to try.

Thanks,
Mark

Fri, 12 Dec 2003 14:28:21 -0800 (PST)
markw@osdl.org
more dbt-2 results hyperthreading on linux-2.6.0-test11