Re: OSDL DBT-2 w/ PostgreSQL 7.3.4 and 7.4beta5
Mark Wong <markw@osdl.org>
From: Mark Wong <markw@osdl.org>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@postgresql.org, osdldbt-general@lists.sourceforge.net
Date: 2003-11-02T02:00:35Z
Lists: pgsql-hackers
On Sat, Nov 01, 2003 at 02:37:21PM +0100, Manfred Spraul wrote: > Tom Lane wrote: > > >markw@osdl.org writes: > > > > > >>7.4beta5 offers more throughput. One significant difference I see is in > >>the oprofile for the database. For the additional 7% increase in the > >>metric, there are about 32% less ticks in SearchCatCache. > >> > >> > > > >Hmm. I have been profiling PG for some years now, and I cannot remember > >ever seeing a profile in which SearchCatCache topped everything else > >(the usual suspects for me are palloc/pfree support code). Can you give > >any explanation why it looks like that? Can your profiling code tell > >where the hotspot call sites of SearchCatCache are? > > > If I understand the docs correctly, op_to_source -a can do that - the > result is annotated assembly, with percentage numbers for each > instruction. If the sources were compiled with -g2, even source level > annotation is possible. > > Mark, do you still have the oprofile output? I don't understand why so > much time is spent in the kernel signal handlers, i.e. I could use > annotated assembly or source of linux/kernel/signal.c. I've rerun a test, capturing the raw oprofile output, running opannotate for source and assmebly output (links for each should be on the page now.) Let me know if I've missed anything: http://developer.osdl.org/markw/dbt2-pgsql/190/ I'm running a test with your patch now too. I should have results shortly. Thanks, Mark